What is the science behind the 1 MOhm minimum insulation resistance? What is the basis for this particular value?
To give you the correct answer I need to find the old Megger insulation testing booklets I bought via Ebay some years ago.
First off there isn't a 1 Mohm minimum insulation resistance for an existing installation, when you are preparing an Electrical Installation Condition Report you need to make an engineering judgement as to whether the insulation resistance test result is acceptable; and it may be less than 1 Mohm.
Secondly, the insulation testing requirements are based on the standards laid down by insurance companies and the original requirement was based on a fraction of the total load the installation was to be loaded with.
I bet Bod knows the calculation without looking it up ?
What is the science behind the 1 MOhm minimum insulation resistance? What is the basis for this particular value?
To give you the correct answer I need to find the old Megger insulation testing booklets I bought via Ebay some years ago.
First off there isn't a 1 Mohm minimum insulation resistance for an existing installation, when you are preparing an Electrical Installation Condition Report you need to make an engineering judgement as to whether the insulation resistance test result is acceptable; and it may be less than 1 Mohm.
Secondly, the insulation testing requirements are based on the standards laid down by insurance companies and the original requirement was based on a fraction of the total load the installation was to be loaded with.
I bet Bod knows the calculation without looking it up ?
