Re: ELCB Issues

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.

Ian

Ian
--- In CAD_CAM_EDM_DRO@yahoogroups.com, Lester Caine <lsces@...>
wrote:

>
> xj5373 wrote:
> > Hi,
> > I have stripped out the old control system from a Denford

Easimill and

> > replaced with Mach3 via a Bob Campbell break out board. It works
> > beautifully but from the start I had a problem with the machine
> > dropping out the ELCB on the mains supply. The machine is plugged

into

> > a ring main which is fed via an earth leakage circuit breaker

from our

> > consumer unit (I should say that I am in the UK). I found that if

I

> > Estopped Mach3, this drops a relay connected to the change pump

which

> > takes the power off the stepper power supply. Giving it a minute

or two

> > allowed me to isolate the machine from the mains without the ELCB
> > dropping.....more often than not. Isolating immedaitely after

Estop

> > seemed more likely to drop the ELCB. I have opeated this way

since last

> > summer but just now I can't reset without losing the ELCB. I have

the

> > machine powered up but in Estop mode, pressing reset powers the

relay

> > via the charge pump output of the break out board which switches

240V

> > onto the stepper power supply and the inverter which is

controling

> > spindle speed.
> > I know what the ELCB does but what is it that is tripping it? Any

help

> > or hints greatly appreciated.
>
> The only thing that will trip the ELCB is an earth fault. So there

must be

> something giving feedback into the protective earth. The first

thing I would

> be looking at is what is connected to that earth. I don't like the

mains

> arrangements on any of the American boards I've seen and none of

them pass the

> European creepage and clearance rules. Which need to be need to be

a good 2

> times that needed for 110V ;) So I tend to stick to external mains

components

> such as solid state relays and just run DC from the boards. Then

you can

> ensure clean live and neutral connections.
>
> --
> Lester Caine - G8HFL
> -----------------------------
> Contact - http://home.lsces.co.uk/lsces/wiki/?page=contact
> L.S.Caine Electronic Services - http://home.lsces.co.uk
> MEDW - http://home.lsces.co.uk/ModelEngineersDigitalWorkshop/
> Treasurer - Firebird Foundation Inc. -

http://www.firebirdsql.org/index.php

>