Terminals Are Not Labeled On My Refrigeration System...Now What? ma-51

Technical Questions  

QUESTION:

I have a refrigeration system that used a 1hp Marathon 110v motor that uses a belt to drive a Climatrol open face compressor.  
The motor is CSCR.

The run capacitor has two terminals and is fed with two wires, brown and purple. 
 
Neither terminal is labeled and I can't determine which terminal it to be connected to the EasyStart's orange wire and which is to be which wire is to be spliced to the brown wire. Do you have a wiring diagram for my installation.

ANSWER:

EasyStart has been installed with success into Baldor and Leeson motors of the type you have described (not yet Marathon), but I must advise it is a difficult prospect.

The reason is, even though these motors may be CSCR, as you have already discovered, they don't provide an internal wiring diagram, nor are the wire connections easy to figure out.
Also, there is likely a centrifugal switch that is used to switch in/out the start capacitor. This device typically must also be located and bypassed in order to wire in the EasyStart (depending on the overall design of the motor windings).   

Some motors of the type you describe use dual run windings to handle different voltages, and some also split the start winding with a center tap, applying the start capacitor at one point and the run capacitor at another point. It can get very complicated as compared to the relatively simple task of installing an EasyStart into a HVAC compressor application.

The other challenge is most refrigeration systems are designed to hold their discharge and suction pressures after the compressor shuts down, not allowing them to equalize. This pressure differential during the next compressor startup therefore requires much higher torque than it would if otherwise, thus making the work of any soft starter much more difficult (almost forcing a "hard start" to occur).

Most air conditioning compressors allow the system pressures to equalize during their off time, so the next startup will be less loaded and application of a soft start such as the EasyStart will be much more successful.

In your case, since your refrigeration compressor is belt driven and not direct-drive, that will likely help the starting torque requirement a little bit, but we cannot predict what will happen here and if the EasyStart will work, with any degree of certainty.

In spite of the above points, installing an EasyStart into your refrigeration motor is feasible.
I told you the above not to discourage you, but to make sure you are aware of the challenges this will involve. It could take a fair amount of research and work on your part.

First, I would recommend that you contact the manufacturer of your refrigeration system or Marathon (Regal-Beloit) themselves to see if you can get a copy of their motor's internal wiring diagram - using the model number off of the motor's dataplate label.

We have had good success with other motor manufacturers such as Baldor and Leeson in terms of their willingness to provide internal motor wiring diagrams, but we have little to no experience with Marathon. You may be able to find the diagram online as well.

I just perused the Regal-Beloit website and their Marathon motor subsection, and I was able to find some wiring diagrams for some of the motors listed.
You may get lucky if you search for your motor's model number or can find it in the listing.

Second, after you find the diagram, you can always send to us and we can draw in where the EasyStart will wire and send it back to you. After that, you'll be able to check if all the wire connections that are necessary are accessible, and then make your decision on whether or not to try installing an EasyStart.

 
 
 

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