What are the Most Common Causes of Electric Motor Failure?
Find how & why your fan, power tool, hoover, washing machine, etc, is making a horrible noise? Why it has stopped working. Simple Things you can Check without a test meter.
- For more information, see:
Fixing electric Motors: [ Ссылка ]
How to Buy a Bearing: [ Ссылка ]
If you need parts, try...
Carbon Brushes - (UK) - [ Ссылка ]
- (USA) - [ Ссылка ]
- (AUS) - [ Ссылка ]
Bearings - (UK) - [ Ссылка ]
- (USA) - [ Ссылка ]
- (AUS) - [ Ссылка ]
Bushes - (UK) - [ Ссылка ]
- (USA) - [ Ссылка ]
- (AUS) - [ Ссылка ]
Armature - (UK) - [ Ссылка ]
- (USA) - [ Ссылка ]
- (AUS) - [ Ссылка ]
Test Meter (Multimeter) - (UK) - [ Ссылка ]
- (USA) - [ Ссылка ]
- (AUS) - [ Ссылка ]
Disclosure: The links above are 'affiliate links' This means we may garner a small commission (at no cost to you) if you choose to make a purchase. Thanks for your support... 😃
How to Fix - if an electric motor starts making a horrible noise, or it just stops, what do you do?
The video describes straight forward electric motor fault finding & diagnosis without a test meter. What to look out for, when trying to identify an issue. Why it’s making a horrible noise, or why it’s not going very fast… Hopefully, it will help you decide if an item is repairable, or destined for the junkyard!
* Warning – Electricity can Kill *
- Make sure the power is disconnected before examining.
- Physically disconnect the device.
- If you have a testing device, check the item is dead (power is off) when opening any covers…
- Check and double check…
- If in doubt… Always consult a qualified electrician.
Does the Motor Smell?
If the motor smells horrible, it’s usually a bad sign. It’s often because the motor has got too hot. The windings (wire) in an electric motor are covered in a varnish, and insulation is often made of plastic and it may have started to melt. Burnt varnish & plastic stinks. The insulation may have broken down and shorts in the wiring may have occurred?
The noise can come from (in no particular order)…
Bearings (or bushes):
Dust & Debris:
Brushes:
The commutator:
Electrical noise:
Frequency:
Loose parts:
Alignment:
Carbon Brushes:
Carbon brushes pass electricity to the motor armature. Small springs are often used to push the carbon brushes against the motor armature to make electrical contact. Carbon is cheap. So, carbon brushes are designed to wear away, (rather than the expensive armature). No one explains that… As the brushes start to wear, they are pushed by the spring against the armature to ensure there is electrical contact. Don’t Leave it Too Late! If the carbon brushes are worn, they can cause excessive sparking on the armature. Please note: You can get the more expensive 'brushless' electric motors.
Brush Damage / Armature Damage?
The Brushes:
If the brushes wear away completely, the motor can end up running on the springs. The brush springs are a lot harder than carbon and and can wear the commutator. In most cases the springs can short out and blow the commutators, causing complete failure.
The Armature:
If the armatures blown, there’s not a lot you can do, other than fit a new armature.
It’s always important to replace the brushes before they completely wear out (and is a cheap solution).
If the Motor Doesn’t Smell & the Brushes are Fine, What can I do?
- The Wiring Should be Checked:
- Will the Motor Run if you Help it Spin? If yes, then it could be a defective starting capacitor.
- Thermal Protection. Some electric motors are fitted with a thermal trip to protect the motor.
- Has dust got inside?
0:00 Introduction
0:24 Describe basic electric motor fault finding.
1:16 Warning, make sure the power is disconnected before examining.
1:40 If the motor smells, it's usually a bad sign.
2:11 Smoke (heat) can be dangerous! Stop the motor! Unplug from the mains.
2:56 Does the motor make a horrible noise?
4:17 Have the carbon brushes worn out?
5:41 If worn, they can cause excessive sparking.
6:57 Replace the carbon brushes (a cheap solution).
8:24 If the Motor Doesn't Smell, what can I do?
