Re: ELCB Issues

Thanks for the replies and I understand what I need to look for. Just
before I launch into this though is there a quick fix to feed the
machine from the non ELCB side of the consumer unit or is this a no
no?
Ian

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Kevin Martin" <kpmartin@...>
wrote:

>
> Just to clarify what could be ambiguous wording, The ELCB is

looking for

> a difference between current that flows on the live conductor and

the

> current that flows on the neutral conductor.
> If some part of the circuit has a connection between neutral and

earth,

> it will not normally conduct appreciable current because neutral and
> earth are theoretically at the same potential and the ELCB might not
> notice. If, as the relay contacts open, the neutral contact opens
> slightly faster, *all* the current will now flow through the

alternate

> path to earth until the live-conductor contact also opens and any

arcing

> is quenched, up to 1/120th (1/100th at 50Hz) of a second. The ELCB

is

> made to trip on only a tiny difference between the live- and
> neutral-conductor current (only a few milliamps), and here you are
> giving it an imbalance of several amps for a few milliseconds,

probably

> enough to trib the breaker.
> As Lester (and perhaps others) suggested, the cure is to ensure

there is

> no path between the neutral supply line and earth. It does not
> necessarily have to be a low-resistance DC path, even a few k-ohms

(or

> the equivalent capacitance at that frequency, a few microfarads)

would

> do it.
> -Kevin Martin
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Lester Caine
> [...]The ELCB is looking for a difference in current that flows

between

> the live and neutral.[...]
>