Dunham Bush Chiller

[iceman007]

I don't suppose anyone would have a wiring diagram on computer for a Dunham Bush Chiller ??

Even the identification plate is missing from this one. All I know is it has 2 Refcomp compressors (I just rebuilt one of them) and have to change from star delta to part winding start,

Cheers

[LRAC]

Hi Iceman007

Try this site the electrical diagrams are always at the bottom of the PDF's

http://www.dunham-bush.com/dls.html

Converting to part wind shouldn't be a problem, you probably know this but what the hell. measure the resistance of the windings and check that 1 set of windings does not read higher than the other set if they do the compressor might be a 60/40 split, if they do read the same its a 50/50 split so it doesn't matter which set of windings activate first. As usual add a timer set to secounds to bring in the secound set of windings after the first has activated.Remove the third spare contactor and you should be ok, unless the secound set of windings try to start in the oposite direction?

Kind regards
Lrac

[Sledge]

How do you make sure that it is not starting in the wrong direction?

On a motor, where the shaft is visible, I would run the motor unloaded on one set of windings, then run it on the other set, and make certain that they are running in same direction. I am thinking that I would do the same thing on a compressor, only this would require pulling the head. Is there another way?

I have never seen a motor with 2 sets of windings, where they were not the same? 60/40 split? Didnt know that you could buy that. I am not sure if that will make a big difference...but am thinking that I would want to start on the 60% winding first.

[LRAC]

How do you make sure that it is not starting in the wrong direction?

I have never seen a motor with 2 sets of windings, where they were not the same? 60/40 split? Didnt know that you could buy that. I am not sure if that will make a big difference...but am thinking that I would want to start on the 60% winding first.

Hi Sledge follow the link below and download the compressor field guide it has quite a lot if info that explains partwind compressors.
http://www.thermagroup.com/compressors.php

Kind regards
Lrac

[Sledge]

Hi Sledge follow the link below and download the compressor field guide it has quite a lot if info that explains partwind compressors.
http://www.thermagroup.com/compressors.php

Kind regards
Lrac


Great link, Didnt realize there were so many compressor manufacturers.

Thanks:)

[iceman007]

Hi Iceman007

Try this site the electrical diagrams are always at the bottom of the PDF's

http://www.dunham-bush.com/dls.html

Converting to part wind shouldn't be a problem, you probably know this but what the hell. measure the resistance of the windings and check that 1 set of windings does not read higher than the other set if they do the compressor might be a 60/40 split, if they do read the same its a 50/50 split so it doesn't matter which set of windings activate first. As usual add a timer set to secounds to bring in the secound set of windings after the first has activated.Remove the third spare contactor and you should be ok, unless the secound set of windings try to start in the oposite direction?

Kind regards
Lrac

It's a 50/50 motor. What I am doing is taking the timer down (to half a second or so). I can't do much with it until the BMS people have been out as there are problems enabling it. I will put the first timer into A1 on the first coil and take a lead from a set of contacts (normally open) through the time delay to the second contactor.

Cheers