ADC225 Series Manual

ADC225 Series Manual

INTRODUCTION
The 225 Series electric actuator is a rotary output, linear torque,proportional servo. This electromechanical actuator is typically used as an engine
fuel control positioning device.An internal spring provides fail safe operation by forcing the actuator to the fuel shut off position when the actuator
is de-energized. This design combines fast operation,
multi voltage usage, wider rotation angles, and proven reliability. The actuator can operate directly from 12, 24, or 32 volt battery supplies.
The speed of operation of the actuator is typically faster than competitive units, thus it provides more stable and rapid response to transient
conditions.Applications include most block pumps, with or without mechanical governors, distributor type pumps, and medium sized carbureted
engines. The 25 degrees of rotation expands the application to a wider variety of engines.

DESCRIPTION
The actuator is an electromagnetic servo device which can be integrated into a closed loop control system. An engine control system can be described
as follows.An electrical signal is generated by a magnetic speed sensor which is proportional to engine speed. This signal is sent into the electronic
speed control unit which compares it to the preset engine speed setting. If the magnetic speed sensor signal and the preset engine speed setting are
not equal, a change in current from the speed control unit to the actuator will change the magnetic force in the actuator.

The rotation of the actuator shaft will then adjust the fuel to the engine and cause the engine speed to be equal to the preset engine speed setting.
Shaft rotation is proportional to the amount of actuator current and counterbalanced by the internal spring.Since the design has no sliding parts and
is totally sealed,outstanding reliability results. A single compression spring is used to improve reliability. No maintenance is necessary.




SPECIFICATIONS

PERFORMANCE
Available Torque....................See Diagram2...................... ......Max 2.2 Ib-ft (2.7 Nm)
Maximum Operating Shaft Angular Travel...........................25土1 degree CW/CCW
POWER INPUT
Operating voltage............................................................................12, 24, or 32 VDC
Normal Operating Current.....................................................................3A at 12 VDC
............................................................1.5 A at 24/32 VDC
Maximum Current-Continuously Rated................................8Aat 12 VDC, 9 A for HOS
.............................................4A at 24/32 VDC
ENVIRONMENTAL
Temperature Range.................................................-65to +200° F (-54° to +95* C)
Relative Humidity........................................................................................up to 100%
All Surface Finishes.............................................. Fungus proof and corrosion resistant
PHYSICAL
Dimensions..............................................................................................See Diagram 1
Weight ...............................................................................................8.25 lbs. (3.75 kg) .
Mounting.................................Any position, electrical connector at the top preferred
RELIABILITY
Vibration........................................................................................upto20G@50-500Hz.
Testing........................................................................................................ 100% Tested




INSTALLATION

The actuator must be rigidly mounted as close as possible to the fuel control lever of the engine. Vibration from the engine will not affect the
operation of the actuator. The preferred mounting is with the electrical connector at the top. Applications with the actuator upside down,
on its back, or sideways should be avoided. Linkage arrangement of any actuator system is always important. High quality rod end bearings
should be used.Rod end bearings that have high friction can cause instability and require servicing. Levers and linkage should be sturdy yet
low in mass for the fastest speed of response conditions.Arrangement of the linkage for actuation of the engine fuel control is an important application
consideration. For proportional actuators to operate with linear control systems, it is important to obtain a linear relationship between actuator stroke and
fuel delivery.The linkage configuration for diesel fuel systems is typically as illustrated in Diagram 3. The lever on the actuator should be nearly parallel to
the pump lever at the mid fuel position for linear fuel control.For proportional actuators to operate with non-linear systems, it is important to obtain a non-linear
relationship between actuator stroke and fuel delivery.Carbureted, PT Pumps (CUMMINS), or other non-linear fuel systems require a non-linear fuel linkage 
configuration as illustrated in Diagram 4. A non-linear fuel system results when more engine power is developed for a given stroke at positions of low fuel settings
than at high fuel settings. In this case the levers should be parallel at full load.In general, the linkage should be adjusted so that the fuel control lever minimum and
maximum fuel stops are used rather than the actuator internal mechanical stops.
The actuator should be adjusted so that it operates over at least one half (12 degrees) of its available travel.