Woodward MPU, Manual

Page 1: ...Manual 82510 Revision V 8 2022 Original Instructions Magnetic Pickups and Proximity Switches for Electronic Controls Reference Manual Released ...

Page 2: ...o the equipment Any such unauthorized modifications i constitute misuse and or negligence within the meaning of the product warranty thereby excluding warranty coverage for any resulting damage and ii invalidate product certifications or listings Translated Publications If the cover of this publication states Translation of the Original Instructions please note The original source of this publicat...

Page 3: ...y Switch Wiring 14 APPENDIX USING THE OUTPUT OF A WOODWARD MPU TO DRIVE A REMOTE TACHOMETER OR OTHER DEVICE 15 REVISION HISTORY 16 Illustrations and Tables Figure 1 1 Magnetic Pickup Dimensions 4 Figure 1 2 Magnetic Pickup Output Waveforms 5 Figure 1 3a MPU Models 6 Figure 1 3b CSA ATEX Models 7 Figure 1 4 Maximum Air Gap Allowed to Provide Usable Signals for Most Electronic Controls 8 Figure 1 5 ...

Page 4: ...nal injury loss of life or property damage The overspeed shutdown device must be totally independent of the prime mover control system An overtemperature or overpressure shutdown device may also be needed for safety as appropriate Personal Protective Equipment The products described in this publication may present risks that could lead to personal injury loss of life or property damage Always wear...

Page 5: ...es a dynamic discontinuity of magnetic material in the field of the pickup will produce an electrical voltage Although gears are the normal devices measured by an MPU other devices such as a vibrating surface moving bar crank wheel spokes or a steel screw head mounted on some moving surface will work equally well if surface speed and other factors are taken into account The MPU may be excited by a...

Page 6: ... the optimum dimensions of A B C and F are given as they relate to D the diameter of the pole piece of the magnetic pickup The optimum relationship for maximum output is as follows A equal to or greater than D B equal to or greater than C C equal to or greater than three times D F equal to or greater than D Released ...

Page 7: ...ic material The gap between the pickup and the outside diameter of the gear should be set normally between 0 25 mm and 1 02 mm 0 010 inch and 0 040 inch at the closest point Ensure the gear has less than 0 51 mm 0 020 inch diametric runout Since the signal strength is inversely proportional to gap distance a weak signal may be generated with more than 1 02 mm 0 040 inch gap A shield of non magneti...

Page 8: ...inches per second IPS is related to revolutions per minute rpm by the following Surface Speed rpm x π x gear diameter 60 The diametral pitch for the gear is obtained by the formula Diametral Pitch number of teeth 2 gear diameter inches The gear module is obtained by the formula Gear Module gear diameter mm number of teeth 2 Released ...

Page 9: ... with a finer diametral pitch than 8 gear module 3 2 may be used with a corresponding decrease in output voltage A diametral pitch of 20 gear module 1 27 is the finest that may be used with this pickup without two teeth appearing over the pole piece at the same time When adjusting the clearance between the pickup pole piece and the gear adjust the pickup so the output voltage is a minimum of 1 5 V...

Page 10: ... thread one 360 turn counterclockwise will move the pickup out 0 0555 inch 1 41 mm The metric pickup will move 1 5 mm per turn If the pickup has a 3 4 20 mounting thread the pickup will move out 0 050 inch 1 27 mm per turn Screw out the amount required for the desired gap If possible run the gear slowly through 360 rotation to check the clearance of the pickup When the gap is set tighten the jam n...

Page 11: ...ard models of pickups including the metric model require mating connector number MS 3106A 10SL 4S These connectors are not furnished with the pickups but may be ordered if desired The hazardous duty and explosion proof models have leads attached to the pickups and the heads have 1 2 inch female pipe threads for installing conduit or pipe Released ...

Page 12: ...eed sensor The setting compound in the conduit seal shall be suitable for at least 120 C Only wires rated for at least 100 C shall be used for connections The mechanical and electrical installation shall only be carried out by trained personnel with knowledge of the requirements for installation of explosion proof equipment in hazardous areas The entire installation procedure shall be carried out ...

Page 13: ...e Check pickup leads with a high impedance ac voltmeter for 10 to 20 V ac rms Reconnect the pickup and check the speed sensor input terminals for a minimum 1 5 V ac rms at the lowest controlling speed Check the pickup and gear clearance if voltage is low MPU Resistance List Long Standard Model 250 Ω max Extra Long Standard Model 250 Ω max Short Standard Model 220 Ω max Standard Metric Model 250 Ω ...

Page 14: ...goes high nearly equal to the supply voltage After the tooth has passed the output switches back to zero volts until another tooth comes into position Typical wiring for a sinking type proximity switch is shown in Figure 2 2 When wired as a source type proximity switch the output is normally high nearly equal to the supply voltage When a gear tooth is within the sensing range of this proximity swi...

Page 15: ...ance of metal around the front of the sensor and mounting bracket Some Woodward controls have less than 300 Ω of dc impedance In these cases the probe may be damaged by excess current when the engine is stopped To prevent this possible damage a 300 Ω 2 W resistor should be installed in series with the probe Proximity Switch Power Supply Proximity switches provided by Woodward require an external p...

Page 16: ...equate load resistance Proximity Switch Wiring The proximity switches supplied by Woodward are wired for a sinking type output Figure 2 2 shows a typical wiring method Other proximity switches not supplied by Woodward are wired dc source Figure 2 3 shows a typical dc source wiring method AC proximity switches are seldom used with Woodward controls Figure 2 2 Suggested Wiring for a Sinking Type Pro...

Page 17: ...f the remote device and the governor is not reversed 2301 Governor The 2301 governor is isolated from ground care should be taken that any device added to the system is also isolated from earth ground Shielding Governor circuits have been carefully shielded and circuits to remote devices must also be shielded from interference since this could prevent adequate governor control Inadequate shielding...

Page 18: ...Changes in Revision V Removed SIL3 drawings Added notes for SIL versions of CSA ATEX models pages 10 11 Revised ambient temperature page 10 Changes in Revision U Added SIL3 drawing Figure 1 3c Changes in Revision T Added Installation and Operation Safety Requirements summary Released ...

Page 19: ...Manual 82510 Magnetic Pickups and Proximity Switches Woodward 17 This Page Left Intentionally Blank Released ...

Page 20: ...522 1519 USA 1041 Woodward Way Fort Collins CO 80524 USA Phone 1 970 482 5811 Email and Website www woodward com Woodward has company owned plants subsidiaries and branches as well as authorized distributors and other authorized service and sales facilities throughout the world Complete address phone fax email information for all locations is available on our website Released ...