Usage:
Unpacking
Be careful when unpacking the electronic driver. Check the driver for signs of damage, such as bent or dented panels, scratches, and loose or broken parts. Notify the shipper and Woodward if damage is found.
Mounting
The driver box is designed to operate within an ambient temperature range of -40 to +70°C (-40 to +158°F).
The driver is capable of withstanding the following vibration specifications:
- Shock - US Mil Std 810C, M516.2, PL 40G, 11 mS sawtoothVibration - Random Vibration 0.04 G2/Hz WGC RV2
If the application has a higher vibration level than specified (0.04 G2/Hz), vibration isolators must be used to keep the levels below the given levels.
Mount the driver in a location with space for adjustment and wiring access. Do not expose the driver to sources of radiant heat such as exhaust manifolds or turbochargers. Mount the driver close enough to the actuator and battery to meet the wire length requirements (see wiring requirements in Chapter 6).
The driver will generate some heat, so surfaces must be open to normal air movement. No special ventilation is required.
Ideally, the driver should be mounted flush to the metal side of a control cabinet, protected from the weather and high humidity, and close to the engine being controlled. Do not install the driver directly on the engine. The location should provide protection from high-voltage or high-current devices, or devices which produce electromagnetic interference. After initial adjustments are completed, access to the driver will not be required for normal engine operation.
Actuator Installation - Thermal
The actuators are designed for installation on the engine. The actuators will generate heat, especially when stalled or during other conditions requiring maximum torque output. Maximum operating temperature for the ProAct II actuator is 100°C (212°F).
The installer must consider the heat conductivity of the installation bracket, and the operating temperature of the ultimate heat sink to which the bracket will be attached. Generally the heat transfer abilities of aluminum and low-carbon steel are better than those of high-carbon steel or stainless steel.
Uninhibited air flow over the heat-exchanger fins on the side of the actuators will help control possible heat problems. Keep the fins as clean as possible to improve heat transfer. Do NOT paint the fins, since this will reduce the heat transfer efficiency.
If operating temperature is a concern, contact Woodward for more information.
Fuel Position Stops
Diesel Stops. Diesel installations will generally use the fuel system minimum and maximum position stops. Diesel engine racks are normally designed to provide the minimum and maximum stops without binding.
The actuator's stops must not prevent the actuator from driving the fuel linkage to the minimum and maximum positions. The linkage should be designed to use as much actuator travel as possible, without preventing minimum and maximum fuel positions (see Figure 3-1).
Gas Engine Stops. Butterfly valves in carburetors will often bind if rotated too far toward minimum or maximum. For this reason, the stops in the actuator should be used at both minimum and maximum positions. Note that the stops will allow up to 3 degrees of additional rotation in both directions during impact (see Figure 3-2).
The engine must always shut down when the actuator is at the minimum stop.
2 CAUTION: The actuator's maximum slew rate can place stress on fuel system stops and on the linkage between the actuator and the fuel system. Maximum actuator speed is 900 degrees per second in both the increase and decrease fuel directions. The ProAct II actuator's Mass Moment of Inertia (MMOI) is 0.062 in-lb-sec.
ProAct II actuator stops are designed to absorb 1.1 J (10 in-lbs) of kinetic energy with 3 degrees overtravel. If the actuator travel stops are used, the linkage must be designed to allow this 3 degree overrun.
Use good rod-end connectors with as little free play as possible. Select rod ends which will not become loose and which will wear well during the nearly constant movement associated with precise speed control. Low-friction, long-wearing rod ends are available from Woodward.
The link connecting the actuator lever to the fuel-control lever must be short or stiff enough to prevent flexing when the engine is running.
Figure 3-1. Diesel Engine Travel Stops
Figure 3-2. Carburetor Travel Stops
Actuator levers are available from Woodward which will allow adjustment of the rod-end location with respect to the center of the actuator shaft. The lever used must have the correct interface for the actuator used.
Adjust the location of the rod end on the lever to achieve the desired rotation of the actuator shaft between minimum and maximum positions. (Use as much of the 75-degree rotation as possible - at least 60 degrees.) To increase the amount of rotation, move the rod end closer to the actuator shaft or farther away from the shaft controlling fuel flow. To decrease the amount of rotation used, move the rod end farther from the actuator shaft or closer to the shaft controlling fuel flow.
Actuator Bracket
The actuator may be installed on a bracket which attaches to the base with four M8x1.25 (0.312-18) screws with a minimum engagement of 16 mm (0.625 inch). The actuator may be mounted in any attitude. The actuator is weatherproof and resistant to the corrosive effects of water and salt water. Avoid pressure washing near the shaft seals.
The ProAct II actuator weights 6.9 kg (15.23 lbs). The bracket and attaching hardware must be designed to hold the weight and to withstand the vibration associated with engine mounting. The bracket must also be designed to provide a heat sink (heat transfer) from the actuator to the engine block. Figure 3-3 provides an illustration of the mounting bracket.
Figure 3-3. ProAct II Mounting Bracket
Electrical Connections
External wiring connections and shielding requirements for a typical control installation are shown in the plant wiring diagram (Figure 1-4).
The type and gauge of the wiring used should follow the wire length and type shown in the System Wiring section of Chapter 6.
Shielded Wiring
All shielded cable must be twisted conductor pairs or triples. Do not attempt to tin the braided shield. All signal lines should be shielded to prevent picking up stray signals from adjacent equipment. Connect the shields to the correct pins on the driver connector or wiring. Do not connect shields to the actuator ground. Wire exposed beyond the shield should be as short as possible, not exceeding 50 mm (2 inches). The other end of the shields must be left open and insulated from any other conductor. DO NOT run shielded signal wires along with other wires carrying large currents. See Woodward application note 50532, Interference Control in Electronic Governing Systems, for more information.
Where shielded cable is required, cut the cable to the desired length and prepare the cable as instructed below (Figure 3-4).
Figure 3-4. Preparing Shielded Wiring
1. Strip outer insulation from BOTH ENDS, exposing the braided or spiral wrapped shield. DO NOT CUT THE SHIELD.
2. Using a sharp, pointed tool, carefully spread the strands of the shield.
3. Pull inner conductor(s) out of the shield. If the shield is the braided type, twist it to prevent fraying.
4. Remove 6 mm (1/4 inch) of insulation from the inner conductors.
The shield must be considered as a separate circuit when wiring the system. The shield must be carried through connectors without interruption.
Installations with severe electromagnetic interference (EMI) may require additional shielding precautions. Contact Woodward Governor Company for more information.
Failure to provide shielding can produce future conditions which are difficult to diagnose. Proper shielding at the time of installation is required to assure satisfactory operation of the ProAct control system.
Power Supply
Power supply output must be low impedance (for example, directly from batteries).
Run an insulated wire directly from the positive (+) battery terminal to the fuse and the switch as shown in Figure 3-5, then from the switch to the correct connection on the driver (see Figure 1-4). Run a second insulated wire directly from the negative (-) terminal of the battery to the driver. Neither of these connections need to be shielded (see Figure 3-5 for correct installation).
Run the power leads directly from the power source to the control. DO NOT POWER OTHER DEVICES WITH LEADS COMMON TO THE CONTROL. If the power source is a battery, be sure the system includes an alternator or other battery-charging device (see Figure 3-6 for incorrect installation).
When the engine is shut down, the driver powers the actuator to the minimum stop. If the battery charging system is off when the engine is shut down, this will cause the battery to be drained. In this case, the power to the ProAct must be turned off with a switch or relay. Any such switch or relay must be interlocking to prevent starting the engine when power to the actuator is shut off.
Figure 3-5. Correct Wiring to Power Supply
Figure 3-6. Incorrect Power Supply Wiring
Do not use the driver for normal shutdown procedures. All actuator position commands should come from the control unit, through the driver, to the actuator.
CAUTION: To prevent possible damage to the control, or poor control performance resulting from ground loop problems, follow these instructions.
It is important to set up the ProAct driver in the order that follows. See Figure 3-7 for the location of potentiometers on the driver box.
CAUTION: Always hold onto the side of the control box with one hand while making an adjustment with the other hand. This prevents possible static damage to parts.
Use an insulated screwdriver to make adjustments. Extensive damage is possible should the high voltages present inside the box be shorted to elements on the board.
Figure 3-7 ProAct Driver Adjustment Locations
Position Feedback Adjustment
The driver's position feedback Gain and Offset adjustments normally don't need to be changed unless you experience feedback values outside the normal operating parameters of the driver. If the characteristic falls outside the tolerance limits, adjust System Position FB Gain and Offset as required to get the characteristic midway between the tolerance limits (see Figure 3-7 for adjustment locations).
The procedure for adjusting the system position feedback is as follows.
To set up the driver system feedback, first disconnect the actuator drive wires at the control (DO NOT disconnect the actuator position feedback wires). Power up the system with the actuator disconnected from the linkage but with the inertia disk in place. DO NOT START THE ENGINE AT THIS TIME.
The actuator can be manually moved between minimum and maximum fuel, based on actuator stops. Adjust the System Position FB (feedback) Gain and Offset potentiometers until the output at the terminals is within the desired specification. The nominal voltages are 0.5 V at minimum fuel and 4.5 V at maximum fuel.
NOTE: The adjustment of the system position feedback potentiometers does not affect the positioning of the actuator relative to the position input signal, or the response of the actuator to the position input signal.
Reconnect the actuator drive wires.
Actuator Travel
The driver's Gain and Offset adjustments normally don't need to be changed unless you experience difficulty getting the actuator to travel full stroke. If the characteristic falls outside the tolerance limits, adjust Position Command Gain and Offset as required to get the characteristic midway between the tolerance limits (see Figure 3-7 for adjustment locations).
To set up the driver and actuator, power up the system with the actuator disconnected from the linkage but with the inertia disk in place. DO NOT START THE ENGINE AT THIS TIME.
Vary the signal into the position input to the driver and observe actuator angle. Adjust the Position Command Gain and Offset potentiometers to achieve the desired relationship (see Figure 3-7). Failure to make this adjustment correctly may result in the inability to shut off fuel or the inability to reach full-fuel position. After this adjustment is made, re-install linkage, coupling, etc., to the engine.
This procedure must be repeated whenever the actuator or driver is changed. The Gain and Offset pots are both located on the printed circuit board inside the driver box.
The actuator position feedback sensor is factory set and should not be adjusted.