RCBO

[Doctor Drivel]

These are combined MCBs (high current trips) and RCDS (earth leakage - imbalance trips)

If there is an imbalance between L & N or to earth will it trip even if the current rating has not been exceeded?

 

[Taylortwocities]

Yes!

Here's how it works
http://uk.answers.yahoo.com/question/index?qid=20060911064017AAH1akZ

 

[Doctor Drivel]

Yes!

Here's how it works
http://uk.answers.yahoo.com/question/index?qid=20060911064017AAH1akZ[/QUOTE]

It says:

"Combined RCD/circuit breaker units are available, and these combine the functions of an RCD with those of a conventional circuit breaker, responding appropriately to fault currents and overload conditions. These are known as RCBOs, and are available in 1, 2, 3 and 4 pole configurations. RCBOs will typically have separate circuits for detecting current imbalance (RCD function) and for detecting overload current (circuit breaker function); however the device for interrupting the flow of current will be common to both functions."

It says: "RCBOs will typically have separate circuits for detecting current imbalance (RCD function) and for detecting overload current (circuit breaker function);"

Still vague, however the two separate circuits may indicate that they are separate and operate individually.

 

[JohnD]

yes, the two parts do operate separately. You have an MCB, and an RCD, in the same plastic lump.

With MEM, the two parts are made separately, and clip together, so that (although common ones are carried as wholesalers' stock, and specials can be ordered from the factory) you can carry a few of the RCD "pods" in the common 30mA and less common 100mA sensitivities, and clip them onto any standard MEM MCB in your van or on your shelf (except the AD range). So if you want a C63/30mA you can assemble one; and if you want a B6/100mA you can assemble that.

The most common ones are C32/30mA in Industrial use, and B32/30mA for domestic rings though.

The MEM ones (very cleverly, i think) will fit into either the domestic Memera CUs or the industrial Memshield DBs, which, again, reduces the variations of stock you need to carry.

You may have guessed, I think they're great

edited: to clarify, as RF says below, even on the MEM, the RCD Pod just has a concealed trigger that operates the breaker in the MCB part; there aren't two sets of contacts, and there is only one toggle to put them on/off

 

[RF Lighting]

If there is an over-current fault on the circuit it will operate the overcurrent detection part of the device, which will trip the RCBO.

If there is an earth fault on the circuit it will operate the earth fault part of the device. This will also trip the RCBO.

Two seperate sensing circuits contained within one device, operating a single device to interupt the current flow.