3 pole mcb tracer help.

Andrew Hutton · Jul 23, 2017

Question I am trying to trace a triple pole mcb. The panel that the supply goes to has only a 3ph supply no neutral. The building is a NHS site and has many distribution boards some marked up correctly. The problem is I can't go round knocking of breakers due to equipment etc. Was looking at a mcb tracer but they seem to require a neutral to operate the transmitter.
Does any one have a idea of how to trace the mcb or recommend a mcb/cable tracer. Circuit is live.
Thanks Andrew

westward10 · Jul 23, 2017

Have you tried using a clamp meter.

Andrew Hutton · Jul 23, 2017

Yes tried that couldn't fully pinpoint the circuit.

telectrix · Jul 23, 2017

if the phases are not balanced, by clamping each phase at a time, you should get unique readings

westward10 · Jul 23, 2017

I don't suppose the panel has an internal socket or perhaps you could fit a temporary socket and plug in a fan heater.

b-spark · Jul 23, 2017

Martindale version, just earth it. I think they actual have a lead in the kit. I will say its never 100% depends on the wiring method swa should be fine, trunking not so much.

The Ghost · Jul 23, 2017

maybe going to a motor then? for a lift? Look for equipment that has no neutral?

davesparks · Jul 23, 2017

Vortigern said:
maybe going to a motor then? for a lift? Look for equipment that has no neutral?

I think he's working the other way around, he's got trying to find the mcb which feeds the panel rather than what a particular mcb does.

davesparks · Jul 23, 2017

westward10 said:
I don't suppose the panel has an internal socket or perhaps you could fit a temporary socket and plug in a fan heater.

But there's no neutral at the panel

PEG · Jul 24, 2017

If you do not know what it feeds,it could be vital or nothing...not being able to isolate it,hampers things.

Some extra curricular research,may throw up a clue...even tracking down a previous engineer,whoever the contractors were.

Being able to isolate all/most of the other known circuits,can help,as can a data logger on the circuit in question,which could assist in identifying via load/use characteristics.

If it matters enough to someone,you will get the freedom to make the choices needed,to enable identification both safely,and without disruption.