ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
What does your work place look like?
by HotLine1 - 11/23/20 03:35 PM
Where is Everyone?
by Lostazhell - 11/21/20 04:17 AM
Ground fault remover :-)
by dsk - 11/21/20 02:47 AM
Work Gloves?
by gfretwell - 11/20/20 10:17 PM
Reverse-feeding transformer in PV system?
by winnie - 11/19/20 06:49 AM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 17 guests, and 14 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
AC Motor Maintenance (3phase/1phase) #162354 04/18/07 02:44 AM
Joined: Apr 2007
Posts: 2
R
roland12 Offline OP
New Member
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 12:36 AM
Joined: Dec 2005
Posts: 860
R
RODALCO Offline
Member
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 06:25 AM
Joined: Sep 2005
Posts: 202
W
WFO Offline
Member
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 01:19 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Member
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 03:33 AM
Joined: Aug 2001
Posts: 7,520
P
pauluk Offline
Member
From Alan Belson:

Quote
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]


Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
JoeKP
JoeKP
Berkley, MA
Posts: 144
Joined: March 2008
Show All Member Profiles 
Top Posters(30 Days)
Trumpy 9
Popular Topics(Views)
271,887 Are you busy
205,750 Re: Forum
193,861 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3