Elec
trical
6 - 7
Electrical
EP800AD (Acrobat™ HPU)
Service and Repair
Proportional Pressure Reducing Valve (PRV) Solenoid
The PRV solenoid is used to magnetically control the spool of the PRV
valve. It is driven by a digitally controlled PWM power driver inside the
valve controller and is otherwise non-serviceable.
NOTICE:
The valve controller is programmed from the factory and the
software and hardware are not field serviceable.
The valve controller can usually detect a fault in the solenoid and
will blink its module status light red (fast, 0.25s on, 0.25s off)
The resistance of the solenoid may be checked and should be 18
(± 5) Ohms. If the resistance is less this indicates a shorted fault,
if the resistance is more an open fault.
Open/Close Solenoids
These solenoids work in much the same way as the PRV solenoid except
they are not proportional. They are simply fed 24V from the Open/
Close switch.
The resistance of the solenoid may be checked and should be 34
(± 5) Ohms. If the resistance is less this indicates a shorted fault,
if the resistance is more this indicates an open fault.
If the resistance is OK and voltage is present at the solenoid’s
wire plug the solenoid may be checked by removing the solenoid
from the valve stem and placing a screwdriver or metal object
through the middle. If the solenoid is on you should feel a
magnetic field holding the screwdriver in place, this indicates that
the solenoid good and attempting to actuate the spool.
Ω
18
.
0
Ω
34
.
0
Open/Close Solenoids
Proportional Pressure
Reducing Valve Solenoid
