Capacitors for electric motors

Capacitors for electric motors, how to identify and two ways to test them.

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[timallen]

Perfect, ‘ we can do’, testing, understanding the testing and SAFETY . Top teaching empowerment thank you JW

[Dime_Bar]

How about a follow up video on how capacitors work on motors.

[combie]

Well what would you Just watched this on the 1st and my tumble dryer packed in yesterday and the cause after some simple testing... the capacitor for the motor :) Thank's John - new one ordered and to be fitted tomorrow :)

For those interested:
White Knight CL 447WV
Symptoms - No grinding noises/bearings smooth/drum not locked up/belt intact/timer/heating element all work fine and motor powers up but no spinning drum. If you give the drum a little push start it works as normally, when drum stops to change direction it wont spin again without a nudge.
Fix - Replace motor capacitor

[Robonthemoor]

I’ve just found JW the best on YouTube fantastic delivery keep em coming I can’t get enough 👍

[bobrose]

Well done John, useful information and great presentation. I have the benefit of a private water supply and multi stage single phase borehole pump some 88m below ground. I forget the startup capacitor value but they are like bake bean cans (excuse the phrase!} and when they periodically blow they usually explode leaving a large hole in the side of the case! 37A startup current would account for this. An explanation of the circuit would be useful and the considerable advantages of 3 phase motors - now available by using an inverter in this scenario.

[metaxa]

John it is always a pleasure to watch your videos! cheers!

[TheEulerID]

Something else that is very important is that it's an AC rated capacitor and not a DC electrolytic as the latter will fail catastrophically using AC. Of course they are unlikely to be confused as a DC 450v electrolytic of that capacity will be much smaller and look rather different, but just in case...

[squaidinkarts]

Thank you! You're great at explaining

[Smudgie]

Are there any precautions to take when re-connecting a capacitor?

[andreim]

Had one give up the ghost last week in a central heating boiler pump. There was no leaking or deformation in the cap, but that's not unusual in this type of poly caps. One thing worth mentioning is the fact that if the cap is blown, in some cases the motor will draw more amps and fry itself.

[ianmaynard]

My sun bed has a missing 240v 50 uf capicitor missing. Ive bought another but the wires coming out of it are both white yet my sunbed has a brown and blue wire to attach to it.
My question is how do i know which wires go where? Thanks in advance

[marhar]

Excellent video! @11:17 could you explain this further and provide a demonstration?

[williammcgrattan]

JW always makes it easy to understand, 👍. Brilliant

[tim]

Good one John now I can test my capacitor s on my compressor she’s not starting

[chrismallatratt]

Another fantastic informative video. Thanks J.W.

[davidfildes]

With an old analog meter can test if open or shorted. Using continuity (resistance) apply to terminals then reverse a good capacitor will kick the needle....Good idea to short capacitor before removing from motor.

[maldridge]

does the list of uses also include house gate motor capacitor? Are those also considered single phase electrical motors?

[omarhadjarab]

Using this Fluke(same as mine) and a Robin won't be enough to determine the health of a capacitor even if you get the correct capacity (Farads) when measured.
What you need in reality is an ESR meter to meausure the Effective Series Resistance, if it within the proper value the cap would be good and the machine would work efficiently, or else, many bad scenarios could take place, fire, damage to motor, fried PCB, or even electric shock in some instances.

[DrGreenGiant]

Safety point about supercapacitors; if you short it to remove the voltage then leave it for a while, it may restore its charge. Leave them shorted!

[adrianTNT]

To make a 220V motor spin slower, do I need a smaller capacitor than original, or a larger one ? And does it directly multiply ? E.g a half or a double size capacitor would give half or double the motor speed ?