Chiller/EEV

[tec man]

Whats a good way to test a exv to see if is working ok.
thanks Herman

[HJ Controls]

check discharge superheat or suction superheat depending on chiller. then load up chiller, and watch and see if exv maintains proper superheat.
just say your discharge superheat is low like 15 degrees and you exv position is at the bottom range. This would be a good sign that the exv is probably sticking. Keep it simple the exv should maintain proper superheat. If in doubt pull it apart and in service mode run it from 0-100 steps. You can also ohm the windings, feel the pulsation as it drives up and down.

Better yet get the service manual for the machine your working on and use the guide lines.

Hope this helps

[klove]

check discharge superheat or suction superheat depending on chiller. then load up chiller, and watch and see if exv maintains proper superheat.
just say your discharge superheat is low like 15 degrees and you exv position is at the bottom range. This would be a good sign that the exv is probably sticking. Keep it simple the exv should maintain proper superheat. If in doubt pull it apart and in service mode run it from 0-100 steps. You can also ohm the windings, feel the pulsation as it drives up and down.

Better yet get the service manual for the machine your working on and use the guide lines.
Hope this helps

The highlighted portion of this quote and personal experience are the only sure things you have. Some run at 4 degrees, some at 15 degrees (superheat), some in between, depends on machine and application. Some don't do steps or have windings, others do, some you can pull apart, others you can't, some have service mode and some don't, all depends on manufacturer. Get the service info on what you have and use that as your guide.

[ryan1088]

Agreed with everything so far....might be helpful for you to tell us what you are working on and why you are wanting to test the valve?

[HJ Controls]

read the last part, get service manual. trying to give helpful hints and some ideas.

[ESS CHILL WATER]

definitively you need the IOM manual of the unit , is different with every brand
different method of test
with model and serial of the unit may be we can share the manual

[jcistc]

Check the actuator. Sometimes the inputs are fine but the actuator is not. Consider it like a jammed actuator. Actuator is the thing that moves the orifice plate according to superheat conditions.

[klove]

Check the actuator. Sometimes the inputs are fine but the actuator is not. Consider it like a jammed actuator. Actuator is the thing that moves the orifice plate according to superheat conditions.

It's wise to refrain from giving advice if you don't know what you're giving advice about.......

[jcistc]

It's wise to refrain from giving advice if you don't know what you're giving advice about.......

i have seen this problem . the chiller would just not reach rated capacity. every thing was fine .. we even checked for leakages , but there were none. then it was found that the orifice plate actuator travel was faulty. It was getting jammed .


maybe what i am speaking about - the thing that connects the stepper motor and the orifice plate - is not an "actuator" .

[klove]

i have seen this problem . the chiller would just not reach rated capacity. every thing was fine .. we even checked for leakages , but there were none. then it was found that the orifice plate actuator travel was faulty. It was getting jammed .


maybe what i am speaking about - the thing that connects the stepper motor and the orifice plate - is not an "actuator" .

How do you know you've seen the problem the OP's having? He didn't give the least bit of info about what type or make chiller it is, or the manufacturer of the valve. It's impossible that you can give specific advice of any kind on this matter.

[HJ Controls]

an exv is an exv. It has a motor, windings, some type of guide a orfice of some type and it recieves a signal or voltage to operate from a controller or source. And we are trying to help him with the info he gave us.
It is a given that he reads the iom for a perticular unit or he is just asking a general question.

[jcistc]

OK i'll have to admit that my reply was very very specific.

[klove]

an exv is an exv. It has a motor, windings, some type of guide a orfice of some type and it recieves a signal or voltage to operate from a controller or source. And we are trying to help him with the info he gave us. It is a given that he reads the iom for a perticular unit or he is just asking a general question.

Then the first thing that should have been stated is that there wasn't enough info given to be able to give any real direction. Otherwise, I think you should explain the operation of every EXV by every different manufacturer that's on the market today 'cause I've got news for you - an EXV ain't an EXV except in very general terms. Some are close to others, but that's about as far as it goes. Service procedures can be totally different from one brand to the next. The only advice given that was credible (based on the question as asked) was to run the chiller and see if it holds it's superheat setpoint, and to get the literature on the valve/chiller and see how it's supposed to work. Past that was nothing more than shootin' in the dark. Ryan actually stated the obvious about what's needed.

I didn't realize that it's a given that he's reading the IOM. Per your first post, neither did you.

Now to the crux of the issue: HERMAN - if you'll tell us what you're trying to accomplish and give some specifics as to what you're working with, maybe someone can help get you going in the right direction. If you're just asking in general out of curiosity, then you can take all of the advice that's been given so far as different things that can happen depending on whose valve you're dealing with (but let us know that this is what you were asking for so we can quit wondering).

[klove]

OK i'll have to admit that my reply was very very specific.

Hindsight's 20/20, and I've had to check mine far too often!