Energy Tech Laboratories MR212 User's Manual
Contents
1. 11 Main Burner Adjustment 12 Heater Start Up Summary 13 Final Start Up Procedure 14 Pulley Adjustment 14 Pulley Alignment 14 Proper Belt Tension 14 Pulley Combination Chart 15 Sequence of Operation 16 Flame Safety Control 16 Air Flow Switch2. 16 Modulating Gas System 17 High Temperature Limit 17 Operation Summary 17 Optional Remote Panel Circuit 18 Components 19 Remote Panel Option 20 Troubleshooting 21 Airflow Troubleshooting Chart 21 Burner Troubleshooting Chart 22 Remote Panel Troubleshooting Chart
3. 7 Gas 8 Electrical 9 Motorized Intake Damper 9 Remote Control Panel 10 Fan to Building Wiring Connection 10 OPERATION 11 Start Up 11 Special Tools Required 11 Start Up Procedure 11 Pilot Adjustment
4. 4 INSTALLATION 5 Mechanical 5 Site Preparation 5 Assembly 5 Curb and Ductwork 5 Roof Mount Installation 6 Installation with Exhaust Fan 6 Direct Fired Module Installation 7 Indoor INLINE Installation 7 Heat Module Add On Installation
5. 28 Maintenance Record 28 Factory Service Department 28 4 WARRANTY This equipment is warranted to be free from defects in materials and workmanship under normal use and service for a period of 12 months from date of shipment This warranty shall not apply if 1 The equipment is not installed by a qualified installer per the MANUFACTURER S installation instructions shipped with the product 2 The equipment is not installed in accordance with federal state and local codes and regulations 3 The equipment is misused or neglected 4 The equipment is not operated within its published capacity 5 The invoice is not paid within the terms of the sales agreement The MANUFACTURER shall not be liable for incidental and consequential losses and damages potentially attributable to malfunctioning equipment Should any part of the equipment prove to be defective in material or workmanship within the 12 month warranty period upon examination by the MANUFACTURER such part will be repaired or replaced by MANUFACTURER at no charge The BUYER shall pay all labor costs incurred in connection with such repair or replacement Equipment shall not be returned without MANUFACTURER S prior authorization
6. 23 Troubleshooting Flowcharts 24 MAINTENANCE 25 General Maintenance 25 2 weeks after startup 26 Every 3 months 26 Filter Quantity Chart 26 Yearly 26 Start Up and Maintenance Documentation 28 Job Information 28 Heater Information
7. 0 00 1 00 2 00 3 00 4 00 5 00 6 00 0 100000 200000 300000 400000 500000 600000 Firing Rate BTU Hr Ft of Burner Manifold Pressure in w c Natural Gas Propane Gas Main Burner Adjustment 1 Once the pilot has been properly established the manifold gas pressure or temperature rise should be adjusted to jobsite conditions The gas pressure regulator integral to the combination gas control on size 1 3 heaters and located in the modulating valve on size 4 5 heaters is adjusted at the factory for average gas conditions It is important that the gas be supplied to the burner in accordance with the input rating on the rating plate 2 Create a high fire call for heat This should be done with the blower on and all gas controls on High fire can be achieved by removing the wire at terminal 4 remove wires 2 and 4 for Maxitrol 44 systems from the Maxitrol 14 amplifier 3 The manifold pressure should be checked at the pressure tap downstream of the modulating valve The graph to the right indicates the proper manifold pressure for the desired amount of BTUs per foot of burner For natural gas systems the high fire manifold pressure should not exceed 5 in w c For propane gas the high fire manifold pressure should not exceed 2 5 in w c Another method of checking high fire is to measure the temperature rise of the unit The temperature rise should be set to design conditions and typically is minimum 70
8. 1 Fan inlet and approaches to ventilator should be kept clean and free from any obstruction 2 Motors are normally permanently lubricated Check bearings periodically If they have grease fittings lubricate each season Use caution when lubricating bearings wipe the fittings clean the unit should be rotated by hand while lubricating Caution Use care when touching the exterior of an operating motor Motors normally run hot and may be hot enough to be painful or cause injury 3 All fasteners should be checked for tightness each time maintenance checks are preformed prior to restarting unit 4 Blowers require very little attention when moving clean air Occasionally oil and dust may accumulate causing imbalance If the fan is installed in a corrosive or dirty atmosphere periodically inspect and clean the wheel inlet and other moving parts to ensure smooth and safe operation Re Setting Of The Unit If the flame safety control is locked out alarm light on reset the unit by 1 Turn OFF Power to the unit 2 Turn Power to the unit back ON Emergency shutdown of unit To shut down the unit in the event of an emergency do the following 1 Turn power OFF to the unit from main building disconnect 2 Turn the external disconnect switch to the OFF position 3 CLOSE the inlet gas valve located on the heater Prolonged shutdown of the unit For prolonged shutdown the following steps should be done 1 Turn the external disconnect switch t
9. 6 Wire the sensor as indicated on the supplied wiring schematic Run all wiring within metal conduit Supply 120V AC to terminals 1 and N in the direct fired module 7 Follow the start up instructions located in this manual 8 Gas Pressure Table Gas Pressure Type Gas Pressure Size 1 3 Inlet Pressure 7 in w c 14 in w c Size 4 5 Inlet Pressure 7 in w c 5 psi Max Manifold Pressure Natural Gas 5 in w c maximum Max Manifold Pressure Propane 2 5 in w c maximum Gas Connection Sizes Unit Size Gas Pipe Size NPT Size 1 Size 2 1 Size 3 1 Size 4 1 1 4 Size 5 1 1 2 Gas Connection Diagram Gas Installation of gas piping must conform with local building codes or in the absence of local codes with the National Fuel Gas Code ANSI Z223 1 NFPA 54 latest edition In Canada installation must be in accordance with CAN CGA B149 1 for natural gas units and CAN CGA B149 2 for propane units WARNING INLET GAS PRESSURE MUST NOT EXCEED PRESSURE INDICATED ON NAMEPLATE SEE UNIT NAMEPLATE FOR PROPER GAS SUPPLY PRESSURE AND GAS TYPE 1 Always disconnect power before working on or near a heater Lock and tag the disconnect switch or breaker to prevent accidental power up 2 Piping to the unit should conform with local and national requirements for type and volume of gas handled and pressure drop allowed in the line Refer to the Gas Engineer s Handbook for gas line ca
10. 6 3 6 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 AK114 11 11 2 400 416 431 447 462 477 493 508 524 539 554 AK94 9 9 2 488 506 525 544 563 581 600 619 638 656 675 AK79 7 5 7 7 582 605 627 650 672 694 717 739 762 784 806 AK66 6 2 6 4 701 728 755 782 809 836 863 889 916 943 970 AK54 5 5 2 863 896 929 962 995 1028 1062 1095 1128 1161 1194 AK46 4 2 4 4 1019 1059 1098 1137 1176 1215 1255 1294 1333 1372 1411 AK39 3 5 3 7 1212 1259 1305 1352 1399 1445 1492 1539 1585 1632 1678 AK32 3 3 2 1402 1455 1509 1563 1617 1671 1725 1779 1833 1887 1941 3 to 5 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 BX BELTS 2VP42 2 9 3 9 3 4 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 6 5 1 2 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 2BK160H 15 4 15 7 330 339 348 357 366 375 385 394 403 412 421 430 439 2BK140H 13 4 13 7 378 388 399 409 420 430 441 451 462 472 483 493 504 2BK120H 11 4 11 7 442 455 467 479 491 504 516 528 541 553 565 577 590 2BK110H 10 4 10 7 484 497 511 524 537 551 564 578 591 605 618 631 645 2BK100H 9 4 9 7 534 548 563 578 593 608 622 637 652 667 682 697 711 2BK90H 8 4 8 7 595 611 628 644 661 677 694 710 727 744 760 777 793 2BK80H 7 4 7 7 672 6
11. F 4 Remove the cap from the combination gas valve regulator adjustment size 1 3 or the cap from the MR212 valve size 4 5 Using the regulator pressure adjusting screw adjust the high fire manifold pressure to 5 in w c maximum for natural gas and 2 5 in w c maximum for propane gas High fire should be set to generate the desired temperature rise If the high fire screw is at the end of its adjustment and more pressure is needed then adjust the main building gas pressure regulator spring located external to the unit to achieve the proper manifold pressure Turning the regulator screw clockwise will increase pressure and counter clockwise will decrease pressure Remember The high fire DC voltage should read 12 VDC minimum and should typically be 15 VDC on the Flame Safety Controller test jacks 5 Reconnect the wire on the Maxitrol 14 amplifier at terminal 4 wires 2 and 4 for Maxitrol 44 6 The low fire manifold pressure must now be set Low fire can be achieved by removing the wire at terminal 5 from the Maxitrol 14 amplifier remove 8 for Maxitrol 44 Check the low fire flame signal to ensure that the DC voltage is 12 VDC minimum on the Flame Safety Controller test jacks 7 Using the bypass screw located on the side of the M511 and M611 valves and under the cap of the MR212 valve adjust low the low fire manifold pressure until there is a very thin flame along the entire length of the burner No dark spots should be seen in the
12. and all returned equipment shall be shipped by the BUYER freight prepaid to a destination determined by the MANUFACTURER 5 INSTALLATION It is imperative that this unit is installed and operated with the designed airflow gas and electrical supply in accordance with this manual If there are any questions about any items please call the service department at 1 866 784 6900 for warranty and technical support issues Mechanical WARNING DO NOT RAISE VENTILATOR BY THE INTAKE HOOD BLOWER OR MOTOR SHAFT OR BEARINGS USE LIFTING LUGS PROVIDED OR A SLING Site Preparation 1 Provide clearance around installation site to safely rig and lift equipment into its final position Supports must adequately support equipment Refer to manufacturer s estimated weights 2 Consider general service and installation space when locating unit 3 Locate unit close to the space it will serve to reduce long twisted duct runs 4 Do not allow air intake to face prevailing winds Support unit above ground or at roof level high enough to prevent precipitation from being drawn into its inlet The inlet must also be located at least 10 feet away from any exhaust vents The heater inlet shall be located in accordance with the applicable building code provisions for ventilation air All air to the heater must be ducted from the outdoors Recirculation of room air is not permitted If in doubt regarding the application consult the manufacturer Assembly Int
13. burner The burner may be observed through the view port located on the external wall of the heater Replace the cap to the Maxitrol valve and restore all of the original wiring on the Maxitrol amplifier and gas components 8 A final gas leak check shall be performed to verify the gas tightness of the heater s components and piping under normal operating conditions This can be done by measuring the gas pressure at the gas plug just downstream of the modulating valve 13 Adjust pilot flame Lock unit into high fire Adjust incoming gas pressure Does high fire produce at least a 70 F temp rise and produce the correct manifold pressure Adjust high fire No Lock unit into low fire Yes Does thin flame fill entire burner length Adjust low fire Setting incoming pressure Presure must be measured at first T in supply gas line before the first gas valve Adjusting the pilot The pilot DC signal should be 12 VDC minimum Adjusting high fire High fire manifold pressure should be 5 maximum for natural gas and 2 5 maximum for propane High fire should produce at least a 70 F temperature rise Remove wire 4 from the Maxitrol 14 amplifier 2 and 4 for Maxitrol 44 This will drive the valve into its full open position Adjust high fire with the regulator inside the unit Turn clockwise to increase temperature rise Ensure that DC flame signal is minimum 12 VDC Replace the wires on the Maxitro
14. or equivalent Motorized Intake Damper On units shipped with the optional motorized intake damper a power transformer is supplied with the unit if the main incoming voltage is greater than 120V The damper motor is automatically energized when the main disconnect switch is in the ON position No external wiring to the damper motor is required WARNING Disconnect power before installing or servicing fan High voltage electrical input is needed for this equipment This work should be performed by a qualified electrician 10 Remote Control Panel On units shipped with the optional remote control panel an electrical drop containing the panel wiring is provided with the heater There is a terminal strip inside the remote panel that matches the terminals in the heater unit The remote panel should be wired as shown below BL YW RD BK PK RD WH OR BR GY BK RD YW PK RD BK WH BK OR BR GY PK RD BK YW RD OR BR GY WH BK 1 E PK YW BK RD WH GY BR OR RD NC BK Fire System Microswitch BK NO PR C Fan to Building Wiring Connection 11 Pilot Assembly OPERATION Prior to starting up or operating the heater check all fasteners for tightness In particular check the set screw in the wheel hub bearings and the fan sheaves pulleys With power and gas to the heater OFF or prior to connecting ventilator to
15. power turn the fan wheel by hand to be sure it is not striking the inlet or any obstacles Re center if necessary Start Up Special Tools Required AC Voltage Meter Tachometer Standard Hand Tools Amperage Meter Manometer Differential Pressure Gauge Start Up Procedure 1 Check all electrical connections for tightness and continuity 2 Check pulley alignment and belt tension as described below 3 Inspect the condition of the intake damper and damper linkage if provided 4 Inspect the air stream for obstructions and install intake filters if missing 5 Compare the supplied motor voltage with the fan s nameplate motor voltage If this does not match correct the problem 6 Start the fan up by turning the external disconnect to the ON position and shut it OFF immediately to check rotation of the wheel with the directional arrow on the blower scroll Reversed rotation will result in poor air performance motor overloading and possible burnout For units equipped with a single phase motor check the motor wiring diagram to change rotation For 3 phase motors any two power leads can be interchanged to reverse motor direction 7 When the fan is started up observe the operation and check for any unusual noises Pilot Adjustment 1 Restart the fan and check the gas supply pressure at the inlet gas tap upstream of all electronic valves The inlet pressure should be 7 in 14 in w c 7 in w c 5
16. surfaces of this heater may not be installed less than 6 from combustible materials The heater base may be installed on combustible surfaces Allow 24 minimum service clearance on both sides of this heater 6 Recommended Supply Ductwork Sizes Blower Size Duct Size Straight Duct Length 10 14 x 14 48 in 12 16 x 16 54 in 15 20 x 20 72 in 18 24 x 24 86 in 20 26 x 26 108 in 25 32 x 32 168 in through vertical portion of the ventilator base assembly flange using a minimum of eight 8 lug screws anchor bolts or other suitable fasteners not furnished Shims may be required depending upon curb installation and roofing material Check all fasteners for tightness The diagrams below show different mechanical installation configurations Adequate building relief shall be provided so as to not over pressurize the building when the heating system is operating at its rated capacity This can be accomplished by taking into account through standard engineering methods the structure s designed infiltration rate by providing properly sized relief openings or by interlocking a powered exhaust system or by a combination of these methods Heaters installed with intake ductwork must be purged to replace at least four air changes of the volume of the intake duct If the failure or malfunction of this heater creates a hazard to other fuel burning equipment in the building e g when the heater is providing ma
17. 7 526 535 544 2B5V160 16 16 3 497 508 519 529 540 550 561 571 582 593 603 614 624 2B5V154 15 4 15 7 516 527 538 549 560 571 582 593 604 615 626 637 648 2B5V136 12 6 12 9 628 642 655 669 682 695 709 722 735 749 762 776 789 2B5V124 12 4 12 7 638 652 666 679 693 706 720 733 747 761 774 788 801 2B5V110 11 11 3 717 733 748 763 779 794 809 824 840 855 870 885 901 15 to 20 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 BX BELTS 2VP75 5 8 7 6 2 7 4 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 6 5 1 2 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 2B5V278 27 8 28 1 381 387 393 399 405 411 417 424 430 436 442 448 454 2B5V250 25 25 3 423 430 436 443 450 457 464 470 477 484 491 498 505 2B5V234 23 4 23 7 451 459 466 473 480 488 495 502 509 517 524 531 539 2B5V200 20 20 3 527 535 544 552 561 569 578 586 595 603 612 620 629 2B5V184 18 4 18 7 572 581 590 600 609 618 627 636 646 655 664 673 683 2B5V160 16 16 3 656 667 677 688 698 709 720 730 741 751 762 773 783 2B5V154 15 4 15 7 681 692 703 714 725 736 747 758 769 780 791 802 813 2B5V136 12 6 12 9 829 842 856 869 883 896 909 923 936 949 963 976 990 2HP Motors on 20 IN Blowers use 2VP42 Pulleys TURNS ON MOTOR PULLEY 10 20 IN BLOWER TURNS ON MOTOR PULLEY TURNS ON M
18. 78 27 8 28 1 184 189 194 200 205 210 215 220 225 230 235 240 246 2B5V250 25 25 3 205 210 216 222 227 233 239 244 250 256 261 267 273 2B5V234 23 4 23 7 218 224 230 237 243 249 255 261 267 273 279 285 291 2B5V200 20 20 3 255 262 269 276 283 290 297 304 312 319 326 333 340 2B5V184 18 4 18 7 277 284 292 300 307 315 323 331 338 346 354 361 369 2B5V160 16 16 3 317 326 335 344 353 362 370 379 388 397 406 414 423 2B5V154 15 4 15 7 330 339 348 357 366 375 385 394 403 412 421 430 439 2B5V136 12 6 12 9 401 412 423 435 446 457 468 479 490 501 513 524 535 2B5V124 12 4 12 7 407 419 430 441 453 464 475 487 498 509 521 532 543 2B5V110 11 11 3 458 471 483 496 509 522 534 547 560 572 585 598 611 7 1 2 to 10 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 BX BELTS 2VP60 4 3 5 5 4 7 5 9 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 6 5 1 2 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 2B5V278 27 8 28 1 289 295 301 307 313 319 325 331 338 344 350 356 362 2B5V250 25 25 3 320 327 334 341 348 355 361 368 375 382 389 395 402 2B5V234 23 4 23 7 342 349 357 364 371 378 386 393 400 408 415 422 429 2B5V200 20 20 3 399 408 416 425 433 442 450 459 467 476 484 493 501 2B5V184 18 4 18 7 434 443 452 461 470 480 489 498 507 51
19. 91 709 728 747 765 784 803 821 840 859 877 896 2BK70H 6 4 6 7 772 794 815 837 858 880 901 923 944 965 987 1008 1030 2BK60H 5 4 5 7 908 933 958 984 1009 1034 1059 1084 1110 1135 1160 1185 1211 2BK55H 4 9 5 2 995 1023 1050 1078 1106 1133 1161 1189 1216 1244 1272 1299 1327 2BK50H 4 4 4 7 1101 1132 1162 1193 1223 1254 1285 1315 1346 1376 1407 1438 1468 7 1 2 to 10 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 BX BELTS 2VP60 4 3 5 5 4 7 5 9 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 6 5 1 2 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 2BK160H 15 4 15 7 516 527 538 549 560 571 582 593 604 615 626 637 648 2BK140H 13 4 13 7 592 604 617 630 642 655 667 680 693 705 718 730 743 2BK120H 11 4 11 7 693 708 722 737 752 767 781 796 811 826 840 855 870 2BK110H 10 4 10 7 758 774 790 806 822 838 854 871 887 903 919 935 951 2BK100H 9 4 9 7 836 854 871 889 907 925 943 960 978 996 1014 1031 1049 2BK90H 8 4 8 7 932 952 972 991 1011 1031 1051 1071 1091 1110 1130 1150 1170 2BK80H 7 4 7 7 1053 1075 1098 1120 1143 1165 1187 1210 1232 1255 1277 1299 1322 3 to 5 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 BX BELTS 2VP42 2 9 3 9 3 4 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 6 5 1 2 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 2B5V2
20. Adjust to proper gas pressure Pilot valve is off Turn pilot valve on Pilot orifice fitting leak Tighten pilot orifice Excessive drafts Re direct draft away from unit Safety device has cut power Check limits and airflow switch Dirty flame sensor Clean flame sensor Remote panel in Vent mode Change to Heat mode No spark at igniter Check wiring sensor and ignition controller Check spark gap as shown below Main Burner Does Not Light Pilot is Lit Defective valve Replace combination valve Loose valve wiring Check wiring to valve Defective pilot sensor Replace pilot sensor Shut off valve closed Open shut off valve Defective flame safety controller Replace flame safety controller Pilot fails as main gas valves open and main gas begins to flow Plug the first burner port next to the pilot gas tube with burner cement Not Enough Heat Main gas pressure too low Increase main gas pressure do not exceed 14 in w c inlet pressure 5 psi on size 4 5 heater Too much airflow Decrease airflow if possible Burner undersized Check design conditions Gas controls not wired properly Check wiring Thermostat setting too low Increase thermostat setting Thermostat malfunction Check replace thermostat Unit locked into low fire Check wiring Too Much Heat Defective modulating gas valve Check replace modulating valve Thermostat setting too high Decrease thermostat setting Unit locked int
21. May 2008 Rev 11 FOR YOUR SAFETY The use and storage of gasoline or other flammable vapors and liquids in open containers in the vicinity of this appliance is hazardous Standard and Modular Direct Fired Heaters Installation Operation and Maintenance Manual Modular Direct Fired Heater Standard Direct Fired Heater Direct Fired Module Save these instructions This document is the property of the owner of this equipment and is required for future maintenance Leave this document with the owner when installation or service is complete RECEIVING AND INSPECTION Upon receiving unit check for any interior and exterior damage and if found report it immediately to the carrier Also check that all accessory items are accounted for and are damage free Turn the blower wheel by hand to verify free rotation and check the damper if supplied for free operation WARNING Improper installation adjustment alteration service or maintenance can cause property damage injury or death Read the installation operating and maintenance instructions thoroughly before installing or servicing this equipment ALWAYS disconnect power and gas prior to working on heater FOR YOUR SAFETY If you smell gas 1 Open windows 2 Don t touch electrical switches 3 Extinguish any open flames 4 Immediately call your gas supplier 3 TABLE OF CONTENTS WARRANTY
22. OTOR PULLEY TURNS ON MOTOR PULLEY TURNS ON MOTOR PULLEY 25 IN BLOWER TURNS ON MOTOR PULLEY TURNS ON MOTOR PULLEY 16 Flame Safety Controller Air Flow Switch DC Flame Signal DC Voltage Flame Status 0 to 5 VDC No Flame 6 to 11 VDC Weak Flame 12 to 18 VDC Strong Flame Sequence of Operation The direct fired heater is most easily understood when broken down into smaller individual systems There are two main systems a make up air fan and a heater The make up air fan consists of a blower and motor The heater may be further broken down into two control systems the Flame Safety Control FSC and the Modulating Gas System MGS The burner mixes air with the gas Natural or LP which heats the air Flame Safety Control The first system to understand is the Flame Safety Control The FSC is there only to monitor the flame NOT to control temperature The FSC uses a flame rectification sensor mounted on the pilot assembly to detect the presence of flame in the burner Flame strength and presence can be measured at the FSC by reading the rectified flame signal This is done by using a DC voltage meter attached to the test jacks on the top of the control Flame is present when the DC voltage reads between 6 and 18 VDC Ideal flame intensity produces a signal of 12 VDC or greater The FSC is also wired into an airflow switch which tells it whether there is proper airflow through the unit not just any airflow but pro
23. akes and curbs are shipped unassembled Upon unit arrival follow the following procedure to assemble the intake to the heater 1 Apply silicone or weather proof gasket on the back side of the flanges of the intake hood or v bank intake 2 Screw the flanges of the intake hood or v bank to the unit with the supplied sheet metal screws If the unit is a modular unit with a v bank or evaporative cooler section the v bank or evaporative cooler will bolt to the heater with the bolts provided Curb and Ductwork This fan was specified for a specific CFM and static pressure The ductwork attached to this unit will significantly affect the airflow performance Flexible ductwork and square elbows should not be used Also transitions and turns in ductwork near the fan outlet will cause system effect and will drastically increase the static pressure and reduce airflow The chart below shows the minimum fan outlet duct sizes and straight lengths recommended for optimal fan performance Follow SMACNA guides and recommendations for the remaining duct run Fans designed for rooftop installation should be installed on a prefabricated or factory built roof curb Follow curb manufacturer s instructions for proper curb installation The unit should be installed on a curb and or rail elevated not less than 20 above any surface Be sure duct connection and fan outlet are properly aligned and sealed Secure fan to curb CLEARANCES The top back and front
24. as supply when the unit is operating at maximum gas flow If the gas supply exceeds 14 in w c 5 psi for sizes 4 5 housings it will damage the internal valve components and if it is below 7 in w c the heater may not perform to specifications NOTICE Refer to the heater rating plate for determining the minimum gas supply pressure for obtaining the maximum gas capacity for which this heater is specified 9 Copper Wire Ampacity Wire Size AWG Maximum Amps 14 20 12 25 10 30 8 40 6 55 4 70 Electrical Before connecting power to the heater read and understand this entire section of this document As built wiring diagrams are furnished with each fan by the factory and are attached to the door of the unit Electrical wiring and connections should be done in accordance with local ordnances and the National Electric Code ANSI NFPA70 Be sure the voltage and phase of the power supply and the wire amperage capacity is in accordance with the motor nameplate For additional safety information refer to AMCA publication 410 96 Recommended Safety Practices for Users and Installers of Industrial and Commercial Fans 1 Always disconnect power before working on or near a heater Lock and tag the disconnect switch or breaker to prevent accidental power up 2 An electrical drop containing the motor power wiring is shipped with every fan The electrical drop should be brought through one of the condu
25. axitrol gas valve to provide discharge air to match the selected temperature on the temperature selector The Maxitrol 44 utilizes a room temperature sensor to control room temperature as well as a discharge air sensor in order to control the discharge air temperature The modulating gas valve controls the amount of gas flow to the burner based on the temperature rise needed When the modulating gas valve is all the way open and achieving the maximum BTUs and temperature rise of the unit it is called high fire High Temperature Limit One of the back up safety device is the high temperature limit switch This switch is a mechanical thermostat that measures the temperature inside the unit downstream of the burner If the factory set temperature of 170 F is exceeded it will signal the FSC to turn off the burner This requires a manual reset of the high temperature limit This insures that the discharge does not exceed 185 F Operation Summary With the blower already running and the airflow switch proven The outside air temperature falls below the setting of intake air thermostat or The optional remote panel is set to Manual and Heat mode The FSC in energized and the following occurs FSC indicates that it has power by illuminating the OPR CTRL LED FSC verifies proper Airflow 18 Begins Pilot Trial For Ignition and turns on PTFI LED The pilot gas solenoid valve is opened the spark igniter begins sparking and the flamero
26. d sensor watches for flame initiation When flame is established the FLAME LED is illuminated and main valve opens and the FSC powers the Maxitrol system and gas flow begins modulating The FSC monitors the flame while the Maxitrol system adjusts to the selected temperature The Maxitrol system checks the discharge air temperature and the room temperature for the Maxitrol 44 and regulates the gas going to the burner to satisfy the temperature setting The Maxitrol system will modulate the main burner gas from 100 down to 5 as needed Optional Remote Panel Circuit Power Supply From Heater Power Light On Off No Power to Panel Panel is Powered Blower Switch Nothing Happens No Power is Sent to Heater Power is Sent to Heater to Open Damper if provided and Start Blower Off Position 3 Position Panels Only Manual Blower On Light Damper is not Open or Freeze Stat has Detected Low Temperature Operation On Off Temperature Control Switch Blower Operates Heat Does not Operate Vent Position Heat Position Heat Circuit is Energized Burner On Light Illuminates with proper flame Flame Failure Light illuminates if proper flame is not established Blower Operates Cooling Circuit is Energized Cool Position if provided Power is Sent to Heater to Open Damper if provided and Start Blower Blower On Light Damper is not Open or Freeze Sta
27. d when the Flame Safety Control is in Alarm mode CLOGGED FILTER Optional Illuminated when the Intake Filters are Dirty 4 Temperature Control Controls the discharge temperature of a standard unit The temperature dial is replaced with Maxitrol Selectrastat in Space Heating applications and is used to control the space temperature 1 2 3 4 CLOGGED FILTER FLAME FAILURE 21 Troubleshooting The following tables list causes and corrective actions for possible problems with direct fired heater units Review these lists prior to consulting manufacturer Airflow Troubleshooting Chart Problem Potential Cause Corrective Action Fan Inoperative Blown fuse or open circuit breaker Replace fuse or reset circuit breaker and check amps Disconnect switch in Off position Turn to On position Motor wired incorrectly Check motor wiring to wiring diagram located on fan motor Broken fan belt Replace belt Motor starter overloaded Reset starter and check amps Remote panel set to Off Position Set Remote Panel to Manual or Auto Position Motor Overload Fan rotating in the wrong direction Be sure fan is rotating in the direction shown on rotation label Fan speed is too high Reduce fan RPM Motor wired incorrectly Check motor wiring to wiring diagram located on fan motor Overload in starter set too low Set overload to motor FLA value Motor HP too low Determine if HP is suffic
28. ecycle for heat until it has been properly reset Anytime the FSC has gone into Alarm mode the problem must be diagnosed and corrected to avoid future lockouts after resetting To begin troubleshooting or to reset the FSC shut down power to the heater and restart the heater This will clear the alarm from the flame safety Air Flow Switch There are both high and low airflow switches contained within one housing measuring the pressure drop across the burner This is to insure that there is proper airflow 15 in w c to 80 in w c across the burner and proper combustion at all times Both switches are wired in series and have single pole double throw one common contact one normally open contact and one normally closed contact switches that are switched by air pressure There are two airflow tubes in the heater located near the burner and profile plate assembly profile plates surround the burner and control air into the burner section In the case of clogged filters blocked intake excessive duct static pressure or a broken belt the correct burner differential pressure may not be achieved not allowing the low 17 Maxitrol 14 Amplifier High Temperature Limit airflow switch to close The high airflow switch protects against profile plate failures that cause excessive airflow through the burner In the event that the pressure drop across the burner is not in the range of the airflow switch gas flow to the burner is sto
29. ient for job Duct static pressure lower than design Reduce fan RPM Insufficient Airflow Fan rotating in the wrong direction Be sure fan is rotating in the direction shown on rotation label Poor outlet conditions There should be a straight clear duct at the outlet Intake damper not fully open Inspect damper linkage and replace damper motor if needed Duct static pressure higher than design Improve ductwork to eliminate or reduce duct losses Blower speed too low Increase fan RPM Do not overload motor Supply grills or registers closed Open and adjust Dirty or clogged filters Clean and or replace Belt slippage Adjust belt tension Excessive Airflow Blower speed to high Reduce fan RPM Filters not installed Install filters Duct static pressure lower than design Reduce fan RPM Excessive Vibration and Noise Misaligned pulleys Align pulleys Damaged or unbalanced wheel Replace wheel Fan is operating in the unstable region of the fan curve Refer to performance curve for fan Bearings need lubrication or replacement Lubricate or replace Fan speed is too high Reduce fan RPM Belts too loose worn or oily Inspect and replace if needed 22 Burner Troubleshooting Chart Problem Potential Cause Corrective Action Pilot Does Not Light Stay Lit Main gas if off Open main gas valve Air in gas line Purge gas line Dirt in pilot orifice Clean orifice with compressed air Gas pressure out of range
30. it openings located in the base of the unit run through the curb and connected to a junction box inside the building 3 A dedicated branch circuit should supply the motor circuit with short circuit protection according to the National Electric Code This dedicated branch should be run to the junction box mentioned above and connected as shown in a following illustration labeled Fan to Building Wiring Connection 4 Make certain that the power source is compatible with the requirements of your equipment The heater nameplate identifies the proper phase and voltage of the motor 5 Units shipped with an optional remote panel have two electrical circuit drops It is important to run the motor wires in a separate conduit from the remote control wiring The DC wires from the unit temperature controller located in the control drop should either be shielded cable or be run in a separate conduit 6 Before connecting heater to the building power source verify power line wiring is de energized 7 Secure the power cables to prevent contact with sharp objects 8 Do not kink power cable and never allow the cable to come in contact with oil grease hot surfaces or chemicals 9 Before powering up the heater check fan wheel for free rotation and make sure that the interior of the heater is free of loose debris or shipping materials 10 If any of the original wire supplied with the heater must be replaced it must be replaced with type TW wire
31. ke up air to a boiler room the unit is to be interlocked to open inlet air dampers or other such devices Units being installed in airplane hangars should be installed in accordance with the Standard for Aircraft Hangars ANSI NFPA 409 Units being installed in public garages should be installed in accordance with the Standard for Parking Structures ANSI NFPA 88A or the Standard for Repair Garages ANSI NFPA 88B and with CAN CGA B149 Installation Codes Roof Mount Installation Installation with Exhaust Fan 7 Direct Fired Module Installation Indoor INLINE Installation Heat Module Add On Installation Modular heat units shipped to add heat onto existing blower only applications require field mechanical and wiring installation 1 Remove existing filter intake and lifting lugs from blower section intake side 2 Attach heat module to blower intake using the provided sheet metal screws and bolts Tighten screws and bolts securely to compress the gasket between the heat module and the blower module 3 Support and level the end of the heat module end opposite the blower with the provided equipment legs rails 4 Attach the filter hood to the intake side of the heater module 5 Drill a hole in the discharge of the blower large enough to insert the Maxitrol mixing tube and discharge sensor if provided Install the Maxitrol mixing tube in the proper airflow direction The airflow direction is labeled on the Maxitrol mixing tube
32. l Amplifier Adjusting low fire Remove wire 5 from the Maxitrol 14 amplifier 8 for Maxitrol 44 This will drive the valve into its lowest position Adjust the low fire by turning the low fire bypass screw on the side of teh modulating valve for M511 and M611 models For MR212 valves the low and high fire are both under the valve cover Refer to the included Maxitrol literature for more detailed information Ensure that DC flame signal is minimum 12 VDC and that the enite length of burner is filled with a thin flame Yes No No Burner start up complete Yes Is incoming gas pressure 7 14 7 5 psi for size 4 5 units Heater Start Up Summary 14 Maximum RPM and HP Chart Blower Size Maximum RPM Maximum HP 10 1800 2 12 1500 3 15 1400 5 18 1200 5 20 1000 10 25 900 20 Pulley Adjustment Illustration Pulley Setscrew Torque Thread Size Torque IN Lb No 10 bushing 32 1 4 bushing 72 5 16 130 Final Start Up Procedure 1 With the air and burner systems in full operation and all ducts attached measure the system airflow Motor sheave pulley is variable pitch and allows for an increase or decrease of the fan RPM to adjust the airflow as shown in the illustration below For your convenience a RPM chart is included in the following pages 2 Once the proper airflow is achieved measure and record the fan speed with a reliable tachomete
33. ms between the wires Replace the Temperature Selector Is there a short or open circuit in Modulating Valve Should be 45 55 Ohms 60 80 on MR212 Replace Modulating Valve No No No No No Yes Yes Yes Yes Yes No Burner lights but heater stays in High Fire Is there a jumper between terminals 2 amp 3 on the Maxitrol Amplifier Install Jumper Is there a short circuit in the Remote Temperature Selector or wiring Repair short or replace Temperature Selector Is there an open circuit in the Discharge Air Sensor or wiring Repair Circuit or replace the Discharge Air Sensor Is Plunger in the Modulating Valve jammed Inspect and clean It should operate freely in the sleeve Foreign object holding valve open Remove bottom plate and inspect valve and seat Clean or replace valve No No No No Yes Yes Yes Troubleshooting Flowcharts 25 MAINTENANCE To guarantee trouble free operation of this heater the manufacturer suggests following these guidelines Most problems associated with fan failures are directly related to poor service and maintenance Please record any maintenance or service performed on this fan in the documentation section located at the end of this manual WARNING DO NOT ATTEMPT MAINTENANCE ON THE HEATER UNTIL THE ELECTRICAL SUPPLY HAS BEEN COMPLETELY DISCONNECTED AND THE MAIN GAS SUPPLY VALVE HAS BEEN TURNED OFF General Maintenance
34. n burner with a wire brush and insure burner ports are free of debris Then wipe the burner with a clean rag 27 May 2008 Rev 11 28 Start Up and Maintenance Documentation START UP AND MEASUREMENTS SHOULD BE PERFORMED AFTER THE SYSTEM HAS BEEN AIR BALANCED AND WITH THE HEAT ON Warranty will be void without completion of this form Job Information Job Name Service Company Address Address City City State State Zip Zip Phone Number Phone Number Fax Number Fax Number Contact Contact Purchase Date Start Up Date Heater Information Refer to the start up procedure in this manual to complete this section Name Plate and Unit Information Field Measured Information Model Number Motor Voltage Serial Number Motor Amperage Motor Volts RPM Motor Hertz Burner Differential Pressure in w c Motor Phase Pilot Flame Signal VDC Motor FLA Low Fire Flame Signal VDC Motor HP High Fire Flame Signal VDC Blower Pulley Gas Type Motor Pulley High Fire Inlet Gas Pressure in w c Belt Number Low Fire Manifold Gas Pressure in w c Gas Type High Fire Manifold Gas Pressure in w c Min Btu Hr Thermostat Set Point Max Btu Hr Temperature Control Discharge Space Airflow Direction Correct Incorrect If measured amps exceed the FLA rating on the nameplate fan RPM must be reduced to decrease the measured amps below the nameplate FLA rating Maintenance Record Date Se
35. nt spikes 12 Terminal Strip Central location to terminate control wiring Should be used for troubleshooting 13 Control Transformer 120V primary 24V secondary control transformer 14 Low Pressure Airflow Probe Measures profile pressure downstream of burner 15 High Pressure Airflow Probe Measures profile pressure upstream of burner 16 Modulating Gas Valve Modulates gas flow to burner to provide proper air temperature 17 Manifold Gas Pressure Tap Manifold gas pressure should be measured here 18 Flame Safety Control Initiates and monitors flame 19 Airflow Switch A safety device insuring proper air flow during burner operation 20 Ignition Transformer Produces high voltage spark to ignite flame 21 Intake Air Thermostat De energize heating circuit when intake air exceeds set point 22 Damper Actuator Motor containing end switch that opens intake damper 23 Manual Gas Shut Off Valve Allows gas flow to burner to be shut off to leak test gas train 4 3 2 8 10 15 5 16 20 22 23 12 14 19 18 6 9 21 13 5 7 6 17 1 11 20 Remote Panel Option The Remote Panel is a device used to control the operation of the heater from a remote location This unit is available in both a 2 Position or 3 Position configuration and with or without a cooling output It also will accommodate both the Maxitrol discharge temperature dial and the Maxit
36. o high fire Check wiring Thermostat wired incorrectly Check thermostat wiring Proper Spark Gap 23 Remote Panel Troubleshooting Chart Light Indication Condition Possible Cause No Lights Power not available to Remote Panel Bad voltage to unit Main disconnect in OFF Position Circuit breaker tripped Bad main transformer POWER Light Only Proper unit Off Operation No problem No power to motor starter Manual Off Auto Switch in Off Position 3 Position Remote Panels Only Improper damper function Low Temperature Thermostat Timed Out Option POWER Light and BLOWER ON Light Proper Ventilation Operation No Problem No Power to Flame Safety Controller Manual Off Auto Switch in Off Position 2 Position Remote Panels Only Heat Vent Switch in Vent Position Gas Pressure Switch Tripped option High Temperature Limit Thermostat Tripped Manual Off Auto Switch in Auto Position and Intake Air Thermostat not Satisfied Improper Airflow Insufficient Airflow Excessive Airflow Bad airflow switch Problem with air probes Problem with airflow tubing Broken Belt POWER Light and BLOWER ON Light and BURNER ON Light Proper Heating Operation No Problem CLOGGED FILTER Light On Optional Filters Clogged Filters Dirty or Need Replacement FLAME FAILURE Light On Flame Safety Alarm Activated No Flame Detected during Pilot Establishment Period Combination Valve in Off Position Unit Si
37. o the OFF position 2 CLOSE the inlet gas valve located on the heater To re start the unit the following steps should be done 1 Turn the external disconnect switch to the ON position 2 OPEN the inlet gas valve located on the heater 26 Burner Orifice Drill Size Orifice Drill Size Gas Port 31 Air Port 43 2 weeks after startup 1 Belt tension should be checked after the first 2 weeks of fan operation Belts tend to stretch and settle into pulleys after an initial start up sequence Do not tension belts by changing the setting of the motor pulley this will change the fan speed and may damage the motor To re tension belts turn the power to the fan motor OFF Loosen the fasteners that hold the blower scroll plate to the blower Rotate the motor to the left or right to adjust the belt tension Belt tension should be adjusted to allow 1 64 of deflection per inch of belt span Exercise extreme care when adjusting V belts as not to misalign pulleys Any misalignment will cause a sharp reduction in belt life and produce squeaky noises Over tightening will cause excessive belt and bearing wear as well as noise Too little tension will cause slippage at startup and uneven wear Whenever belts are removed or installed never force belts over pulleys without loosening motor first to relieve belt tension When replacing belts use the same type as supplied by the manufacturer On units shipped with double groove pulleys matched bel
38. pacities 3 The incoming pipe near the heater should be sized to match the connection on the outside of the unit Unit inlet sizes are shown in the table to the right Avoid multiple taps in the gas supply so the unit has a steady supply of gas at all times 4 Install a ground joint union with brass seat and a manual shut off valve external to the unit casing as shown below adjacent to the unit for emergency shut off and easy servicing of controls 5 Provide a sediment trap as shown below before each unit and where low spots in the pipe line cannot be avoided 6 Blow out the gas line to remove debris before making connections Purge line to remove air before attempting to start unit Purging of air from gas lines should be performed as described in ANSI Z223 1 latest edition National Fuel Gas Code or in Canada in CAN CGA B149 7 All field gas piping must be pressure leak tested prior to unit operation Use a non corrosive bubble forming solution or equivalent for leak testing The heater and its individual shut off valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of psi The heater must be isolated from the gas supply piping system by closing its individual manual shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or less than psi 8 This unit requires a constant 7 in w c minimum natural g
39. per airflow Proper airflow occurs when there is a 15 in w c to 80 in w c differential pressure drop across the burner When the airflow through the heater produces a pressure drop in this range the FSC indicates so by illuminating the AIRFLOW LED The FSC controls the opening of the redundant solenoid gas valves and the operation of the spark igniter to initiate a pilot flame upon start up The OPR CTRL LED indicates that there is power to the FSC Next the AIRFLOW LED will come on if there is proper airflow through the unit Third the unit will pause to purge any gasses or combustible vapors before attempting flame ignition Then there is a Pilot Trial For Ignition PTFI and the PTFI LED comes on During PTFI the FSC opens the pilot gas valve and allows gas to flow to the pilot assembly At the same moment the spark igniter is started causing the spark to ignite the pilot gas When the flamerod sensor detects the flame it turns on the FLAME LED turns off the PTFI LED and powers the modulating gas system This is the normal operating mode The FSC continues to monitor the flame and airflow Once this occurs the unit is in a main flame cycle and thus powers the main gas valve and the modulating gas system This is the normal operating mode The FSC continues to monitor the flame and airflow The last LED on the FSC is the ALARM LED This will turn on when the FSC determines an unsafe condition has occurred and will not allow the unit to r
40. pped by the Flame Safety Control The graphs below illustrate the approximate cfm going through the unit vs the differential pressure measured by the airflow switch Simply measure the differential profile pressure drop at the airflow tubes in the unit and match that value up to the matching unit curve below This will show the cfms traveling through the burner and will indicate proper airflow or airflow problems too much or not enough If the pressure drop is outside of the 15 to 80 range the blower rpm should be adjusted to fix airflow Size 1 3 Heater CFM vs Burner Profile Pressure 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 0 15 0 2 0 25 0 3 0 35 0 4 0 45 0 5 0 55 0 6 0 65 Burner Differential Profile Pressure in w c CFM Size 1 Size 2 Size 3 Size 4 5 Heater CFM vs Burner Profile Pressure 3000 5000 7000 9000 11000 13000 15000 17000 19000 21000 23000 25000 0 15 0 2 0 25 0 3 0 35 0 4 0 45 0 5 0 55 0 6 0 65 Burner Differential Profile Pressure in w c CFM Size 4 Size 5 Modulating Gas System The second system the Maxitrol modulating gas system consists of a temperature selector dial a discharge air sensor an amplifier and a modulating gas valve The two types of Maxitrol systems used are the Maxitrol 14 series or the Maxitrol 44 series The Maxitrol 14 utilizes a discharge air sensor and modulates the M
41. psi on Size 4 5 heaters If the inlet pressure is too high install an additional pressure regulator external to the unit 2 Open the field installed manual gas shut off valve and the manual main gas valve on the combination gas control valve 3 Call for heat with the intake air thermostat turn set point to temperature above outside air and allow the pilot to light If the pilot does not light purge the pilot line If air purging is required disconnect the pilot line at the outlet of the pilot valve 4 Check the pilot flame voltage at the Flame Safety Control interface test jacks A weak pilot flame can be caused by low gas pressure or a dirty pilot orifice To adjust the pilot flame remove the cap from the pilot adjustment screw on the combination gas valve Increase the pilot gas flow by turning the screw counter clockwise Decrease the pilot gas flow by turning the screw clockwise The pilot DC voltage should read 12 VDC minimum and should typically be 15 VDC 5 Once the pilot has been established open the main manual gas shut off valve downstream of the electronic valves Check to make sure that the main gas valve opens and gas flows to the burner 12 Maxitrol M511 and M611 Low Fire Bypass Screw Mod Valve Voltage Summary Volts DC Firing Mode 0 to 5 VDC Low Fire 5 to 15 VDC Modulation 15 to 20 VDC High Fire Maxitrol MR212 Low Fire Bypass Screw Average Manifold Pressure vs Firing Rate Ft of Burner 1 00
42. r Caution Excessive speed will result in motor overloading or bearing failure Do not set fan RPMs higher than specified in the maximum RPM chart See the troubleshooting guide for more information 3 Measure and record the voltage and amperage to the motor and compare with the motor nameplate to determine if the motor is operating under safe load condition 4 Once the rpm of the ventilator has been properly set disconnect power and recheck belt tension and pulley alignment as described below Pulley Adjustment The adjustable motor pulley is factory set for the RPM specified Speed can be increased by closing or decreased by opening the adjustable motor sheave Two groove variable pitch pulleys must be adjusted an equal number of turns open or closed Any increase in speed represents a substantial increase in horsepower required by the unit Motor amperage should always be checked to avoid serious damage to the motor when the speed is varied Always torque setscrews according to the setscrew torque chart Pulley Alignment Proper Belt Tension 15 Pulley Combination Chart Motor RPM 1725 1 3 to 1 1 2 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 AX BELTS 1VL34 1 9 2 9 2 3 Open Closed BLOWER PULLEY DATUM DIAMETER PITCH DIAMETER 5 4 1 2 4 3 1 2 3 2 1 2 2 1 1 2 1 1 2 0 AK114 11 11 2 308 323 339 354 370 385 400 416 431 447 462 1 3 to 2 HP MOTOR PULLEY Dd1 Dd2 Pd1 Pd2 AX BELTS 1VL40 2 4 3 4 2
43. rol space sensing Selectrastat It is important to understand the following Remote Panel controls and uses 1 Manual Off Auto Switch Used to control blower operation and tempering mode of unit The AUTO position allows the unit to decide through the use of the intake air thermostat whether or not heating is needed The MANUAL position allows the user to control whether or not heat is needed The OFF position will turn the blower off when a 3 Position remote panel is ordered The OFF position will disable all temperature controls when a 2 Position remote panel is ordered and fan power is then controlled by the pre wire package only 2 Heat Vent Switch This switch is powered when the Manual Off Auto switch is in the MANUAL position It is used to control the tempering mode of the unit The VENT position will prevent the burner from operating and the heater will deliver untempered air The HEAT position will force the burner on and the unit will heat the incoming air This switch becomes a Heat Vent Cool switch when the cooling interlock is ordered This option provides a 120V cooling output from the remote panel 3 Lights Displays the current status of unit features The light definitions are as follows POWER Illuminated when there is power to Remote Panel BLOWER ON Illuminated when the blower motor is powered BURNER ON Illuminates after pilot flame has established and main valve is powered FLAME FAILURE Illuminate
44. rvice Performed Factory Service Department Phone 1 866 784 6900 Fax 1 919 554 9374 Maxitrol 14 amplifier Airflow Switch
45. t has Detected Low Temperature Operation On Off Intake Air Thermstat is Powered Intake Air is Cooler Than Thermostat Set Point Nothing Happens Intake Air is Warmer Than Thermostat Set Point Auto Heat Circuit is Energized Burner On Light Illuminates with proper flame Flame Failure Light illuminates if proper flame is not established 19 Components The following image and list outlines the typical direct fired heater components and their functions 1 Gas Inlet Main gas supply connection 2 Motor Starter Contactor with overload protection to start and protect motor 3 Freeze Stat Thermostat Optional De energizes blower motor if the discharge air temperature falls below the set point 4 Cooling Interlock Relay Optional Energizes power to cooling circuit on call for cooling 5 Inlet Gas Pressure Tap Inlet gas pressure should be measured here 6 Combination Gas Valve A combination of redundant solenoid valves pilot valve and gas regulator built into one unit 7 Pilot Tubing Pilot tube connection to combination gas valve 8 Manual Reset High Temperature Limit Safety device that prevents the heater from overheating 9 Maxitrol Modulating Amplifier Regulates temperature by modulating gas valve 10 Power Transformer Installed when motor voltage gt 120V Used to provide 120V service to controls 11 Circuit Breaker Protects electrical components from high curre
46. ts should always be used 2 All fasteners should be checked for tightness each time maintenance checks are preformed prior to restarting unit Every 3 months 1 Belt tension should be checked quarterly See instructions in the previous maintenance section Over tightening will cause excessive bearing wear and noise Too little tension will cause slippage at startup and uneven wear 2 Filters need to be cleaned and or replaced quarterly and more often in severe conditions Washable filters can be washed in warm soapy water When re installing filters be sure to install with the airflow in the correct direction as indicated on the filter Filter Quantity Chart Intake 16 x 20 20 x 25 Size 1 Sloped 3 Size 2 Sloped 3 Size 3 Sloped 6 Size 4 Sloped 10 Size 5 Sloped 8 Size 1 V Bank 3 Size 2 V Bank 8 Size 3 V Bank 8 Size 4 V Bank 15 Size 5 V Bank 12 Yearly 1 Inspect bearings for wear and deterioration Replace if necessary 2 Inspect belt wear and replace torn or worn belts 3 Inspect bolts and set screws for tightness Tighten as necessary 4 Inspect motor for cleanliness Clean exterior surfaces only Remove dust and grease from the motor housing to ensure proper motor cooling Remove dirt and grease from the wheel and housing to prevent imbalance and damage 5 Check for gas leaks and repair if present 6 Clean flame sensor by rubbing with steel wool to remove any rust build up 7 Clea
47. zes 1 3 Stuck Closed Gas Valve No or Low Gas Pressure Bad Spark Electrode Bad Ignition Transformer Flames Sensor Malfunction Clogged Pilot Orifices 24 Is Freeze Stat open Adjust or Replace Is end switch on Motorized Damper closed Adjust or Replace actuator YES YES NO Nothing Happens Is Overload tripped on starter Reset amp measure FLA of motor Is it higher than rating Adjust or change Pulley NO NO YES Blower runs but there is no heat Is the air flow LED on Flame Saftey illuminated Adjust pulley to achieve proper airflow NO Is outside air cooler than intake air thermostat setting Proper economizer operation YES NO Is High Temp Limit Tripped Reset Is there a Remote Panel Installed Check wiring Is Remote set to Heat Set Remote Panel to Manual and Heat mode Refer to Flame Safety Guide YES YES YES YES NO NO NO Burner lights but heater stays in Low Fire Is there voltage on Terminal 17 Replace FSC Are all valves powered and open Check valve wiring or open valves With wires 3 amp 4 removed from the Maxitrol Amplifier is there 9 5K to 11K Ohms between the wires Replace Discharge Air Sensor Remove Terminal 4 from the Maxitrol Amplifier Does the heater go into High Fire Replace Amplifier With wires 1 amp 2 removed from the Maxitrol Amplifier is there 9 5K to 11K Oh
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