Re: [CAD_CAM_EDM_DRO] Re: ELCB Issues

xj5373 wrote:

> Thanks for this Lester,
> I popped in to the workshop this morning to have a look and started
> by powering the machine up with the charge pump relay removed removed
> from its base. This relay is powered up by the breakout board and
> switches 240 v onto the stepper power supply and the inverter.
> Machine started up fine and I was able to test the coolant pump which
> is switched diectly from the break out board. I powered down again,
> re-fitted the relay and powered it back up and everything started
> normally. Based on this I completed the job I had on the machine then
> switched it off for lunch.
>
> I wondered if there might be some sort of transient generated around
> the relay area or even in the stepper power supply that might be
> causing this problem? Is there some sort of suppression I should have
> fitted anywhere in this area? I am scratching a bit here being
> essentially a mechanical engineer but I am thinking in terms of back
> EMFs and so on around coils??? Another thought was whether I should
> put in an additional manual switch between the charge pump relay and
> the stepper power supply and even the inverter.

Same question as last time - what is actually connected to earth?

The ELCB is looking for a difference in current that flows between the live
and neutral. That difference would normally be flowing into the earth when it
should not be. If the DC side of the breakout board is connected to earth,
then the live and neutral should only be connecting to a transformer, or the
other side of a relay. If the relay is 'leaky' ( not providing proper
isolation), then the ELCB is correctly working, and the relay needs replacing
with one that can handle 240V between coil and contacts.

--
Lester Caine - G8HFL
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