Safely discharging a capacitor
powerstation wrote:
"Dave D" wrote in message
...
"paulfoel" wrote in message
oups.com...
Going to attempt to change the capacitor on my tumble dryer... Its a 8
micro-Farad one.
I think its dead anyway but I'm assuming I can check with a multimeter?
What sort of voltage/current is one of these likely to have?
Assuming it is still ' live' how do I discharge it to make it safe?
Does the motor have brushes and a commutator? If so, change the brushes
before you start looking elsewhere, they're seldom expensive and are a
consumable item. Capacitors may or may not last the life of an appliance
but brushes are certain to wear from day one and are usually the first
suspect in a misfiring/intermittant motor.
With brush type motors, the brushes wear down and consequently less
pressure is applied by the spring, causing a higher resistance/poorer
connection between brush and commutator. An arc is caused, which heats the
brush and can deform the casing causing the brush to stick, making the
problem increase exponentially. It also causes the commutator to become
blackened which makes matters even worse.
I'd take out the brush carriers and check the brushes move freely and that
there's plenty of length left on them. Also check the commutator is clean.
If the motor does not have a brush/commutator arrangement, I'd check all
connections are secure and check the control board for dry/cracked solder
joints before suspecting component failure.
Dave
nonsense it is clearly an induction motor.
Yep. It is.
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