Danfoss EV210B - Page 17

15
IC.PS.600.A4.02 / 520B2809
© Danfoss A/S (IA-MC/mhe) 05-2007 / 520B2809IC.PS.600.A4.02 / 520B2809
Filter
In systems with contaminated media there is a risk of moving parts in a valve
not working as intended. Dirt is the most common cause of function failure in
solenoid valves. To help avoid this problem we suggest the tting of a lter on
the upstream side of the valve.
Coil voltage and power
It is necessary to know which voltage (Volt a.c./d.c. nominel ± 10%) is available
within an application to select the correct coil. The maximum permissible
dierential pressure can also be increased by tting a more powerful coil.
The coil power depends on the type of coil (BA,BB,AC,AM etc.)
Other environmental factors
In wet or very humid environments, coils with IP 67 enclosure classication must
be used.
Valve function
Most industrial systems operate with a de-energised closed valve (NC = normally
closed). Our valve range also oers de-energised open valves (NO = normally
open) for applications requiring this feature.
How to Choose
Water hammer
All piping systems with relatively high ow rates are susceptible to water ham-
mer when a valve is opened or closed. A damped solenoid valve ( eg. EV220B
15-50) should be used if there is a risk of water hammer. After installation the
valve can be adjusted for water hammer by changing a replaceable equalising
orice. See "Spare parts"