Nc Function; Troubleshooting; Replacing Solenoid; Replacing Diaphragm - Beko DRYPOINT AC Series Installation And Operating Manual

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7.5.3. NC function

Closed:
The pressure spring in the magnet armature closes the pilot seat.
The diaphragm is pushed by a closing spring onto the main valve seat.
The process fluid flows through the control bore in the diaphragm into the control chamber above the diaphragm,
thus increasing the closing force.
Open:
After the electric power is switched on, the magnet armature is pulled by magnetic force against the pole surface of
the magnet sleeves.
The pilot seat is now open and the fluid pressure in the control chamber is reduced, as fluid is released through the
valve. The amount of fluid escaping from the control chamber through the pilot seat is greater than the amount that
flows into the chamber through the control bore in the diaphragm. A pressure difference is established, lifting the
diaphragm so that the main valve seat is opened.

7.5.4. Troubleshooting

Symptom
Valve failure
Valve seat not tight

7.5.4.1. Replacing solenoid

Shut down the power supply. Loosen the central screw of the device socket and remove the socket.
Disengage the spring bracket and remove the solenoid. If the O-ring on the magnet sleeve has become brittle,
replace it.
Place the new solenoid on the sleeve so that the spring bracket engages in the groove. Push in the spring bracket
to engage it properly. Turn the solenoid into the desired position and mount the device socket with the seal.
Tighten the central screw of the device socket with max. 60 Ncm.

7.5.4.2. Replacing diaphragm

Depressurise the valve and shut down the power supply.
Disengage the spring bracket and remove the solenoid.
Loosen the screws of the cover and remove the valve cover. Remove the pressure and the diaphragm.
Install the new diaphragm on the valve housing as shown in the drawing. Mount the valve cover and tighten the
cover screws crosswise.
Tightening torques for screws
M4 = 2.0 Nm±10 %
M5 = 3.6 Nm±10 %
M6 = 6.0 Nm±10 %
M8 = 16.0 Nm±10 %
M10 = 31.0 Nm±10 %
DRYPOINT AC 410 – 495 | DRYPOINT
®
Possible cause
Fuse loose or tripped
Solenoid defective, no flow
Operating pressure too high
Crack in diaphragm
Valve dirty
Magnet armature blocked
AC 410 – 495 MS
®
Installation and operating manual
Remedy
Control voltage must be > 90 % of the
rated voltage. If the operating voltage
is low and the power cables are long,
choose a large conductor cross-section
to minimise the voltage drop. Measure
the control voltage just in front of the
solenoid.
Check fuse.
Replace coil.
Check max. operating pressure and
reduce, if necessary.
Replace diaphragm.
Clean control bores.
Clean magnet armature and sleeve.
Clean valve; if the seat area is heavily
contaminated: replace diaphragm.
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