Table of Contents
Advertisement
Quick Links
- 1 General Information
- 2 Chapter 1. Magnetic Speed Pickups
- 3 Figure 1-1. Magnetic Pickup Dimensions
- 4 Figure 1-3A. Mpu Models
- 5 Figure 1-3B. Csa/Atex Models
- 6 Figure 1-4. Maximum Air Gap Allowed to Provide Usable Signals for most Electronic Controls
- 7 Installation and Operation Safety Requirements
- 8 General Information
- Download this manual
Advertisement
Table of Contents
Related Manuals for Woodward MPU
Summary of Contents for Woodward MPU
- Page 1 Released Manual 82510 (Revision V, 8/2022) Original Instructions Magnetic Pickups and Proximity Switches for Electronic Controls Reference Manual...
- Page 2 Revisions—A bold, black line alongside the text identifies changes in this publication since the last revision. Woodward reserves the right to update any portion of this publication at any time. Information provided by Woodward is believed to be correct and reliable. However, no responsibility is assumed by Woodward unless otherwise expressly undertaken.
-
Page 3: Table Of Contents
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 ... -
Page 4: Warnings And Notices
Start-up To prevent damage to a control system that uses an alternator or battery-charging device, make sure the charging device is turned off before disconnecting the battery from the system. Battery Charging Device Woodward... -
Page 5: Chapter 1. Magnetic Speed Pickups
The MPU may be excited by a keyway or slot in a wheel, but there is likely to be an unwanted background signal due to varying density or eccentricity of the material. -
Page 6: Figure 1-1. Magnetic Pickup Dimensions
The optimum relationship for maximum output is as follows: equal to or greater than D equal to or greater than C equal to or greater than three times D equal to or greater than D Woodward... -
Page 7: Mpu Installation
Manual 82510 Magnetic Pickups and Proximity Switches As the magnetic pickup-gear relationship begins to deviate from the specifications listed above, the MPU output waveform may deteriorate to an unacceptable shape. Because the speed sensor detects zero- crossings, the waveform should cross zero only twice for each tooth (once going positive and once going negative, see Figure 1-2). -
Page 8: Figure 1-3A. Mpu Models
Released Manual 82510 Magnetic Pickups and Proximity Switches Figure 1-3a. MPU Models The surface speed in meters per second (m/s) or inches per second (IPS) is related to revolutions per minute (rpm) by the following: rpm x π x gear diameter... -
Page 9: Figure 1-3B. Csa/Atex Models
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 (ac, rms) at the lowest speed. If you cannot measure the gap directly, it can be determined in the following manner. Woodward... -
Page 10: Figure 1-4. Maximum Air Gap Allowed To Provide Usable Signals For Most Electronic Controls
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 nut securely against the housing or bracket so the pickup cannot turn in or out. Woodward... -
Page 11: Figure 1-5. Maximum Air Gap Allowed To Provide 1.5 V (Ac, Rms) On Egm Control
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. Woodward... -
Page 12: Installation And Operation Safety Requirements
In order to achieve a SIL rating required by an overspeed SIF, the certified versions must be installed in redundant configurations in accordance with the verified parameters of the sensors. See Product Spec Sheet 03474. Woodward will provide the SIL certificate and report for the .SIL versions of these sensors on request. -
Page 13: Troubleshooting Magnetic Pickups
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... -
Page 14: Chapter 2. Proximity Switches
Typical wiring for a “source” type proximity switch is shown in Figure 2-3. The on-off nature of the output of a proximity switch produces a square wave which is compatible with nearly all Woodward speed sensors and will directly replace the signal from a magnetic pickup as a speed sensor input. -
Page 15: Types Of Proximity Switches
Proximity Switch Power Supply Proximity switches provided by Woodward require an external power supply of a single dc voltage, usually 24 volts. This may be from the same supply source as power for the control system. The maximum current rating for these proximity switches is 80 mA, but actual current is less and dependent on the external load. -
Page 16: Checking Proximity Switch Operation
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. - Page 17 Should a remote device be driven by a magnetic pickup, it is important that the connection be made on the governor posts which accept the input from the MPU. Polarity must be maintained as indicated on these posts or it is possible to short the system to ground and cause damage to the electronic circuits, rendering the governor inoperable.
-
Page 18: Revision History
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 Woodward... - Page 19 Released Manual 82510 Magnetic Pickups and Proximity Switches This Page Left Intentionally Blank Woodward...
- Page 20 82510. Please reference publication B82510:V PO Box 1519, Fort Collins CO 80522-1519, 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.
Need help?
Do you have a question about the MPU and is the answer not in the manual?
Questions and answers