MCB Locks

[supasparxs]

Hi Guys,
as I've just started full time testing I've ssen a few strange things.

Today I was doing yet anothe EICR and found 3 SP MCB thjat were "Locked ON"

I was told by the maintenance sparks that

"so the tenants don't tamper with the metering the MCB's were locked on"

(there were CT's around the incomers and seperate;ly the locked on MCB's supply ing the meters)

I suspect that it is against the regs, but a reg to use against this fault.

any ideas guys?

Richard

 

[Geoffsd]

537.2.1.1

What about overcurrent protection?

 

[Strima]

Not really a fault, tampering with a protective device opens a whole can of worms.

 

[Knobhead]

The operating actuator can be locked in the on position as it doesn’t prevent the trip mechanism operating. The problem comes when the consumer / tenant wants to isolate the supply, it’s no different to the meter room being locked.

Look at any DNO MV switch, all switch positions are locked, it doesn’t prevent the unit operating under fault.

 

[supasparxs]

The operating actuator can be locked in the on position as it doesn’t prevent the trip mechanism operating. The problem comes when the consumer / tenant wants to isolate the supply, it’s no different to the meter room being locked.

Look at any DNO MV switch, all switch positions are locked, it doesn’t prevent the unit operating under fault.

ok, That makes sense,
however the DB is an Merlin Gerin Isobar 4.
and as this DB has MCB isolators the tenant could disconect the load and the isolate the circuit.

the whole thing about stop people tampering with the metering is a bit of a mute point as the tenant is a housing assiation, and not a corner shop on the verge of being make bankrupt.

Thanks again for your replies guys

Richard

 

[Geoffsd]

The operating actuator can be locked in the on position as it doesn’t prevent the trip mechanism operating.

Thanks for that. I wasn't sure - never thought about it.

The problem comes when the consumer / tenant wants to isolate the supply, it’s no different to the meter room being locked.

.

Not sure if you mean the meter room being locked is acceptable or not.

Noticed one yesterday (just a big cupboard) which has acquired a padlock.
I don't know who did it.