Installation and Maintenance Manual
Contents
1. PENTAIR Raychem nstallation and Maintenance Manual SELF REGULATING AND POWER LIMITING HEATING CABLE SYSTEMS INDUSTRIAL HEAT TRACING SOLUTIONS EN RaychemSelfRegCable IM DOC71 Rev18 1 General information Pg 1 Heating cable selection Pa 3 3 Heating cable installation Pg 4 A Components installation Pg 13 5 Thermostats Pg 19 6 Thermal insulation and marking Pg 19 7 Power supply and electrical protection Pg 21 8 Heating cable testing Pg 21 9 Operation maintenance and pipe repairs Pg 23 1 0 Heating cable damage Pg 24 1 1 Troubleshooting guide Pg 24 1 GENERAL INFORMATION Use of the manual The Installation and Maintenance manual is for Raychem self regulating and power limiting heating cable systems on thermally insulated pipes and vessels only For information regarding other applications contact your Pentair representative BTV QTVR KTV amp XTV Self Regulating Heating Cables Colder Warmer Section Section W Power output varies with temperature As pipe temperature increases power output decreases At high temperatures the polymer expands reducing the number of the conductive paths and thus reducing current flow At low temperatures there are many conductive paths allowing current to flow between the conductors VPL Power Limiting Heating Cables dee HOT Conductor Node Connect2. 230 C 230 C OVPL4 CT 205 C 205 C 5VPL4 CT 160 C 160 C 20VPL4 CT 150 C 150 C B Warning As with any electrical equipment or wiring installation operating at line voltages heating cable and component damage or incorrect installation that allows the penetration of moisture or contamination can lead to electrical tracking arcing and potential fire hazard Do not connect heating cable conductors together or this will result in a short circuit Any unconnected heating cable end must be sealed with a Pentair approved end seal To prevent fire or explosion in hazardous areas verify that the maximum sheath temperature of the heating cable is below the auto ignition temperature of the gases in the area For further information see design documentation 2 HEATING CABLE SELECTION Check the design specification to make sure the proper heating cable is installed on each pipe or vessel Refer to Pentair product literature and the TraceCalc software to select the proper heating cable for each thermal chemical electrical and mechanical environment 3 HEATING CABLE INSTALLATION 3 1 Heating cable storage v 3 2 Store the heating cable in a clean dry place Temperature range 40 C to 60 C Protect the heating cable from mechanical damage Pre installation checks Check materials received LA Review the heating cable design and compare the list
3. Pipe length Glass cloth tape Pipe typical Hm Apply glass cloth tape before Wrap loops Tape after spiralling direction cable on pipe in opposite spiralling cable on pipe Heating cable length Heating cable length pipe length x spiral ratio Refer to design specification for spiral ratio Step 1 Make starting loop as shown Step 2 Grasp loop and wind around pipe Step3 Space evenly and attach to pipe Thermally insulate and weatherproof to specification Figure 2b Glass cloth tape typical Pitch 7 Heating cable Refer to design specification for spiral pitch Mark the pipe at the spiral pitch or use a simple length gauge Fix the heating cable as installation progresses Thermally insulate and weatherproof to specification 3 5 Cutting the heating cable 4 Cut the heating cable to length after it is attached to the pipe Before cutting it confirm the tracing allowance as per Sections 3 3 and 3 6 gt Raychem heating cable can be cut to length without affecting the heat output per metre 3 6 Typical installation details We Typical installation details for fixing heating cable to pipe fittings are shown hereafter General notes Trace pipe fittings as shown to allow easy maintenance ue Consult the design specification or Pentair product literature or TraceCalc software for the tracing requirements for fittings and supports gt Follow the recommendations for cutting and stripping
4. and PE Freeze protection systems should be meggered before the winter months each year see section 8 Temperature maintenance systems should be tested at least twice a year Function testing of electrical protection and temperature control systems should be carried out at regular intervals The Periodic Inspection Record on the following pages should be filled out during maintenance of each circuit in your system Piping systems repair and maintenance Isolate heating cable circuit Protect the heating cable from mechanical or thermal damage during pipe repair work Check heating cable installation after pipe repairs and restore thermal insulation following the recommendations in Section 6 Check correct functioning of electrical protection systems 23 10 11 HEATING CABLE DAMAGE Do not repair damaged heating cable Remove entire damaged section and splice in a new length using the appropriate Raychem splice kits Replace damaged heating cable at once Damage allowing moisture and contamination to enter the heating cable may result in arcing earth faults and potential fire hazards Heating cable exposed to fire or flame may cause further fire damage if powered Remove from service at once and replace before re use TROUBLESHOOTING GUIDE Refer to the Troubleshooting guide on pages 28 31 If the problem persists after following the guide procedures contact your Pentair representative immediately SLNAWWO
5. tips yy Use a reel holder that pays out smoothly with little tension Keep heating cable strung loosely but close to the pipe being traced to avoid interference with supports and equipment Pay out designed length and mark i e with fixing tape on cable while still on reel Leave the appropriate amount of heating cable at all power connection splice tee and end seal locations Refer to component installation instructions Add additional heating cable to trace the fittings and supports or for spiralling as required by the design specifications or consult Pentair product literature for design Protect all heating cable ends from moisture contamination and mechanical damage or other interference if left exposed before component installation Heating cable attachment recommendations The heating cable may be installed straight spiralled or in multiple runs as required by the design specification Pentair product literature or TraceCalc software Do not use metal attachments vinyl electrical tape or duct tape as heating cable damage may result Self Regulating technology allows for the multiple overlapping of the heating cable on to itself Power Limiting technology dictates that the heating cable can be overlapped only once on to itself If VPL cables are installed parallel to each other please allow for minimum 15 mm clearance For VPL heating cable only ES v o o Fix in p
6. 6 5 Pipe support shoe Figure 7 Side view Glass cloth tape Support shoe Pipe typical View from under Heating cable Pipe Refer to design specification for additional heating cable length ER Fix with self adhesive glass cloth tape p Thermally insulate and weatherproof to specification 4 COMPONENTS INSTALLATION General notes Select the required components from Pentair product literature or use the TraceCalc software Raychem component kits including power connections splices and end seals must be used to satisfy Standards and Approval Body requirements Installation instructions included in the kit must be followed including those for preparation of the heating cable conductors for connections Before assembly use the guide given in the instructions to ensure that the kit is correct for the heating cable and environment gt 4 1 Raychem self regulating and power limiting heating cables are parallel circuit design Do not twist the conductors together as this will result in a short circuit Components required For the installation of all components refer to the relevant component installation instructions Required for each heating cable run Power connection and insulation entry kit End seal As required Splice Tee splice Junction box Three connection kits and three insulation entry kits Accessories pipe straps fixing tape support brackets labels etc 4 2 Typical systems Fi
7. D 8 5 aed y uo paysew ase eru sjueuoduioo Mo jo suol e207 aen eu payeas pue ajaydwoo uonejnsu SjeululJ8 uoijeuuo aepo 1112 12 ejeg FBI hqe ndde esou au Bulpeay ssed q Bunejnsui saye 1581 sabbay aen amI 1qe2ndde 41 1esou au ssed q 6uipe y Buneynsul edid uo 3s sabbayy daquinu Buimeig Jequunu s ys lq 3In2J12 H04 500 3 NOILVTIVISNI MEH 133HS q40944 NOILVTIVLSNI aq aue saleyjideo qeu pue yas s e sow y uonipuoo poo ul uonejnsu aeq 3461 uo12 uu09 yeg 161 sjeuruJe uonoauuog 1uBn spue16 ayqeo pue ejqe B ne H qetu sulejs s uonoeuuoo u aen uoisou 02 jeniu 10 aunysiow Buryeaysaao sufis ON HLNOW 2804 SM 3H 39NVN3LINIVIN Tg LLLI 133HS 04023 39NVN41NIVN GNV NOI L93dSNI SIN3AINOO 8 SHHVIN3N ejeg uo paysew eu s u uodwo e ijoJd MO jo suone o1 ejeg S eululJe uoijoeuuo eueqd pesoj Aqu u q eAeu sjejsoui1eu pue saxoq 11 benoA 1112 12 ejeg elu Buipeey aiqeandde Jl eysowsay ssed q 1591 sabbay Troubleshooting guide A Symptom Overcu
8. TESTING 8 1 Recommendations Pentair recommends insulation resistance test before installing heating cable before installing thermal insulation prior to initial start up and as part of the periodic maintenance see Section 9 2 8 2 Test method After completing heating cable installation the insulation resistance between the conductors and the braid should be checked see Figure 11 using a 2 500 VDC megger Minimum readings should be 10 Megohms regardless of the heating cable length The installer should record the original values for each circuit on the installation record sheet see page 25 If a thermostat is installed it should be bypassed 21 Figure 11 Test between heating cable and braid 9 1 9 2 9 3 v OPERATION MAINTENANCE AND PIPE REPAIRS Heating cable operation Temperature exposure must not exceed that specified in Pentair product literature Exceeding those limitations will shorten the service life and may permanently damage the heating cable Pipe insulation must be complete and dry to maintain the correct temperature Inspection and maintenance Visual inspection Exposed heating cable and pipe insulation should be checked periodically to make sure that no physical damage has occured Meggering The system should be meggered regularly When meggering the insulation resistance from the main supply panel it is recommended that the test is performed between L N together
9. b Ex tD A21 IP66 see schedule in hazardous area approval Rated Voltage BASEEFA BTV1 QTVRT KTV1 XTV1 VPL1 110V 120V BTV2 QTVR2 KTV2 XTV2 VPL2 230V 277V VPL4 400V 480V PTB BTV2 QTVR2 KTV2 XTV2 230V 277V FAL Russia Kazakhstan Belarus For other countries contact your local Pentair representative BIV QTVR XTV KTV VPL Minimum Bending Radius at 20 C 15 mm 15mm 15 mm 25 mm 20 mm at 60 C 50 mm 50 mm 50 mm 50 mm 20mm Minimum Installation P o Temperature 60 C 60 C 60 C 60 C 60 C Maximum Maintain See Temperature 65 C 110 C 121 C 150 C table power on below Maximum Exposure Temperature 1000 hrs gso 110 C pech 2509C cumulative exposure power on Maximum Exposure Temperature 260 C continuous power off Self limiting Temperature in T3 P T6 T4 T2 20XTV2 T2 T accordance with 15 20XTV1 EN62086 1 5 1 11 Povver Limiting Temperature T By design The 250 C rating applies to all products printed MAX INTERMITTENT EXPOSURE 250C Maximum maintain power on temperature table Cable 110 V 230 V 254V 277V 400 V 480 V 5VPL1 CT 235 C OVPL1 CT 215 C 5VPL1 CT 190 C 20VPL1 CT 150 C 5VPL2 CT 230 C 225 C 225 C OVPL2 CT 210 C 200 C 195 C 5VPL2 CT 180 C 155 C 105 C 20VPL2 CT 150 C 5VPL4 CT
10. gure 8a Heating cable End seal Wallmounted IEK 25 04 Insulation entry kit JBU 100 Junction box for modular system C25 100 Connection kit Heating cable Splice as required Thermal insulation Glass cloth tape Insulation Entry kit SB 101 Thermostat Figure 8b JBM 100 Integrated power tee connection T 100 Tee or splice connection JBS 100 Integrated power connection shown with light 2i b a 150 Low profile power connection IEK 25 04 Insulation entry kit E 100 L Lighted end seal Low profile end seal Component installation hints We On horizontal pipes locate junction boxes below pipe wherever possible Pinch out drainhole in the stand when installing upside down gt Locate junction boxes for easy access but not exposed to mechanical abuse 4 Position junction boxes so that power cable and heating cable entries do not point upwards Figure 9a y F v 9 FF va JBS 100 L EP Integrated power connection with earth plate and light Fix lids in place where access not required Confirm junction box stopping plugs are correct for application and fixed firmly in place Route heating cable from junction box to insulation entry so as to avoid possible mechanical damage Do not strain heating cable as it exits enters junction boxes and insulation entries Ensure heating cable is fixed above pipe stra
11. heating cables they are included in the component installation instructions 3 6 1 Valve Figure 3 v Pipe Heating cable Glass tape The heating cable configuration will vary for different valve shapes and heating cable lenghts Refer to design specification for additional heating cable length Fix with self adhesive glass cloth tape Thermally insulate and weatherproof to specification including valve stem 3 6 2 Elbow Figure 4 Pipe Glass cloth tape typical Heating cable Thermal insulation 4 Fix heating cable to outside long radius of elbow ge Fix with self adhesive glass cloth tape gt Thermally insulate and weatherproof to specification 3 6 3 Flange Figure 5 Pipe Glass cloth tape typical Heating cable Additional heating cable is 2 3 times diameter of pipe typical B Fix with self adhesive glass cloth pipe 4 Thermally insulate and weatherproof to specification 3 6 4 Pipe bar hanger Figure 6 Bar hanger Sealer Weatherproofing Thermal insulation Glass cloth tape typical Heating cable D Do not clamp heating cable with support Heating cable must be over the support m No additional heating cable is required for bar or rod pipe hangers unless called for in the design specification then use loop length specified gt Fix with self adhesive glass cloth tape p Thermally insulate and weatherproof to specification 3
12. ion Work piece to be heated y gt Non Active Zone Heating Element Active Heating Length Heating Zone Zone Important For the Pentair warranty to apply the instructions that are included in this manual and product packages must be followed The installation must be compatible with local requirements applicable to electric heat tracing systems Conditions for Safe Use Refer to Hazardous area certification ATEX Certificate No Code Baseefa06ATEX0183X Za 2 GD Ex e IIC T6 Gb BTV PTB 09 ATEX 1115 9 i12 GD Ex tD A21 IP66 T80 C Baseefa06ATEX0185X Za 2 GD Ex e IIC T4 Gb QTVR PTB 09 ATEX 1116 9 l 2 GD Ex tD A21 IP66 T130 C Baseefa06ATEX0184X ka 2 GD Exe IIC T Gb XTV PTB 09 ATEX 1118 X 9 2 GD Ex tD A21 IP66 T 9C Baseefa06ATEX0186X 6 2 GD Ex e IIC 226 C T2 Gb PTB 09 ATEX 1117X 11 2 GD Ex tD A21 IP66 T226 C 9 11 260 Ex e II T Ex tD A21 IP66 VPL Baseefat6ATEX0188X T OC see schedule in hazardous area approval IECEx Certificate No Code ECEx BAS 06 0043X Ex e IIC T6 Gb ER ECEx PTB 09 0056X Ex tD A21 IP66 T80 C ECEx BAS 06 0045X Ex ellC T4 Gb QTVR ECEx PTB 09 0057X Ex tD A21 IP66 1302 ECEx BAS 06 0044 Ex e IIC T Gb A ECEx PTB 09 0059X Ex tD A21 IP66 T C ECEx BAS06 0046X Ex e IIC 226 C T2 Gb adi ECEx PTB 09 0058X Ex tD A21 IP66 T226 C VPL ECEx BAS 06 0048X Ex ell T G
13. ir com b PENTAIR NORGE Tel 47 66 81 79 90 Fax 47 66 80 83 92 salesno pentair com OSTERREICH Tel 0800 297410 Fax 0800 297409 info ptm at pentair com POLSKA Tel 48 22 331 29 50 Fax 48 22 331 29 51 salespl Qpentair com REPUBLIC OF KAZAKHSTAN Tel 7 495 926 18 85 Fax 7 495 926 18 86 saleskz pentair com POCCMR Ten 7 495 926 18 85 7 495 926 18 86 salesru pentair com SERBIA AND MONTENEGRO Tel 381 230 401 770 Fax 381 230 401 770 salesee pentair com SCHWEIZ SUISSE Tel 0800 551308 Fax 0800 551309 info ptm ch pentair com SUOMI Puh 0800 11 67 99 Telekopio 0800 11 86 74 salesfi pentair com SVERIGE Tel 46 31 335 58 00 Fax 46 31 335 58 99 salesse pentair com TURKIYE Tel 90 530 977 64 67 Fax 32 16 21 36 04 ptm sales tr pentair com UNITED KINGDOM Tel 0800 969013 Fax 0800 968624 salesthermaluk pentair com WWW PENTAIRTHERMAL COM All Pentair trademarks and logos are owned by Pentair or its global affiliates Pentair reserves the right to change specifications without prior notice 2013 2014 Pentair INDUSTRIAL HEAT TRACING SOLUTIONS EN RaychemSelfRegCable IM DOC71 R18 PCN 481825 000
14. ive glass cloth tape Recommended for use on stainless steel and cupra nickel surfaces or for installation temperatures lt 4 C Figure 2 ATE 180 Aluminium tape Use only if the design requires it ATE 180 improves the heat transfer and increases the power output of the heating cable Attach the heating cable to the pipe as shown in Figure 2 3 4 2 Spiral tracing a Alternative spiralling methods are shown in Figures 2a and 2b Only spiral heating cable on pipe when called for by design gt To prevent overheating be sure the location of the power limiting heating cable is planned so that the active heating zone will not extend into the component Read the kit installation instructions and plan the component location before permanently attaching the cable to the pipe Ensure that the active heating zones are located where heat is required i e on the pipe Spiral Pitch Table mm NB NPS Spiral Ratio mm inches Metres of cable per metre of pipe 1 1 1 2 1 3 1 4 1 5 25 1 250 170 140 110 100 32 11 4 310 210 170 140 130 40 11 2 350 240 190 160 140 50 2 430 300 240 200 180 65 21 2 520 360 290 240 210 80 3 630 430 350 290 260 90 31 2 720 490 390 330 290 100 4 800 560 440 370 330 125 5 990 680 550 460 400 150 6 1180 810 650 550 480 200 8 1520 1050 840 710 620 Example For pipe of 80 mm NB 3 NPS requiring 1 3 metres of heating cable per metre of pipe pitch is 350 mm Figure 2a
15. kits are fitted correctly and sealed Ensure that all places where valve stems support brackets thermostat capillaries etc exit the cladding are sealed 6 3 Marking E gt For power limiting heating cable install label LAB 1 35 as shown typical in figures 10a amp 10b Figure 10a Figure 10b gt Install Electric Traced signs along piping at suitable intervals 3 m intervals recommended on alternate sides as a warning 4 Mark on outside of insulation the location of heating cable components a For XTV and KTV heating cables if T class compliance was proven by stabilized design install LAB EX XTV KTV aluminium tag at approximately 75 mm from the entry of the junction box Figure 10c 20 7 POWER SUPPLY AND ELECTRICAL PROTECTION 7 1 Electrical loading Size overcurrent protective devices according to the design specification or applicable Pentair product literature If devices other than those specifically identified are used consult the Pentair representative for the appropriate sizing information 7 2 Residual current earth fault protection Pentair insists on the use of a 30 mA residual current device to provide maximum safety and protection However where there is a marked increase in nuisance tripping a maximum 300 mA residual current device may be used For heating cables installed in a hazardous area the use of residual current devices is normally a condition of their approval HEATING CABLE
16. lace with a minimum of two wraps the appropriate self adhesive glass cloth tape see figure 1 or plastic cable ties at 300 mm intervals and additionally where necessary Plastic cable ties must have a temperature rating that matches the system exposure temperature The heating cable s minimum bend radius must not be exceeded refer to p 2 Bend the cable only in upright position gt The heating cable does not bend easily in the flat plane Do not force such a bend as the heating cable may be damaged 3 4 1 Straight tracing ge Straight trace the pipe unless the design calls for spiralling see 3 4 2 On horizontal pipes fix on lower quadrant as shown in Figure 1 and not on bottom of pipe To prevent overheating be sure the location of the power limiting heating cable is planned so that the active heating zone will not extend into the component Read the kit installation instructions and plan the component location before permanently attaching the cable to the pipe Ensure that the active heating zones are located where heat is required i e on the pipe Thermally insulate and weatherproof to specification Figure 1 30p Top Pipe 45 Thermal nominal Glass cloth tape typical insulation Tight on pipe typical Pentair attachment tapes GT66 Self adhesive glass cloth tape General purpose tape Not for stainless steel surfaces or for installation temperatures lt 4 C GS54 Self adhes
17. of materials to the catalogue numbers of heating cables and electrical components received to confirm that proper materials are on site The heating cable type is printed on its outer jacket Temperature exposure must not exceed that specified in Pentair product literature Exceeding these limits will impair product performance Check that expected exposure is within these limits Ensure that the heating cable voltage rating is suitable for the service voltage available Do not energize cable when it is coiled or on the reel Inspect heating cable and components for in transit damage An insulation resistance test see section 8 on each reel is recommended Check piping to be traced m gt gt Ensure all pressure testing is complete and pipework has final paint coating Walk the system and plan the routing of the heating cable on the pipe Check pipework against specification drawing If different consult design authority Inspect piping for burrs rough surfaces sharp edges etc which could damage the heating cable Smooth off or cover with layers of glass cloth tape or aluminium foil 3 3 Heating cable handling Heating cable handling tips VV V 9 Paint and pipe coatings must be dry to the touch before heating cable installation When pulling the heating cable avoid sharp edges excessive pulling force kinking and crushing walking on it or running over it with equipment Heating cable pulling
18. or design conditions b modify to meet Pentair recommendations 3 Repair or reset to correct level of operation 4 Replace A f after 1 2 and 3 above the fault has not been located then either a Consult Pentair for futher assistance b Where local practices and conditions allow e g non hazardous areas isolate one section of heating cable from another by cutting in half and testing e g Insulation Resistance both halves until general area of damage is found Remove insulation and expose fault 31 BELGIE BELGIQUE Tel 32 16 21 35 02 Fax 32 16 21 36 04 salesbelux pentair com BULGARIA Tel fax 359 56 86 68 86 ax 359 56 86 68 86 salesee pentair com CESKA REPUBLIKA Tel 420 241 009 215 Fax 420 241 009 219 czechinfo pentair com DANMARK Tel 45 70 11 04 00 Fax 45 70 11 04 01 salesdk pentair com DEUTSCHLAND Tel 0800 1818205 Fax 0800 1818204 salesde pentair com ESPANA Tel 34 902 125 307 Fax 34 91 640 29 90 ptm sales es pentair com FRANCE T l 0800 906045 Fax 0800 906003 salesfr pentair com HRVATSKA Tel 385 1 605 01 88 Fax 385 1 605 01 88 salesee pentair com ITALIA Tel 39 02 577 61 51 Fax 39 02 577 61 55 28 salesit pentair com LIETUVA LATVIJA EESTI Tel 370 5 2136633 Fax 370 5 2330084 info baltic pentair com MAGYARORSZAG Tel 36 1 253 7617 Fax 36 1 253 7618 saleshu pentair com NEDERLAND Tel 0800 0224978 Fax 0800 0224993 salesnl Qpenta
19. ps such as used for junction box support brackets Fix all low profile components e g heatshrink end seals in place with self adhesive glass cloth tape THERMOSTATS In temperature sensitive applications thermostatic control may be necessary If maximum temperature is a concern consult your Pentair representative for design assistance Follow the installation instructions supplied with the thermostat Use the proper wiring diagram for the heating cable layout and control method desired y y 9 9 F v THERMAL INSULATION AND MARKING Pre insulation checks Visually inspect the heating cable and components for correct installation and damage See Section 10 if damaged Insulation resistance Megger testing as per Section 8 is recommended prior to covering the pipe with thermal insulation Insulation installation hints Correct temperature maintenance requires properly installed and dry thermal insulation Thermally insulate and weatherproof to design specification Check insulation type and thickness against the design specification To minimize potential heating cable damage insulate as soon as possible after tracing Check that all pipework including fittings wall penetrations and other areas have been completely insulated Ensure that heating cable is not damaged during installation of cladding for example by drills self tapping screws and sharp edges of cladding Check that all insulation entry
20. rrent protection trips or blows Probable Causes Electrical fault at a damaged heating cable b faulty splices or tees c end seal d connection Circuit oversized Start up below design temperature Defective electrical protection Symptom RCD trips Probable Causes Earth fault at a damaged heating cable b faulty splices or tees c end seal d connection Excessive moisture in a junction boxes b splices and tees end seals High leakage currents due to a combination of excessive lengths of power cable and heating cable Mains borne disturbances Defective RCD 28 Corrective Actions 1 Investigate and remedy see note 1 2 Resize or redesign within Technical Databook Guidelines If larger protection is required ensure supply cables are compatible 3 a redesign for lower start up temperatures b preheat pipe from alternative heat source to within exposure temperatures given in Product Data Sheets Energize part of circuit followed by remainder e g in sequence 4 Replace Corrective Actions 1 Investigate and remedy see note 1 2 Dry out and reseal or remake immediately Perform insulation resistance test 10 MQ minimum 3 Redesign 4 Redesign distribution guidance is available from Pentair 5 Replace 29 Symptom No power output Probable Causes Loss of supply voltage due to a overcurrent or residual curren
21. t protection operating b loose terminals in junction box loss of supply cable continuity e 9 open circuited from damage 2 Control thermostat is connected in the normally open position 3 High resistance connection at a junction box terminals b splices and tees D Symptom Low pipe temperature Probable Causes 1 Wet thermal insulation 2 Design error 3 Incorrect setting or operation of controls e g thermostats 4 Heating cable has been exposed to excessive temperature beyond rating Note Locate faults by the following steps 1 2 30 Visually inspect the power connections splices and end seals for correct installation Look for signs of damage at a Valves pumps flanges and supports bl Areas where repairs or maintenance work has been carried out Look for crushed or damaged insulation and cladding along the pipe Corrective Actions 1 Restore supply voltage a following A and B page 31 b re tighten terminals NB If excessive heating has occured due to high resistance replace terminals or crimps c locate damage and repair 2 Reconnect to normally closed position 3 Locate and remedy by a re tighten b repair NB If excessive heating has occured due to high resistance replace terminals or crimps Corrective Actions 1 Remove and replace with dry insulation of correct specification and ensure complete weatherproofing 2 a check with competent authority f
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