What should be the insulation between the body of the electrical water heater and the connecting cable as per ISI?

Question

Question

This question was previously asked in

ALP CBT 2 Electrician Previous Paper: Held on 22 Jan 2019 Shift 1

Answer 1

Before commissioning or installing a water heater, the insulation resistance should not be less than 1.00 MΩ as per ISI.

According to I.E. Rule 48:

The insulation resistance between the wiring of installation and earth should be of such a value that the leakage current may not exceed 1/5000 the part or 0.02 percent of the full load current.
The permissible voltage drop in a lighting circuit is 2% of the supply voltage plus one volt.
The maximum permissible voltage drop in a power industrial circuit should not be more than 5% of the declared supply voltage.
The insulation resistance of any wiring installation should not be less than 1MΩ.
The earth resistance should not exceed the value of one Ω.