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Fake circuit breakers

broadgage
Seem to be on the increase.

Makes me wonder if we should be testing samples before installation ?

A full and proper test requires relatively elaborate lab facilities, but perhaps a crude test involving say a vehicle battery and a 100 amp fuse.

This wont reveal all faults, but would at least weed out the most blatant "no trip" types.

An MCB tested thus might of course have been damaged, so perhaps test the odd sample and only install untested examples from the same batch. Rather expensive though.
youtube. fake MCB dismantled
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  • 0
    broadgage:

    I doubt that a car battery could deliver  6KA. The maximum cranking amps are often in the region of 200 amps to 300 amps, at which current the voltage drops by at least 10%, that in turn suggests a maximum short circuit current of very roughly 2KA to 3KA.


    12 volts DC can not maintain an arc, the minimum is about 18 volts.


    So testing with a car battery is rather basic, but would weed out the worst examples


    Wouldn't it be easier to set up a 240 Volt test rig with too many electric fires plugged in, to test a miniature circuit breaker. That might be easy for a B6 or B16 M.C.B. For a B32 or B40 a dedicated rig with many well ventilated resistance elements would be good. An Ammeter could be installed in circuit, or a clamp meter to read the actual current flowing. Then normal A.C. can be applied. The rig could have temporary shrouded spring loaded hinged contacts for the M.C.B. terminals so that multiple testing could be done. 


    Z.


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  • 0
    broadgage:

    I doubt that a car battery could deliver  6KA. The maximum cranking amps are often in the region of 200 amps to 300 amps, at which current the voltage drops by at least 10%, that in turn suggests a maximum short circuit current of very roughly 2KA to 3KA.


    12 volts DC can not maintain an arc, the minimum is about 18 volts.


    So testing with a car battery is rather basic, but would weed out the worst examples


    Wouldn't it be easier to set up a 240 Volt test rig with too many electric fires plugged in, to test a miniature circuit breaker. That might be easy for a B6 or B16 M.C.B. For a B32 or B40 a dedicated rig with many well ventilated resistance elements would be good. An Ammeter could be installed in circuit, or a clamp meter to read the actual current flowing. Then normal A.C. can be applied. The rig could have temporary shrouded spring loaded hinged contacts for the M.C.B. terminals so that multiple testing could be done. 


    Z.


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