Question { 5523 }

How to use a insulation resistance tester on a three phase
electric motor?

Answer

Very simple. Measure ir between

r-y,y-b, b-r r-e,y-e,b-e

Question { Areva, 13106 }

Why temperature rise test is conducted in bus bars and
Isolators?

Answer

It is require to do this test for protection design system. i.e to find short circuit rating of busbar and base on this design protection system.

Question { Orchid, 11539 }

What is the difference between lubricating oil and insulating
Oil?

Answer

too much different
u measure short ckt test then u find more breaking capacity in insulation oil 40 kv/mm to 50 kv/mm

and other is viscosity is more in lubrication oil

Question { 19437 }

Which rccb 30ma,100ma,300ma sensitivity should be used in domestic line and what is difference, advantage and disadvantage of all three

Answer

Dear friends,
first it is common sense that in earthing you set more 100ma means when 100ma or more current is flow in nutral / earthing it may be trip. You aware that fatal current is 5 mA to 10 mA.
It is advisable to set 30 mA when in your home or industry you use 24 hours duty i.e continuous duty.
For higher capacity it i.e 100mA or more is apply where more current rated single apparatus is use. It is advisable to fit rccb with refrigerator, single phase water sump motor or pump and heater use in your house. In those house where small kids advisable to fit rccb.