ELCB on 3 phase

[Adamant]

Will a 4 pole ELCB work when connected to a 3 phase motor with no neutral if a neutral is connected to line side of ELCB ? no starting current worries to consider just wanting ELCB protection of hoist motor . Thanks

[chrisp]

The quick answer is: "Yes".

As long as all the actives (1, 2 or 3) and the neutral (if any) go through the one RCD coil, the RCD should function correctly. There is nothing stopping a 4-wire RCD being used in a 2-wire or 3-wire circuit - just leave the unused terminals disconnected.

[Adamant]

thanks for reply , i thought that was correct as it would pick up any inbalance between phases if there was leakage ?

[goq11k]

do you mean RCD or ELCB

i tried to respond last night but moderators stopped me i think

ELCB is for voltage rise on the earth circuit

RCD is for current rise on the earth circuit, (or lack of current flowing through the neutral circuit)

what are you trying to protect from, current leakaqge or voltage leakage? fuse for overload and thermal overload protection is normal on a motor

with a balanced load there is no current through the neutral, you'll find only the control circuit may have a neutral, i.e. 230v

the motor is balanced 400v.

[applied]

For those playing along at home rcd- residual current device, elcb- earth leakage circuit breaker (a combined circuit breaker and rcd)
Ebbd-a combination of letters I just made up.

[jago]

For those playing along at home rcd- residual current device, elcb- earth leakage circuit breaker (a combined circuit breaker and rcd)
Ebbd-a combination of letters I just made up.

I'm playing I'm playing ...so whats a RCBO?

[applied]

Wow not were realy getting down to nitty gritty but I suspect you are taking the PISS.
I refer to the elcb as combined as in a CB with an attached EL device specifically in this case for three phase as opposed to a rcbo a (rcd with overcurrent protection) you would find in a single phase circuit.

Very observant of you ten points.

[jago]

Only taking the piss in lower case some seriosness behind it .... heres some letters for you t h a n k s.:U