3 phase motor controller


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Old 09-06-21, 08:59 AM
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3 phase motor controller

Quincy 15 HP air compressor, Cutler -Hammer CE15HN3 magnetic controller with over load device. I cleaned contacts, reassembled, inspected overload switch, no visual burning or damage, tested everything with ohm meter. Wired to a 3 phase test pigtail on bench and energized the magnetic connector does not move. the coil ohms reads 101.5 open or closed. Question should the magnetic switch close when energized? When controller was still connected to compressor I manually pushed in switch and the motor did not turn but a loud electrical surge sound occurred. It did not sound good.
Thanks for any help.
 
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Old 09-06-21, 09:52 AM
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Welcome to the forums.

The magnetic starter won't engage. That uses a two wire coil. You need to make sure you give it the voltage it requires. It doesn't always use the same voltage as the motor.

Are you using the required voltages ?
 
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Old 09-08-21, 03:39 PM
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I got pictures but don't know how to upload them. I will measure voltage this weekend. I beleave the coil is a 220 V. The ohms reading across the coil is 101.5. Would this be a good number?
 
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Old 09-08-21, 03:59 PM
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Old 09-08-21, 07:27 PM
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Make the pictures a little bigger. 600x600 is a pretty good size.
 
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Old 09-17-21, 11:15 AM
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Hello PJmax and fellow members.

I will be concluding this thread today because I found the problem and fixed it.
Quick summery: Rebuilt contactor, cleaned up contact points, removed cover on overload relay, examined, blew out dust but did not touch because everything looked good. reassembled all parts.

Ohms tested everything, all passed, hooked up 3 phase 30 A pig tail and volt tested all was good but had to manual push contactor to close.

Ohms tested motor windings all good, ground tested all windings all good. Had enough #6 THHN in stock to direct connect motor to disconnect switch and motor roared to life.

Reinstalled contactor and relay. Volt tested while energized and discovered the following. 120V-240V- 85V.

There it is. found a 120V leg at a Polaris tap somewhat shorted but not burnt in half.

Ripped out all conduit, #8 wire and the J-box, replaced with all new conduit and wire. Problem solved.

This experience proves total lack of maintenance on my part and this winter I will maintain the entire compressor, motor, pilot switch and silver solder the contactor points.

I have a question. Is there a solvent I can spray directly into the motor now to clean grease and dirt build up on windings with out damaging in any way. Don't want to dissolve varnish or what ever and short motor.
 
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Old 09-17-21, 06:03 PM
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Almost every chemical company has a motor cleaner. You can do a general search to locate them.

I use CRC LectraMotive cleaner. Works good. One vendor...... CRC 05018 at amazon

Grainger also offers a good cleaner.
Spray-On offers EL703 which is an excellent cleaner.
 
 

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