3phase breaker made of 3 single phase breakers

Tim · Jan 17, 2014

Hi guys,

Is there a difference between 3 single phase breakers next to each other (with a linking bar) and 1 3 phase breaker?

Does the 3 phase breaker have anything special in it or is it just 3 single phase breakers stuck together with a bar in the switches?

Cheers,
Tim

Darkwood · Jan 17, 2014

On the side is a linking pin to the mechanical system of the ajoining breaker .... if it trips it then trips its adjoining mcb, its like a mousetrap - just needs a slight pressure to activate the trip.

The linking bar on the top where you operate them couldn't physically open the other breakers as it requires too much force ... the mcbs will all trip whether or not this switch bar was on or not.

Guest55 · Jan 17, 2014

Come on , fess up

what your really asking is can you retro bodge 3 single modules that you already have , into 1 3pole device cos the wholesalers are trying to spank you over the cost of a proper unit.

i can smell a scam a mile away lol.

Tim · Jan 17, 2014

darkwood said:
On the side is a linking pin to the mechanical system of the ajoining breaker .... if it trips it then trips its adjoining mcb, its like a mousetrap - just needs a slight pressure to activate the trip.

The linking bar on the top where you operate them couldn't physically open the other breakers as it requires too much force ... the mcbs will all trip whether or not this switch bar was on or not.

Cheers for the quick reply.

I wasnt sure if the linking pin had another function. I was just going to pull one apart but i thought id ask here first.

Cheers,
Tim

Tim · Jan 17, 2014

biff55 said:
Come on , fess up

what your really asking is can you retro bodge 3 single modules that you already have , into 1 3pole device cos the wholesalers are trying to spank you over the cost of a proper unit.

i can smell a scam a mile away lol.

Lol, it would make life easier if you could do that every time

guest119 · Jan 17, 2014

And you could use 3 different amperage off breakers too.
One for a shower, one for a fan and one for a shaver unit.

Only playing, reference a recent thread.

Boydy

Marvo · Jan 17, 2014

I agree with Biff, sounds like you're taking a chance but that's not a bad thing

. In this case it's not a good idea though, as Darkwood says it's not just the lever on the triple pole breaker that's physically joined, it's the internal tripping mechanisms as well so your idea won't work I'm afraid.

alanl · Jan 18, 2014

I had a similar thing on an EICR last year.
3 phase, the link between the breakers was broken, so 2 phases would go off, then you would have to flip off the other one separately.
I wasnt quite sure if I should give this a code.
I asked on the IET forum. The replies were "make an observation, not potentially dangerous".
Think of fuses supplying 3 phases - 3 separate fuses to take out, just like 3 separate CB's.

It isnt good practice to put a new install in with 3 separate CB's, but I cannot see it breaking any Regs.

GMES · Jan 18, 2014

Boydy said:
And you could use 3 different amperage off breakers too.
One for a shower, one for a fan and one for a shaver unit.

Only playing, reference a recent thread.

Boydy

You little tinker, can't believe MDJ ended up getting banned but the thread did get a bit heated

guest119 · Jan 18, 2014

alanl said:
I had a similar thing on an EICR last year.
3 phase, the link between the breakers was broken, so 2 phases would go off, then you would have to flip off the other one separately.
I wasnt quite sure if I should give this a code.
I asked on the IET forum. The replies were "make an observation, not potentially dangerous".
Think of fuses supplying 3 phases - 3 separate fuses to take out, just like 3 separate CB's.

It isnt good practice to put a new install in with 3 separate CB's, but I cannot see it breaking any Regs.

But it no longer does what the designer of the installation intended.

Boydy

guest119 · Jan 18, 2014

GMES said:
You little tinker, can't believe MDJ ended up getting banned but the thread did get a bit heated

Like big Arnie, he'll be bachk.

Boydy

Hawkmoon · Jan 18, 2014

alanl said:
I had a similar thing on an EICR last year.
3 phase, the link between the breakers was broken, so 2 phases would go off, then you would have to flip off the other one separately.
I wasnt quite sure if I should give this a code.
I asked on the IET forum. The replies were "make an observation, not potentially dangerous".
Think of fuses supplying 3 phases - 3 separate fuses to take out, just like 3 separate CB's.

It isnt good practice to put a new install in with 3 separate CB's, but I cannot see it breaking any Regs.

Make an observation? - If the 3 separate mcbs are feeding a 3 phase motor and one trips (for whatever reason) then the motor may continue running on the remaining phases ('single phasing') - this can/will cause damage if left unnoticed.

Flanders · Jan 18, 2014

Hawkmoon said:
Make an observation? - If the 3 separate mcbs are feeding a 3 phase motor and one trips (for whatever reason) then the motor may continue running on the remaining phases ('single phasing') - this can/will cause damage if left unnoticed.

But what if the motor was protected by 3 separate BS 88 fuses as most are would you code 3 That ?