Eev failure

[COO2]

hi,

i used a ALCO EX6 valve to control the system mass flow. the on-off frequency of compressor is 1circle/2min. when compressor is switched on, the valve should open and functionally control the mass flow;when compressor is switched off, the valve should be closed.
the failure is that sometimes the valve is out of control the mass flow. after reset the valve, the valve is ok.
thanks for your troubleshooting.

[Brian_UK]

You say that the compressor switches on or off every 2 minutes, is that correct ?

If it is then it is a very short time for the compressor and also for the valve to start controlling properly.

[ptsac]

Try the link below for technical info. A digital input can be used to positively shut this valve. If the control input does not revert back to zero the valve may lose its reference. Alco literature explains better.

http://www.ecopeland.com/alcoliterature.cfm?section=alco27