Flowserve 10-40 39 Access M Worcester Controls - Manual (Page 8)

8 10-40 39 Access M Mounted Limit Switch (Proximity Sensor) and Solenoid WCAIM2034
Flow Control
Worcester Controls
The actuator is electrically fail-safe. That is, it will return to its
de-energized position upon electrical failure.
The unit has two independently adjustable speed control
screws which can be used to adjust the speed of operation for
the opening and/or closing stroke (see Figure 2 on page 9). If
the speed control screws are too tight, the unit will fail to
operate.
NOTE: Speed control screws are shipped from the factory in the full-
open position.
B. Spring-Return with Control Block - Air is supplied to the 1 /
4
"
NPT port on the block. When the solenoid is energized, the
spring-loaded plunger is withdrawn, allowing the supply air to
shift the spring-loaded spool within the block, which opens
the supply path to the center chamber of the actuator. Air
from the end chambers of the actuator is allowed to pass
through the block and exhaust to atmosphere.
When the solenoid is de-energized, the spring-loaded plunger
blocks the flow of air to the spool within the block and the
spring-loaded spool returns to a position which allows air
from the center chamber of the actuator to pass through the
block and exhaust to atmosphere as the actuator is cycled by
the springs in the end chambers of the actuator. The end
chambers are exhausted to atmosphere at all times.
The actuator is fail-safe. That is, it will return to its de-
energized position upon electrical or pneumatic failure.
The unit has one speed control screw, which can be used to
adjust the speed of operation for the closing stroke (on a fail-
closed unit) or opening stroke on a fail-open unit, and one
port plugged with a red plastic plug (see Figure 2 on page 9).
If the speed control screw is too tight, the unit will fail to
operate.
NOTE: Speed control screws are shipped from factory in the full-open
position.
CAUTIONS: If converting a double-acting actuator to a spring-return
actuator or vice-versa, be sure the correct control block gasket is
used (see Figure 1 on page 9 and Access exploded view).
Be sure red plastic plug is installed in plugged port (Figure 2 on
page 9) for spring-return actuators.
C. Double-Acting with No Solenoid and No Control Block - Air is
supplied to the 1 /
4
" NPT port on the air connection block to the
center chamber of the actuator through a remotely mounted
four-way solenoid (or similar supply system). The other
1 /
4
"
NPT port on the air connection block to the end chambers is
exhausted through solenoid (or similar supply system). When
solenoid is de-energized (energized) supply air is now
supplied to end chambers and center chamber is
simultaneously exhausted through solenoid.
D. Spring-Return with No Solenoid and No Control Block - Air is
supplied to the 1 /
4
" NPT port on the air connection block to the
center chamber of the actuator through a remotely mounted
solenoid (or similar supply system). The other
1 /
4
" NPT port on
the air connection block is the exhaust port for the end
chambers and may be exhausted to atmosphere or through
customer’s system.
When the remotely mounted solenoid (or similar supply
system) blocks the supply air to the center chamber of the
actuator, a means must be supplied to exhaust this chamber
and the actuator is cycled by the springs in the end
chambers.
E. Manual Operation
In the event of air failure, the Series 39 actuator with Access
unit can be cycled manually. This is accomplished by applying
a wrench to the exposed top shaft of the actuator and turning
it in the desired direction.
WARNING: Care must be taken to ensure that the actuator is not
operated automatically while manual operation is being performed.
If a routine cycle check is to be performed on an actuator
with a control block, the actuator can be cycled manually by
shifting the spool valve within the control block. This can be
done by pushing the override button in the control block (See
Figure 2 on page 9 for location of button). Care must be taken
to hold the spool valve in the desired position until the
actuator has cycled. Provided the air supply is still on, the
actuator will cycle to its original position as soon as the
manually applied pressure on the override button is released.
F. If the actuator does not function, see troubleshooting section
in actuator Instruction Manual and if necessary, check circuit
board for a blown fuse (F1) (120 VAC units only). Using an
ohmmeter, the fuse should read about 6 ohms if it is good.
Remove the fuse from the circuit board in order to check it. If
it is good, reinstall the fuse. If the fuse is bad, replace it with
a Littlefuse PICO II very fast-acting fuse rated at 62 mA
(Newark part number 94F2146) or the spare fuse, which may
be found on some circuit boards and located below capacitor
C1. Try to determine what caused the fuse to blow before
turning power back on. The most likely cause is a bad
solenoid coil.