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SkyWalker
19-10-2010, 06:46 PM
hi guys just a quick one (I hope) are pressure transducers ever used on the safety side of a system? like LP or HP? I can understand them being used for control but not really safety.

strange question as I don't think I have come across any on the safety side of things just wondered really.

cheers techs!!

Grizzly
19-10-2010, 08:01 PM
Yep. they are used a lot on chillers but there is usually a higher setting protected by a actual mechanical switch.
Grizzly

Quality
19-10-2010, 08:03 PM
Yep. they are used a lot on chillers but there is usually a higher setting protected by a actual mechanical switch.
Grizzly

Can not beat the mechanical stuff:D:D :D

Brian_UK
19-10-2010, 11:02 PM
You'll probably find that somewhere it is written that safety switches shall be mechanical.

Most likely in an insurance policy I expect.

Magoo
19-10-2010, 11:53 PM
I service alot of ammonia systems where transduces are intergrated into micro processors controls, no mechanical lockouts. But vessels etc., protected with dual safety releif valves.

SkyWalker
20-10-2010, 08:30 PM
thanks guys, this raises a final question in that if a transducer was used for LP how could we bypass this for pump down?

the logical answer off the top of my head would be to wire up a resistor to fool the unit into thinking there is constant pressure and take the transducer out, but this would raise the issue of what resister do we use/carry on the van

is there an easier way?

VRVIII
20-10-2010, 09:01 PM
thanks guys, this raises a final question in that if a transducer was used for LP how could we bypass this for pump down?

the logical answer off the top of my head would be to wire up a resistor to fool the unit into thinking there is constant pressure and take the transducer out, but this would raise the issue of what resister do we use/carry on the van

is there an easier way?

Hi,

Most manufacturers provide a pump down option in the controller software but locating it can be different story:rolleyes:

You could always disconnect the transducer and connect it to a bottle of refrigerant or OFN. But take care as some scroll compressors can be damaged when operating with very low suction pressures less than 15psi.

SkyWalker
24-10-2010, 09:55 AM
cheers guys appreciate it :)