ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Recall Notice Kidde Smoke Alarms
by dougwells. 03/22/18 01:40 PM
by HotLine1. 03/22/18 09:08 AM
Recall notice: Southwire wi-fi wall switches
by sparkyinak. 03/15/18 06:03 PM
Goodman Manufacturing Recalls Modular Blowers
by Admin. 03/13/18 10:40 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 26 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
AC Motor Maintenance (3phase/1phase) #162354
04/18/07 03:44 AM
04/18/07 03:44 AM
roland12  Offline OP
New Member
Joined: Apr 2007
Posts: 2
hi guys! pls help me
how can i maintain a 3 phase/1 phase motor
preventive / corrective if any.
thanks in advance.

Tools for Electricians:
Re: AC Motor Maintenance (3phase/1phase) [Re: roland12] #163214
05/04/07 01:36 AM
05/04/07 01:36 AM
RODALCO  Offline
Joined: Dec 2005
Posts: 856
Titirangi, Akld, New Zealand
Hi roland12,

Keeping the air vents and cooling fins clean off debris, so the motor can dissipate it's heat.

Check that the machine it is driving, has no binding rotating matters which could slow the motor down, or make starting more difficult.
Do a load check when the machine is running and check that the current measured, is within the nameplate rating.
Check mains voltage too. Undervoltage to motors will reduce starting torque and may cause a motor to stall and burn out prematurely.
Check thermal overload settings set correctly.
Check fusing. Correct size, motorrated.

When fully isolated from the supply.

Check end play on bearings.
Do an insulation test on the windings.

Hope this will help

Kind regards, Raymond

The product of rotation, excitation and flux produces electricty.
Re: AC Motor Maintenance (3phase/1phase) [Re: RODALCO] #163222
05/04/07 07:25 AM
05/04/07 07:25 AM
WFO  Offline
Joined: Sep 2005
Posts: 202
Cat Spring, TX
On the 3 phase, make sure your voltages are balanced as well. A small imbalance in voltage will cause a large imbalance in current.

Re: AC Motor Maintenance (3phase/1phase) [Re: roland12] #163286
05/05/07 02:19 PM
05/05/07 02:19 PM
renosteinke  Offline
Cat Servant
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
There's not a lot to worry about ... as far as the motor itself is concerned. The right motor, installed correctly, will not only run darn near forever ... it will give lots of warning when it's getting tired.

There are three phase of maintenance:
1) Verify the selection;
2) Check the install; and,
3) Keep testing records

You verify the selection by comparing actual voltage and amp draw to the nameplate info. Check the running temps. As Rod said, keep it clean.

The motor has to be properly mounted, with the shaft/sheaves properly lined up. Belt/chain tension ought to be correct.

If you have a megger, there are a series of tests you can perform. These tests, for the most part, begin when the motor is new, and are periodically repeated. Comparing the results over time will give you ample warning that the motor is about to fail.

Re: AC Motor Maintenance (3phase/1phase) [Re: renosteinke] #163367
05/07/07 04:33 AM
05/07/07 04:33 AM
pauluk  Offline
Joined: Aug 2001
Posts: 7,520
Norfolk, England
From Alan Belson:

How long can a motor last? This is the original 400v 'Drouard' 5hp 3-phase 6 pole 900 rpm motor running my ancient bandsaw. Renovated a couple of years ago, this machine is in constant daily use. Built in Paris about 1931. I think you are supposed to re-grease the bearings on these old motors every 20,000 hours.

[Linked Image]

[Linked Image]


2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Fullerton, CA USA
Posts: 4,265
Joined: December 2000
Show All Member Profiles 
Top Posters(30 Days)
Admin 5
Trumpy 5
Popular Topics(Views)
244,875 Are you busy
181,993 Re: Forum
172,024 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.025s Queries: 15 (0.004s) Memory: 0.9692 MB (Peak: 1.1098 MB) Zlib enabled. Server Time: 2018-03-23 17:03:05 UTC