Unusual MCB

Hi all.


I received and opened the Federal Electric RCBO I got for a tenner from ebay and have found the same thing. No instantaneous trip

mechanism.

Hard to believe on an RCBO.

This one is actually a 10mA.

It's the MCB not marked with types that are like this but all the RCBOs I saw on ebay had no type marking.

It's not that easy to tell from the picture as I had to remove it but there is a centre part so the thermal mechanism would be

positioned above the electronics, but separated. You can see the fixed part of the contact near the coil.

The electronics are permanantly fed so it warms up even when switched off and if the RCBO is plugged in first the neutral tail

becomes live. The trip coil is directly fed by the yellow wire on one side from the L on the load side, so at least if it trips it

will cut the power to the trip coil. The test button is a link to neutral but there is no switching on that so keeping it pressed in

after tripping will overhead the test resister. However, I tried this and nothing overloaded; don't know why. Maybe I didn't hold

it long enough but in theory the length of time I did hold it I expected some noise and wisps of smoke.

On this one the test button is transparent red and there is an trip LED on the board. Some have non-transparent yellow buttons so

they probably don't have this LED.

This is a 30A breaker and the L and N conductors seem a bit small.

The large neutral tail is misleading as it is connected through a soldered crimp to 2 white conductors for load current and neutral

link to the circuit board.

It seems a bit strange that what seems and old bakerlite device with no instantaneous trip mechanism has more modern LED and 2 IC packages on the circuit board.

Hi all.


I received and opened the Federal Electric RCBO I got for a tenner from ebay and have found the same thing. No instantaneous trip

mechanism.

Hard to believe on an RCBO.

This one is actually a 10mA.

It's the MCB not marked with types that are like this but all the RCBOs I saw on ebay had no type marking.

It's not that easy to tell from the picture as I had to remove it but there is a centre part so the thermal mechanism would be

positioned above the electronics, but separated. You can see the fixed part of the contact near the coil.

The electronics are permanantly fed so it warms up even when switched off and if the RCBO is plugged in first the neutral tail

becomes live. The trip coil is directly fed by the yellow wire on one side from the L on the load side, so at least if it trips it

will cut the power to the trip coil. The test button is a link to neutral but there is no switching on that so keeping it pressed in

after tripping will overhead the test resister. However, I tried this and nothing overloaded; don't know why. Maybe I didn't hold

it long enough but in theory the length of time I did hold it I expected some noise and wisps of smoke.

On this one the test button is transparent red and there is an trip LED on the board. Some have non-transparent yellow buttons so

they probably don't have this LED.

This is a 30A breaker and the L and N conductors seem a bit small.

The large neutral tail is misleading as it is connected through a soldered crimp to 2 white conductors for load current and neutral

link to the circuit board.

It seems a bit strange that what seems and old bakerlite device with no instantaneous trip mechanism has more modern LED and 2 IC packages on the circuit board.