Description

Product Description

Control model 9905-144 is a speed control from Woodward’s 2301A series. This control is a low-voltage and forward-acting model. The setting of the actuator potentiometer for voltage is different on the forward acting control than on the reverse; the forward acting controls actuator voltage should be set ten percent higher than whatever the voltage for the rated speed was read at. In reference to the rated speed, preliminary settings for this potentiometer should be set to the absolute minimum; this means the potentiometer will be sitting fully counterclockwise on your control.

 

If using an SPM (speed and phase matching) synchronizer, connect the wires to terminals twenty-five and twenty-six, the positive lead must be connected to terminal twenty-five, and the negative lead must be connected to terminal twenty-six, then using a shielded wire, connect to terminal twenty-seven. It is important to note that the shield should never be connected to the synchronizer. Please advise that the SPM synchronizer is not required for the 9905-144 control to function it is only optional.

 

Be advised that during the operation of the prime mover and the 9905-144 control, if an error occurs, take caution and make an emergency shutdown of the prime mover; doing so prevents property damage and runaway of the prime mover. It is highly recommended that with the operation of the prime mover and control, an external overspeed shutdown device should be used to assist with the shutdown if the prime mover begins to overspeed; overspeeding of the prime mover can result in a runaway and injury.

Frequently Asked Questions about 9905-144

What are the elements needed alongside the 9905-144 control when operating a prime mover?

Other than the 9905-144, when operating a prime mover, a speed-sensing device, such as an MPU, is required, along with an external power source that operates on 10 to 40 VDC or 12 W, and a proportional actuator that will be used to position the steam- or fuel-metering device. All of these elements together allow for the attached prime mover to be controlled without any potential faults or errors occurring.

What is the difference between this model, which is forward acting compared, to a reverse-acting model such as 9905-146?

The main difference between forward-acting and reverse-acting models is that reverse-acting controls can operate additional Woodward models, such as EGB governors or actuators. Another main difference between the two systems is that reverse-acting systems require more fuel when the current on the actuator decreases; if a complete loss of signal occurs on the actuator, the actuator will automatically turn to full fuel. Due to limited information, it can be difficult to find out how the forward-acting models operate, although it should be fairly self-explanatory leading to the lack of information.

9905-144　　2301A　　LV, Forward Acting Speed Contro　　The 2301A Full Authority Speed Control sets the speed or load of a diesel engine, gas engine, steam turbine, or gas turbine according to the demand of a process or a computer control signal of 4–20 mA or 1–5 Vdc.　　FEATURES & FUNCTIONALITY　　The 2301A Load Sharing and Speed Controls are designed for use in electric generator systems where multi-unit load sharing is desired. 2301A controls may be used with diesel, gas or gasoline engines, or steam or gas turbines.　　Applications:　　Requiring droop and/or isochronous speed control　　Either in forward- or reverse-acting models　　In single or tandem actuator installations　　With accelerating or decelerating ramp　　In multiple speed ranges　　Features:　　4–20 mA or 1–5 Vdc full authority speed setting　　Isochronous or droop speed control　　Low- and highvoltage models　　Signal converter included in same control package　　High and low speed adjustments

Start fuel limit with overrideThe 2301A Speed Control controls the speed or load of diesel or gas engines, or steam or gas turbines. The unit provides control in the isochronous mode, with droop available through an externally wired potentiometer. The isochronous mode is used for constant speed of the controlled prime mover as long as it is able to provide power to satisfy the load. The 2301A Speed Control is compatible with Woodward SPM-A synchronizers, load sensors, and other power generation controls. These controls can be added to the system at any time, using the auxiliary or SPM inputs to the 2301A Speed Control. The 2301A Speed Control is available for forward- or reverse-acting applications, and can be used with single or tandem actuators. High voltage models accept 88 to 132 Vac or 90 to 150 Vdc, and low voltage models accept 10 to 40 Vdc supply for control power. 2301A Speed Controls are also available with 4–20 mA speed-setting input (see product specification 02301). Two Set Speeds The control has potentiometer-set Low Idle and Rated Speed settings which are selected with a switch. Description The 2301A Speed Control is housed in a sheet-metal chassis and consists of a single printed circuit board. All potentiometers are accessible from the front of the chassis. Speed range is set by an internal DIP switch inside the aluminum cover of the control. Speeds are based on the frequency of a sensed gear (not necessarily engine rpm). Speed Trim A speed trim potentiometer or digital reference unit may be connected to the control to adjust prime-mover speed from a remote location. Minimum Fuel A switch may be wired to the control to call for minimum fuel to the prime mover. This contact is used for normal shutdown. Failed Signal Circuit The 2301A Speed Control constantly monitors the signal from the magnetic pickup. Should the signal be below a minimum threshold, the control sends a minimum-fuel signal to the actuator. This circuit may be overridden while starting slow-cranking engines. Start Fuel Limit A special circuit in the control provides a limit to the maximum fuel setting while an engine is starting. This feature helps limit exhaust smoke and engine damage. Ramp Times Acceleration time from low idle to rated speed may be adjusted from 1 to 22 seconds. The ramp time from rated to idle is always less than 1 second, regardless of the setting of the ramp-time potentiometer. Reset, Gain, Actuator Compensation Three adjustments are available to permit accurate, responsive engine control. The GAIN control adjusts response time to transient load changes. RESET adjusts the overshoot and undershoot which occurs in response to load swings. ACTUATOR COMPENSATION sets dynamic response time within a 0 to 500 millisecond range to match the time constant of the fuel system. Power Supply 2301A Speed Controls accept either a high- or a low-voltage power source. The low-voltage model operates on 10 to 40 Vdc, and the high-voltage model operates on either 88 to 132 Vac or 90 to 150 Vdc. Speed Range A switch selects one of the following ranges (rating is based on frequency of sensed gear, not engine rpm). 500 to 1500 Hz 2000 to 6000 Hz 1000 to 3000 Hz 4000 to 12 000 Hz Speed Sensing 1 to 30 Vac. Maximum load is 1 k at 1 kHz External Speed Trim ±5% speed adjustment with 100  potentiometer Signal to Actuator 0 to 200 mA, 30 to 45 , standard Temperature Limits –40 to +85 °C (–40 to +185 °F) operating temperature –55 to +105 °C (–67 to +221 °F) storage temperature Humidity Limits 95% at 38 °C (100 °F) Vibration and Shock 4 Gs vibration between 5 and 500 Hz. 60 Gs shock Steady State Speed Band ±0.25% of rated speed Auxiliary Input Allows load sharing accuracy of ±5% of rated load with speed settings matched when using optional load sensing equipment

　Model recommendation:

WOODWARD 9905-969