Capacitors
- Thread starter JdoubleU
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hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Some times when large contactors have a large inrush on the coil, they do this instead of up sizing the 24 volt transformer.
What is the reason they do this?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
the same reason they use capacitors on motors to over come voltage drop, a capacitor can give a boost to a load when it has a large inrush current, transformers, contactor coils and motors are common for this, if the AC compressor contactor coil has a fairly large inrush current it would or could overload the 24 volt supply transformer, the capacitor helps by giving an extra boost when the inrush current hits the transformer.
this is kind of the same thing when they use a boost capacitor to help start a motor/compressor when there is a voltage drop issue.
Not so fast guys..
First off, what size, type, and rating is this capacitor? A standard electrolytic cap connected to AC will simply explode. A mylar or other type of non-polarized cap might be there for boosting inrush capability, but doesn't sound right for such an application.
If the device (maybe it's not a cap) looks like a disc it may be a MOV for surge prevention.
A picture would be helpful here as well as make/model of A/C unit.
First off, what size, type, and rating is this capacitor? A standard electrolytic cap connected to AC will simply explode. A mylar or other type of non-polarized cap might be there for boosting inrush capability, but doesn't sound right for such an application.
If the device (maybe it's not a cap) looks like a disc it may be a MOV for surge prevention.
A picture would be helpful here as well as make/model of A/C unit.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
And your ears will ring for some considerable time afterwards. And it will take all that time top vacuum up the bits.
Exploding electrolytics are simply horrible.
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