electric motor help
Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Shops, Barns, Varmints, and Trucks
Forum Description: anything you want to talk about except politics
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=180661
Printed Date: 19 Jul 2025 at 11:15am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: electric motor help
Posted By: jaybmiller
Subject: electric motor help
Date Posted: 21 May 2021 at 6:20am
|
OK, it's too hot here for me to think...... Air compressor(powermate,60g,155psi,3.7rhp) 'died', Century AC motor(4HP, 230x 15), will start, run but NO torque. it stalls/growls when belted to head( head NOT siezed...),belt tension fine. I suspect the 'run' cap even though it 'runs...'. According to manual it's 25mfd/270 yet it says 20mfd . So cap is $189 ! choke, new 3HP motor is $200. 5HP is $350 but need to rewire power... Naturally ,sine the move I can't find my stash of motor caps....grrrrr looking for any advice, options, ??? thanks Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Replies:
Posted By: steve(ill)
Date Posted: 21 May 2021 at 8:52am
|
capacitor might be the problem.. I normally look on e-bay and find one.. Sometimes identical, sometimes CLOSE.. Being off a little on the START capacitor will vary the time ( milli seconds) to get to speed... Not sure what changing the value of the RUN capacitor would do, but probably varies the PHASE ANGLE that would effect the TORQUE.. I though capacitors were about $20 ??? ------------------------------------------ from GOOGLE......... A run capacitor is used to continuously adjust current or phase shift to a motor's windings in an effort to optimise the motor's torque and efficiency performance. Because it is designed for continuous duty, it has a much lower failure rate than a start capacitor.
------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 21 May 2021 at 8:55am
------------- Like them all, but love the "B"s. |
Posted By: plummerscarin
Date Posted: 21 May 2021 at 4:10pm
| What a timely thread to post as I have a sweep auger that runs but won’t start on its own. Have to “kick start” it to operate. |
Posted By: steve(ill)
Date Posted: 21 May 2021 at 4:48pm
|
you need the START capacitor... if will look similar, but very different numbers.. nott 20 UF.... normally 100-200-300 type numbers. ------------- Like them all, but love the "B"s. |
Posted By: JW in MO
Date Posted: 21 May 2021 at 6:53pm
Yours should be under the bubble cover on the side of the motor, it should be black and round. As Steve said, should be something like; 88-108, 108-130, 130-145mfd, and then probably 110vac, 220vac and so on. The larger the vac the larger the diameter usually. ------------- Maximum use of available resources! |
plummerscarin wrote:Posted By: Dusty MI
Date Posted: 21 May 2021 at 7:40pm
|
Single Phase motors have a centrifugal switch that is part of the starting system. I've seen the springs on that switch break. Dusty ------------- 917 H, '48 G, '65 D-10 series III "Allis Express" |
Posted By: HD6GTOM
Date Posted: 21 May 2021 at 9:38pm
| If you get a new motor, make sure it is rated for air compressor use. Farm duty motors don't last very long on a compressor. If you have yours rebuilt, make sure you tell the rebuilder it is for your compressor. Speaking from experience owning a tire shop for 22+ years. |