Question { Bhel, 188761 }

what is the difference in MCB, MCCB, RCCB, ELCB, & MPCB
(motor protection circuit bracker)

Answer

Prajapati's answer is good.

ELCB is actually voltage operated and need a stable
connection to earth electrode.

RCCB is actually seeing the difference in the current
flowing in and out of the circuit. If there is a leakage,
the sensing circuit will detect the leakage and trigger the
RCCB to trip.

Question { 18914 }

why battery room in substation is black coloured?

Answer

There is no requirement of coloured for bateries in
substation

Question { 13629 }

what is the resistance value of our human body?

Answer

human body resistance is depend on how the current go
through out human body and the age. Normally, for safety
calculation, It 's 200K Ohm

Question { 13167 }

what is the max working temperature of an oil filled
transformer say of about 1500kva.

Answer

According to ABB,
The temperature rise limits for transformers with
temperature class of insulation A is then:
- Maximum winding temperature rise of 65ºC
- Maximum top oil temperature rise of 60ºC
If the transformer is designed for service, where the
temperature of cooling air exceeds one of the
maximum values, the allowable temperature rise for the
winding, core and oil shall be reduced