HD-1/HD-2 Series User`s Manual
Contents
1. 10 3 6 FRICTION idet rp Eee ite o e ee o i y poti eaten neben e uad 10 VIBRATION er t rro E d E pep eH He GOOD QU ec o RE DR 11 OGIGINGE Ede 11 3 9 EDDY Ud v ic M 12 3S IOTEMPERATURBRRISE t ir eth in te ye tectae tet baeo een teni veinte 12 4 OPERATING PRINCIPLES 25 ia ca iuo sna e Una ERN ER UE s FUR XUI E CN LEA RUE EUR C Sr MOKCE I REIN SEE 13 2 1 SPEED iss uUOS EIOS NE IE ene ais 13 E PABLO 60 13 221 TORQUE STABILITY 1 1 3 20 tet t testi te terae tette o tend tenir eee nese 13 5 CALIBRATION E 14 2 1 PREPARATION RN ERR UU e DEO ae HE 14 2 2 CALIBRATION PROCEDURE 2 2 eerte re t vati pent ease ep eta cp a d 14 Magtrol Dial Weight Dynamometers User s Manual TABLE OF FIGURES 2 INSTALLATION CONFIGURATION Figure 2 Torque 3 2 3 TESTING CONSIDERATIONS 3 1 Dynamometer Side View icc te EES Figure 3 2 HD 106 1 Power Absorption Curve Figure 3 3 HD 400 1 2 Power Absorption Curve2. Full Scale Torque Maximum Power Ratings Model Range One RangeTwo RangeThree Speed 5 Minutes Continuous oz in accuracy oz in accuracy oz in accuracy rpm W W HD 106 1 0 5 3 5 96 1 2 2 1 30 000 35 7 HD 400 1 2 2 8 2 16 1 20 000 200 55 HD 400 2 8 2 16 1 32 1 20 000 200 55 HD 500 1 25 2 50 19 100 1 15 000 400 80 HD 600 1 50 196 100 19 200 1 10 000 600 100 HD 700 1 100 196 200 196 400 1 10 000 700 150 705 1 200 196 400 19 800 1 8 000 1400 300 Hysteresis BRAKE Power Hysteresis brakes require direct current for torque control They will not respond to alternating current above a few Hz The nominal voltage rating for all Magtrol Hysteresis Brakes is 28 VDC The following is a listing of the resistance and current for each brake by dynamometer model Resistance F S Current Model Q A HD 106 1 171 0 164 HD 400 1 2 80 0 350 HD 500 1 120 0 233 HD 700 1 80 0 350 HD 705 1 40 0 700 2 Installation Configuration 2 1 2 2 2 3 2 3 1 2 3 2 COUNTER WEIGHTS Begin by installing the dynamometer counter weights that were shipped with your dynamometer There should be as many counter weights 2 or 3 as there are torque scales the dynamometer dial This total includes the minimum scale weight permanently attached to the brake assembly Note The dynamometer brake assembly should swing freely DYNAMOM
3. eee atas 7 Figure 3 4 HD 500 1 Power Absorption Curve Figure 3 5 HD 600 1 Power Absorption Curve Figure 3 6 HD 700 1 Power Absorption Curve Figure 3 7 HD 705 1 Power Absorption Curve Figure 3 8 Examples of Possible Shaft 10 3 9 Hysteresis Brake CVosS Sectlon ueste detener n 11 4 OPERATING PRINCIPLES Figure 4 1 Optical Encoder Circuit iaceret nitri UE 13 5 CALIBRATION Figure 5 1 Calibration Setup occi erede pee elicit EH ere eee te edes 14 1 Introduction 1 1 12 1 2 1 UNPACKING YOUR DIAL WEIGHT DYNAMOMETER Your Hysteresis Dynamometer was packaged in reusable shock resistant packing material that will protect the instrument during normal handling 1 Make sure the carton contains all dynamometer hardware counter weights applicable power supplies User Manual CD Rom and any other small items Note brake The counter weights may be wrapped separately or installed on the immediately notify the carrier and Magtrol s Customer Service Department Inspect the contents for any evidence of damage in shipping In the event of shipping damage Note returning the instrument for calibration or servicing Save all shipping cartons and packaging material for reuse when TECHNICAL SPECIFICATIONS
4. I MINUTES TO 100 C Figure 3 3 HD 400 1 2 Power Absorption Curve HD 500 1 0 3745 0 3750 Snan Diameter 9 512 mm 9 525 mm Shaft Height 4 00 in 101 6 mm 25 oz in Torque Ranges 50 oz in 100 oz in Input Inertia 8 05 x 10 Ib ft s Maximum Speed 20 000 rpm Maximum Input Power 375W g D a I MINUTES TO 100 C Figure 3 4 HD 500 1 Power Absorption Curve User s Manual Magtrol Dial Weight Dynamometers HD 600 1 0 4995 in 0 5000 in Shaft Diameter 12 687 mm 12 700 mm Shaft Height 4 812 in 122 22 mm 50 oz in Torque Ranges 100 oz in 200 oz in Input Inertia 2 34 x 10 Ib ft s2 Maximum Speed 20 000 rpm Maximum Input Power 550 W 1 0 80 60 a 40 I 20 0 0 10 20 30 40 50 60 70 80 MINUTES 1008 Figure 3 5 HD 600 1 Power Absorption Curve HD 700 1 0 4995 in 0 5000 in Shaft Diameter 12 687 mm 12 700 mm Shaft Height 5 875 in 149 2 mm 100 oz in Torque Ranges 200 oz in 400 oz in Input Inertia 5 51 x 107 Ib ft s Maximum Speed 15 000 rpm Maximum Input Power 650W D a 5 I MINUTES TO 100 C Figure 3 6 HD 700 1 Power Absorption Curve Magtrol Dial Weight Dynamometers User s Manual HD 705 1 0 4995 in 0 5000 in Shaft Diameter 12 687 mm 12 700 mm Shaft Height 5 875 in 149 2 mm
5. 200 oz in Torque Ranges 400 oz in 800 oz in Input Inertia 1 101 x 10 Ib ft s Maximum Speed 10 000 rpm Maximum Input Power 1400W g Ol D a 6 I MINUTES TO 100 C Figure 3 7 HD 705 1 Power Absorption Curve 3 4 FIXTURES AND COUPLINGS When mounting the test motor please consider the following Construct precise fixtures that provide proper shaft alignment Secure the test motor in the fixture to prevent torsional movement and bolt the fixture to the dynamometer base plate Give consideration to the interaction of materials between the motor and test fixture For example a magnetic steel plate placed against the exposed lamination of an open frame motor can significantly influence performance Some thin shell PM permanent magnet motors may be similarly affected The dynamometer base plate material is an aluminum tool plate that is easily drilled and tapped The use of helix thread inserts is a good idea if you are going to interchange fixtures often Note For an additional charge Magtrol can perform base plate modifications User s Manual Magtrol Dial Weight Dynamometers 3 5 3 6 The following diagram illustrates examples of possible shaft misalignment PARALLEL OFFSET Figure 3 8 Examples of Possible Shaft Misalignment The use of high quality double flexure couplings is recommended to help correct any misalignment problems This type of coupling two flexing elements separ
6. 2 INSTALLATION CONFIGUPIATION 2 2 1 COUNTER WEIGHTS tris etie ee O ENRERE Ue t oue 2 22 DYNAMOMETER EENVELJINCY a rettet rr pe RR cage dct e resta 2 2 3 SX STEM CONBIGURATION G E ER n IRURE deter tese 2 231 SPBED READOUTS dote Re dete aes rere tetas etn uu oe 2 2 3 2 POWER SUPPLIES p rr Ri eR IR Io HERD GRO eed eae IER OO RUE Eae 2 2 33 CONNECTIONS tip OBERE agii eH ERI e iei 3 2 4 INITIAL 3 TESTING CONSIDERATIONS ii cniin inikn uni SIN ORENSE IAE 4 SAFETY RU E cbs cha senses iecit 4 32 ACCURAGY CUR HIER uie Et ete t aita stupet ONDE 4 324 TORQUE SCALE GRADUATIONS 5 3 3 POWBR DISSIPATION 2 cette ie ueteri HIER Ote iri pere tet eade ee RT ERE ORTU ERE EIU RE 3 3 3 1 POWER ABSORPTION CURY ES 2 rra ep hb e Er cH Ip E PU E 5 FIXTURES AND COUPLINGS etc em recepte eu Ee to cede ut eee een 9 3 5 WINDAGE C
7. DESTRUCTION OF THE COUPLING STOP WARNING SHAFT COUPLINGS OPERATING AT SPEEDS 3 8 COGGING Rotor Poles Figure 3 9 Hysteresis Brake Cross Section This cross section shows by one tooth the magnetic relationship of the hysteresis brake elements If the dynamometer shaft is at rest with torque applied and if the torque control is then reduced to zero a magnetic salient pole will be temporarily imposed on the rotor of the brake If the shaft is then rotated slowly the magnetic poles on the rotor will attempt to align with the adjacent case pole tooth form This is often referred to as cogging The action is sinusoidal first it tries to resist rotation and then as the rotor passes through the tooth form it subsequently supports rotation At a few hundred rpm these forces integrate resulting in an effective torque of nearly zero To avoid magnetic cogging before the shaft comes to rest reduce the torque control to zero To remove cogging once established reapply current on the dynamometer Then decrease the current to zero while simultaneously rotating the dynamometer shaft User s Manual Magtrol Dial Weight Dynamometers 3 9 3 10 EDDY CURRENTS There is some Eddy current generation within the brake rotor These magnetically induced currents cause an increase in brake torque proportional to speed The larger the hysteresis brake the higher the rotor surface velocity Additionally as brakes becom
8. ETER LEVELING Level the dynamometer base plate in all planes The bubble level device on the base plate is convenient for front to back leveling For side to side adjustment it is more accurate to level the dynamometer by observing the torque dial for a ZERO reading It works best to use the most sensitive torque scale by removing one or both of the counter weights Figure 2 1 Torque Scale SE Note There should be nothing connected to the dynamometer shaft SYSTEM CONFIGURATION SPEED READOUTS If an optional speed reading instrument or Model 3410 Torque Display is ordered with the dynamometer a 14 pin cable for the Torque Display is included Power SupPLiES Power supply options for brake control include the Model 5200 2 and the Model 5210 2 The 5200 is unregulated and operates in an loop current control mode while the 5210 is a current regulated closed loop controller A 2 pin connection cable is provided with the power supply Magtrol Dial Weight Dynamometers User s Manual 2 3 3 2 4 CONNECTIONS Connect all items together The dynamometer controller and speed readout if applicable interconnections are straight forward using the cord sets INITIAL CHECKOUT 1 Besure the TORQUE control on the power supply is off CCW 2 Turn the speed readout device if applicable and the torque controller 3 Rotate the dynamometer shaft manually while simultaneously adjusting the TORQUE CONTROL cl
9. MAGTROL HD 1 HD 2 Series Dial Weight User s Manual Purchase Record Please record all model numbers and serial numbers of your Magtrol equipment along with the general purchase information The model number and serial number can be found on either a silver identification plate or white label affixed to each unit Refer to these numbers whenever you communicate with a Magtrol representative about this equipment Model Number Serial Number Purchase Date Purchased From While every precaution has been exercised in the compilation of this document to ensure the accuracy of its contents Magtrol Inc assumes no responsibility for errors or omissions Additionally no liability is assumed for any damages that may result from the use of the information contained within this publication COPYRIGHT Copyright 1999 2008 Magtrol Inc rights reserved Copying or reproduction of all or any part of the contents of this manual without the express permission of Magtrol is strictly prohibited Ist Edition rev B December 2008 J MAGTROL Revisions This Manual The contents of this manual are subject to change without prior notice Should revisions be necessary updates to all Magtrol User s Manuals can be found at Magtrol s web site at www magtrol com support manuals htm Please compare the date of this manual with the revision date on the web site then r
10. RATING PERSONNEL WITH DANGEROUS AND COSTLY CONSEQUENCES e Always connect the motor frame to a high current capacity water pipe earth ground e Be sure the motor control circuit breakers cannot be bypassed by accident Variable auto transformers are especially hazardous When operating dynamometers with blowers hearing protection must be worn ACCURACY Following is a list of several factors that affect the apparent accuracy of the torque readout e Coupling Losses If the coupling becomes hot to the touch or if the dynamometer or motor vibrate after a period of running coupling loss error could occur up to several percent depending on the size of the motor and dynamometer For more detail refer to Section 3 4 Fixtures and Couplings e Windage Negligible at speeds up to 6000 rpm This effect is described more extensively in Section 3 5 Windage Note Much of the above is dependent upon motor horsepower fixturing and other circumstances beyond the control of Magtrol If reasonable care is exercised and calibration and maintenance are performed on a regular basis motor test data accuracy better than 1 596 of torque speed value can generally be expected Magtrol Dial Weight Dynamometers User s Manual 3 2 1 3 3 3 3 1 SCALE GRADUATIONS Some torque scale graduations are more difficult to read rapidly than others What usually works well for most people is to record torque data poi
11. ated by a solid link inherently tolerates greater parallel offset If you would like more specific coupling recommendations contact Magtrol Technical Assistance For precise misalignment tolerances consult your coupling manufacturer WINDAGE Although a smooth surface the dynamometer rotor will drag air around with it This air friction is tangential to the surface and impinges upon the stationary field assembly The viscous drag that results then becomes part of the motor load and torque reading However there is a small amount of air dissipated as pumping loss Since this appears as a load on the motor not measured by the dynamometer it becomes a source of error Windage effects on accuracy tests have been conducted on all Magtrol dynamometers The percentage of torque loss due to windage ranges between 0 025 and 0 20 of full scale at maximum rated rpm The larger percentage applies toward the smallest capacity dynamometer HD 106 Because windage is proportional to the square of speed it magnifies rapidly above rated speed Conversely at one half of the rated speed the effect becomes immeasurably small FRICTION Friction of the shaft bearings is a measurable load but some friction can exist in the carrier bearing When correctly loaded and lubricated the friction is insignificant The value may be quantitatively established by the following procedure 1 Remove all attachments to the dynamometer shaft 2 Swing the brake assemb
12. e larger the rotor cross sectional area increases Each of these factors increase Eddy current generation The combination results in speed related torque increase exhibiting a more pronounced effect on larger dynamometers On the smaller dynamometer sizes 290 to 426 1000 rpm is typical TEMPERATURE RISE Temperature rise has a more complex effect on hysteresis brake load torque and is difficult to quantify As the temperature of the brake increases differential expansions cause dimensional changes that tend to increase torque Conversely electrical resistance in the rotor increases with temperature resulting in decreased Eddy current generation and torque all in a variable frame Where current and speed remain fixed there may be a gradual torque increase over a period of a few moments This will generally stabilize at 0 5 for small dynamometers up to HD 500 1 to 1 596 of the starting torque value per 1000 rpm of applied speed 4 Operating Principles 4 1 4 2 4 2 1 SPEED The dynamometer is shipped with an internal speed pickup and two cords one terminating with a 2 pin plug for the brake power the other is a 14 pin plug servicing an optical encoder This encoder consists of an infrared transmitter receiver pair On the end of the dynamometer shaft positioned between the LED and detector is an optical disc with opaque and clear segments Rotation of the disc results in the detector generating a frequency of 60 p
13. efer to the manual s Table of Revisions for any changes updates that have been made since this edition REVISION DATE 1st Edition Revision B August 2008 TABLE OF REVISIONS Date Edition Change Section s 12 18 08 1st Edition Rev All dynamometers now shipped with a speed pickup 4 1 2 pin and 14 pin cable 12 18 08 1st Edition Rev The Model 5400 Tachometer was replaced with the Model 2 3 1 3410 Torque Display as the primary speed readout option 08 01 06 1st Edition Rev Redesigned manual to be consistent with Magtrol format all 12 1999 1st Edition First PDF version Table Contents REVISIONS TO THIS MANUAL nid cao am dx KR a RR EXT E EE n FEX SE RR NR EHI EUR Tu SERIE LR QI FANE IIR E REVISION 1 REVISIONS nopi TABLE ll TABLE OF FIGURES IDE abi aede 1 m 1 11 UNPACKING YOUR DIAL WEIGHT DYNAMOMETER riot tr t teh eer t t eee gerer 1 1 2 TECHNICAL SPECIFICAT IONS E rho 1 124 HYSTERESIS BRAKE CONTROL reete tee 1
14. h horsepower hp for use in the heat rise curves hp ozin rpm x 1 00 10 hp lbft rpm x 1 90 10 hp ozft rpm x 1 19x10 hp lbin x rpm x 1 59 103 hp gcm rpm x 138 103 hp Nm x rpm x 140x10 Note Please take a moment to familiarize yourself with any limitations that may apply to your specific dynamometer and motor testing requirements User s Manual Magtrol Dial Weight Dynamometers The following sketch shows the identifications for shaft height H and diameter D used in the following specifications Figure 3 1 Dynamometer Side View HD 106 1 0 1245 in 0 1250 ahan Diameter 8 163 mm 3 175 mm Shaft Height 3 50 in 88 9 mm 0 5 oz in Torque Ranges 1 0 oz in 2 0 oz in Input Inertia 7 04 x 107 Ib ft s Maximum Speed 30 000 rpm Maximum Input Power 40W 05 04 03 02 HORSEPOWER 0 4 8 2 16 20 24 28 32 MINUTES TO 100 C Figure 3 2 HD 106 1 Power Absorption Curve Magtrol Dial Weight Dynamometers User s Manual HD 400 1 2 0 2495 in 0 2500 in Shaft Diameter 6 338 mm 6 350 mm Shaft Height 3 50 in 88 9 mm 2 oz in Torque Ranges 1 8 oz in 16 oz in 8 oz in Torque Ranges 2 16 oz in 32 oz in Input Inertia 1 55 x 10 Ib ft s Maximum Speed 25 000 rpm Maximum Input Power 190W D a
15. ly up to full scale by hand 3 Carefully allow the assembly to return to zero without swinging back and forth 4 Repeat steps 2 and 3 this time in the opposite direction and note the reading The difference between zero and the second reading should be within the accuracy specifications listed in Section 1 2 Technical Specifications During actual motor testing there is usually enough system vibration to settle negating frictional effects If excessive drag is present mechanical realignment may be required dependent upon dynamometer size Certain mechanical factors need to be determined before corrective action proceeds Please contact Magtrol Technical Assistance Magtrol Dial Weight Dynamometers User s Manual 3 7 VIBRATION rotating dynamometer assemblies are precision balanced however the dynamometer shaft is cantilevered This may cause vulnerability to radial forces At high speeds some vibration and noise are inevitable but not necessarily harmful However excessive resonant vibrations caused by bent shafts poor alignment and out of balance couplings will produce excessive data errors and are a safety hazard ABOVE THEIR DESIGN LIMITS ARE EXTREMELY HAZARDOUS MANY COUPLINGS CONTAIN SOMEWHAT LOOSELY SUPPORTED FLEXURE ELEMENTS WHEN OVERDRIVEN EXCESSIVE CENTRIFUGAL FORCE MAY DISPLACE THEM OUT OF AXIAL ALIGNMENT AS THIS HAPPENS THEY IMMEDIATELY BEGIN TO ABSORB ENERGY RESULTING IN SEVERE VIBRATION AND
16. nts from the easiest reading scale then correct all data to correspond to the particular range counterweight selected by multiplying or dividing by 2 or 4 POWER DISSIPATION All Magtrol Dynamometers are power absorption instruments As a dynamometer loads a test motor it is absorbs horsepower from the motor into the hysteresis brake The brake then converts this mechanical energy into heat There are finite limits to the amount of energy and resulting temperature rise that any absorption brake can withstand Rapidly rising operating temperatures from excessive power input can cause severe mechanical distortion of the rotor assembly This in turn may cause the rotating assembly to contact the stationary members that surround it Once this happens metal transfer and ultimately seizing of the brake assembly may occur Excessive power over extended periods of time may result in more obscure damage including breakdown of bearing lubricants and degradation of magnetic coil insulation Power ABSORPTION CuRVES The following graphs Figures 3 1 through 3 6 represent the maximum power heat that the dynamometer can dissipate over time The specifications shown are conditional upon the following e Maximum brake temperature 100 C 212 F e Ambient temperature 25 5 7729 F The following torque speed to horsepower conversion formulas are provided for your convenience They are sufficiently accurate within 1 to establis
17. ockwise very slowly 4 Stop when you begin to feel resistance occurring on the shaft 5 Ifthere is a speed reading instrument note the speed rpm reading 6 Return the TORQUE CONTROL to zero Note With the TORQUE CONTROL off you may notice slight torque pulsations on the shaft This is normal For a further description of salient poles please refer to Section 3 8 Cogging 3 Testing Considerations 3 1 3 2 A number of factors must be taken into consideration before running a test including safety accuracy power dissipation fixturing couplings windage friction vibration cogging Eddy currents and temperature rise The following sections describe these factors and their effects in further detail SAFETY For general safety considerations please follow these few common sense rules e sure that your coupling is adequately rated for the speed and torque that you intend to run sure all rotating elements are covered e Always wear safety glasses when working around dynamometer test equipment e Do not wear loose clothing or ties when working around dynamometer test equipment e Never allow anyone to stand close to the side of or lean over a rotating shaft coupling e Insulate electrical internal and external motor connections CAUTION POWER LINE FAULT INTO THE DYNAMOMETER FRAME COULD PASS TRANSIENT SURGE THROUGH ALL INTERCONNECTED INSTRUMENTS ANY COMPUTER IN USE OR OPE
18. on lift the weight dial assembly until a balance is attained between the assembly and the beam Observe the deviation if any Remove the calibration beam The dynamometer is calibrated and ready for motor testing Testing Measurement and Control Torque Speed Power Load Force Weight 2 MAGTROL 70 Gardenville Parkway Buffalo New York 14224 USA Phone 1 716 668 5555 Fax 1 716 668 8705 E mail magtrol 9 magtrol com Tension Displacement MAGTROL SA Route de Montena 77 1728 Rossens Fribourg Switzerland Phone 41 0 26 407 3000 Fax 41 0 26 407 3001 E mail magtrol 9 magtrol ch www mMagtirol com Subsidiaries in Great Britain Germany France China India Worldwide Network BUREAU VERITAS of Sales Agents Certification
19. otor and not errors 13 5 Calibration 5 1 5 2 CALIBRATION PREPARATION To check the torque calibration accuracy it is necessary to apply a precisely known torque value The most accurate method to apply a known torque is with the use of a beam and weight system Various sizes of torque calibration beams and precision calibration weights are available from Magtrol The pin location on the torque beam precisely fixes the distance Therefore the force weight required will be equal to the torque value divided by the distance on the beam CALIBRATION PROCEDURE 1 2 Apply full torque to the dynamometer until shaft is restrained from rotating Install the calibration beam on the dynamometer shaft as shown in the following diagram Lock the beam with the locking screw against the flat on the shaft Do not hang the weight until instructed to do so in step 4 With the Base Plate and the Beam level Dial Reading DxW Figure 5 1 Calibration Setup Note The calibration beam must be maintained exactly level at all times Using lightweight but strong line form a loop and attach it to the weight Note Do not use a wire hook Hooks will generally apply the force slightly off the center line of the pin Suspend a known weight at a known distance from the beam See Section 5 1 Calibration Preparation While preventing the beam from rotating and maintaining it in a level positi
20. ulses per shaft revolution 5 Pin 7 R2 R1 200 gt 470 5 2 OPB963 T 4 Fo Pin 10 1 3 U1 Pin 8 Figure 4 1 Optical Encoder Circuit TORQUE Torsional force acting upon the hysteresis brake is produced by the test motor and applied to the brake s rotor shaft assembly Whatever torque exists on the rotor shaft must be reacted upon equally by the suspended brake dial weight assembly Since the brake assembly is imbalanced by the suspended weight attached to it torsional force will lift the weight The graduated dial provides a readout value equal to this torque Once the weights are calibrated to match the dial graduations the system accuracy becomes permanently fixed When torque is defined by a point on the radius of a weight lifted in a circular motion the scale derivation is inherently a cosine function thus the nonlinear scale graduations TORQUE STABILITY A major advantage in using a hysteresis brake as a loading means is the ability to produce torque essentially independent of speed This permits very low speed and locked rotor torque testing Three factors have a minor secondary influence on hysteresis brake torque They are e Hysteresis brake control current see Section 1 2 1 e Eddy current see Section 3 9 e Temperature rise see Section 3 10 Note Torque changes as a result of these influences are always part of the actual torque measured as applied to a test m
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