Electric Motor Question
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steveindenmark
Legendary Member
Pedelecs uk is a great forum for this type of question.
subaqua
What’s the point
- Location
- Leytonstone
[QUOTE 3887676, member: 9609"]Macerator motor is just making a humming noise and won't start, but If I flick the blade to get it turning it starts up and runs properly - is this a sure sign it is the capacitor ?
@subaqua[/QUOTE]
yes , if it is a single phase induction motor.
if it is a universal AC/DC then capacitor is for power factor correction.
however , yes there is always a however, on the universal if one of the windings is breaking down ( open circuit) then it wont start till you give it a flick
@subaqua[/QUOTE]
yes , if it is a single phase induction motor.
if it is a universal AC/DC then capacitor is for power factor correction.
however , yes there is always a however, on the universal if one of the windings is breaking down ( open circuit) then it wont start till you give it a flick
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
[QUOTE 3887719, member: 9609"]can anyone explain what the numbers are on the side of the capacitor the one that I think has failed says
uf 14 +-5%
500v 25/085/21
450v 25/085/21
400v 25/085/21
I have a found a spare one (from what i don't know)
its rating is
25uf 50/60hz
450v ac 25/70/21
would that be close enough or might it all go bang ?[/QUOTE]
The first line says Micro Farads - 14 of them with a 5% tolerance - 14uF+/-5%
Then you have voltages but why 3 and the other numbers I don't know. Worth a Google....
uf 14 +-5%
500v 25/085/21
450v 25/085/21
400v 25/085/21
I have a found a spare one (from what i don't know)
its rating is
25uf 50/60hz
450v ac 25/70/21
would that be close enough or might it all go bang ?[/QUOTE]
The first line says Micro Farads - 14 of them with a 5% tolerance - 14uF+/-5%
Then you have voltages but why 3 and the other numbers I don't know. Worth a Google....
subaqua
What’s the point
- Location
- Leytonstone
[QUOTE 3887719, member: 9609"]can anyone explain what the numbers are on the side of the capacitor the one that I think has failed says
uf 14 +-5%
500v 25/085/21
450v 25/085/21
400v 25/085/21
I have a found a spare one (from what i don't know)
its rating is
25uf 50/60hz
450v ac 25/70/21
would that be close enough or might it all go bang ?[/QUOTE]
also depends if it is capacitor start or capacitor run. it isn't going to go bang. what will happen if the capacitor is not the correct size is slow damage from
a) resonance if too small
b) winding burning out if too big
uf 14 +-5%
500v 25/085/21
450v 25/085/21
400v 25/085/21
I have a found a spare one (from what i don't know)
its rating is
25uf 50/60hz
450v ac 25/70/21
would that be close enough or might it all go bang ?[/QUOTE]
also depends if it is capacitor start or capacitor run. it isn't going to go bang. what will happen if the capacitor is not the correct size is slow damage from
a) resonance if too small
b) winding burning out if too big
Last edited:
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
25 = minimum working temperature
085 = maximum working temperature
21 = duration (days) of the humidity test.
The Voltages refer to hours of operating life
085 = maximum working temperature
21 = duration (days) of the humidity test.
The Voltages refer to hours of operating life
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
500V = 3000 hours
450V = 10000 hours
400V = 30000 hours
450V = 10000 hours
400V = 30000 hours
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
It's a slow morning at 26 mansionsAre you wearing your anorak?
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
[QUOTE 3887823, member: 9609"]So the capacitor that has failed is 14uF and the spare that I have is 25uF
I connected it up to the 25uf and the motor perfectly, does this prove that it is the capacitor that has failed ? and presumably since it is about double the recommended if I left it connected it is likely to burn the motor out prematurely ?
And am I right in thinking it is a start capacitor ?[/QUOTE]
Yes - your original capacitor was faulty.
Now source the correct spec.
Just type all those numbers into google......
I connected it up to the 25uf and the motor perfectly, does this prove that it is the capacitor that has failed ? and presumably since it is about double the recommended if I left it connected it is likely to burn the motor out prematurely ?
And am I right in thinking it is a start capacitor ?[/QUOTE]
Yes - your original capacitor was faulty.
Now source the correct spec.
Just type all those numbers into google......
Cheddar George
oober member
- Location
- Location: Location
[QUOTE 3887823, member: 9609"]So the capacitor that has failed is 14uF and the spare that I have is 25uF
I connected it up to the 25uf and the motor perfectly, does this prove that it is the capacitor that has failed ? and presumably since it is about double the recommended if I left it connected it is likely to burn the motor out prematurely ?
And am I right in thinking it is a start capacitor ?[/QUOTE]
Disconnect it and source the correct capacitor, the 25uF will have a large effect on the running current of the motor.
The voltages listed on the original indicate it is a "run" capacitor, this the type you need to buy (start caps are usually rated approx. 250v).
I connected it up to the 25uf and the motor perfectly, does this prove that it is the capacitor that has failed ? and presumably since it is about double the recommended if I left it connected it is likely to burn the motor out prematurely ?
And am I right in thinking it is a start capacitor ?[/QUOTE]
Disconnect it and source the correct capacitor, the 25uF will have a large effect on the running current of the motor.
The voltages listed on the original indicate it is a "run" capacitor, this the type you need to buy (start caps are usually rated approx. 250v).
twentysix by twentyfive
Clinging on tightly
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- Over the Hill
Ah - the D is 1000hrs operating life at 500V
You don't really need to worry about all that - just find another capacitor with those specs and it'll be fine. There will be a surge voltage (more that 240) on start up probably which the capacitor might shunt.
Yes those temps are odd. If you dig deep enough you may be able to unearth the tech specs for the tests and make your own judgement.
Water tight is not the same as gas tight tho'. Much harder to make things gas tight.
You don't really need to worry about all that - just find another capacitor with those specs and it'll be fine. There will be a surge voltage (more that 240) on start up probably which the capacitor might shunt.
Yes those temps are odd. If you dig deep enough you may be able to unearth the tech specs for the tests and make your own judgement.
Water tight is not the same as gas tight tho'. Much harder to make things gas tight.
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
[QUOTE 3887891, member: 9609"]Just ordered a new one of the the same spec £6.50 inc postage - which is a little less eyewatering than £200 for a new macerator.
the new capacitors manafacturer is "Ducati" should have a nice note to it lol[/QUOTE]
Done and dusted @User9609
I love these fixes as it's the Internet at it's best and the cost is always minimal
the new capacitors manafacturer is "Ducati" should have a nice note to it lol[/QUOTE]
Done and dusted @User9609
I love these fixes as it's the Internet at it's best and the cost is always minimal
classic33
Leg End Member
All you've got to do now is swap the two, when the new one arrives.
