Testing of MCB/RCD/RCCB/RCBOs

[chrisdicko]

Is it a legal requirement to test MCB/RCD/RCCB/RCBOs etc in Industry??

Just I work in a factory, and since I've been here not one has been tested for correct functionallity.

If it is a legal requirement, under which legislation does it come under?


Cheers

 

[Spark123]

In the electricity at work regulations, regulation 4 (2) states "As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger."
An RCD (RCCB, RCBO etc), should be tested in line with the manufacturers instructions, a failure to do this may be looked upon as a failure to comply with Regulation 4 (2).
BS7671 recommends the test button of an RCD is pressed quarterly to ensure it disconnects the supply and a label stating to this effect be placed.
The state of the factory's electrical installation should also be inspected, tested and its condition recorded (Periodic Inspection Report) at a pre determined interval unless there is an ongoing maintenance regime in force.

 

[nozspark]

RCB's and RCBO's should be tested as stated above,

but how would you test a MCB?? remember that a B32A should trip within 5 seconds at 5 x its rated current - so to test it you will have to put an overcurrent fault of 160A on it and then have an accurate timer to time it!! Also any test of an MCB, or a RCD for that matter, will only show that it worked when you tested it, not that it will work in the future!!

Can you imagine the overload current that you would have to use to test a D63A MCB (945A), and also how expensive that piece of test equipment would be!!

 

[Spark123]

Agree, tho I thought the magnetic setting needs to disconnect in 0.1s? The only things you can really do with them is turn them off and ensure they disconnect the phase conductor as part of the PIR, give them a visual and check the screws are tight, check suitability, identification etc.

 

[DESL]

Agree, tho I thought the magnetic setting needs to disconnect in 0.1s? The only things you can really do with them is turn them off and ensure they disconnect the phase conductor as part of the PIR, give them a visual and check the screws are tight, check suitability, identification etc.

And of course measure Zs

As far as testing the functioning of MCB is concerned - would you test a fuse!!

We have to rely on CPDs functioning to the BS they manufactured to.