Fault Location - Danfoss EV210B How To Use Manual

Symptom:
Probable cause
No voltage on coil
Incorrect voltage/frequency
Coil burnt out
Diff. pressure too high
Diff. pressure too low
Damaged/bent armature tube
Dirt at diaphragm
Dirt in valve seat/dirt in arma-
ture/armature tube
Corrosion
Components missing after
valve dismantling
© Danfoss A/S (IA-MC/mhe) 05-2007 / 520B2809
Solenoid valve does not open
Remedy
Check whether valve is de-energised open or closed (NO
or NC):
1. Use a magnetic detector
2. Lift coil slightly and note whether it offers resistance
against lifting
Note: Never remove a coil with voltage applied - it may
burn out.
Check relay contacts. Check lead connections. Check
fuses.
Check to make sure the coil's electrical requirements are
the same as the installation supply. Measure the opera-
ting voltage at the coil. Permissible voltage variation:
±10% for dual frequency; dc and NO applications
+10% / -15% for ac on single frequency voltages
If necessary, replace coil with correct version.
See page 29
Check coil data. If necessary, replace coil with correct
version.
Reduce differential pressure, e.g. by limiting inlet pres-
sure.
Check coil data and differential pressure. If necessary,
replace coil with correct version.
Replace valve
2) Clean diaphragm. If necessary, replace defective
component(s)
Clean valve; if necessary, replace defective component(s).
2)
Replace defective component(s)
Fit missing component(s)
1) .
1) .

Fault location

1)
25