Industrial Testing

[Tonkolili]

I work at an open cast mine, when an item of equipment is replaced , for example a 3 phase motor, do the maintenance electricians need to perform Earth Loop impedance tests etc, In my opinion they do because they have disturbed the integrity of the Earth to that circuit. My colleagues say it is unnecessary. Any comments please.

 

[telectrix]

i'd say no, because the motor is not part of the fixed wiring.

 

[Tonkolili]

yes but isn't it the same as replacing any item, say for instance if you replace a consumer unit, the regs say you must test every circuit as you have disturbed the integrity of the system

 

[pepparz]

yes u do, the test proves a good earth.

 

[Kamikaze]

I work at an open cast mine, when an item of equipment is replaced , for example a 3 phase motor, do the maintenance electricians need to perform Earth Loop impedance tests etc, In my opinion they do because they have disturbed the integrity of the Earth to that circuit. My colleagues say it is unnecessary. Any comments please.

How would you know if the motor was ever earthed to start with unless you did at least an earth loop test?

 

[telectrix]

problem there could be with control/start circuitry. a efli test uses 20A or so ( except if it's no-trip). i would rely on a R1+R2 or a R2 from start circuit to motor in addition to. to the efli reading for the fixed wiring.

 

[pepparz]

earth loop at starter then measure R2 from starter to motor and combine the 2

 

[telectrix]

think that's what i just said.:tounge_smile: