Question re: Portable Gensets & ELD safety switches - Page 2

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Re: Question re: Portable Gensets & ELD safety switches



Quoted text here. Click to load it

This is correct.

Quoted text here. Click to load it

Yes there is, however, it requires the genset output to be rewired and a good
quality earth (stake, etc) to be attached to the genset frame and the output
earth terminal.  If a gen is rewired for RCD use then the RCD must be fitted to
the generator, you cannot 'safely' use one on an extension cord.

The necessary rewiring entails connecting one side of the alternator to the
earth to form an earthed-neutral style circuit.  This point, and the other side
of the alternator, are then connected into the supply side of the RCD.

The Australian standard for generators and the wiring rules require the
generator to be wired this way if an RCD is used.   If an RCD is not used the
alternator must be left floating unless it is permanently wired into an
installation.  It is recommended that small (< 25Kw) portable gensets have the
output floating and not use an RCD, as follows (ref AS2790 cl 6.1.8 and 6.1.9).

6.1.8 Equipotential (earthing) facilities.The
following parts shall be in effective electrical contact
with each other:
(a) The engine frame.
(b) The generator frame.
(c) All external metal enclosing electrical equipment
or wiring.

6.1.9 Connections between main winding(s) and
frame. Connections between main winding(s) and the
frame shall be as follows:
(a) Single-phase winding (without earth-leakage
protection) . The winding shall not be connected
to the frame.
(b) Single-phase winding connected to a current-operated
(core balance) earth-leakage device
complying with AS 3190. The input neutral
terminal of the device shall be connected to the
earth terminal of the device (where that terminal
exists) or to a frame terminal (see Figure 1).

Commentary:
1. It is considered that, in the absence of
earth-leakage protection, a single-phase winding
is safer when isolated from frame. In the event
of a single fault to frame, the situation then
resembles an MEN installation (where one
conductor is earthed).

2. Where a core balance earth-leakage device is
fitted, the connection between winding and frame
is necessary to permit correct operation of the
device. If the device were subsequently removed,
it is likely (and recommended) that the
winding-to-frame connection would be removed.




Re: Question re: Portable Gensets & ELD safety switches



"David, not to be confused with the other Davids."
Quoted text here. Click to load it

David,

Many thanks for a most useful reply. This is what I was trying to find out.

Cheers,

Rod.......Out  Back



Re: Question re: Portable Gensets & ELD safety switches



Quoted text here. Click to load it


yes.


earth the neutral. (not that that's a good idea)

Quoted text here. Click to load it

probably.  as you have it in the case of an electrical connection between any
one of the output wires and the body of a user no current will flow
asif you were usuing an isolating transformer, and AFAIK they are as good as
ELDs except they don't trip in fault conditions.

Bye.
   Jasen

Site Timeline