- Reaction score
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On a PIR test to confirm Zs values i obviously go to thr BRB page 48.But when do i use the rule of thumb i.e 80% Method ?. I understand there are differences between a cold install to one that is in service as resistance changes when cables are warmer.
On previous posts i have noted to qualify for a extraneous part to be bonded a test can be made by using a insulation resistance tester set on 500v connecting one end to the MET and the other to the metal part in question.The reading shall not be greater than 0.022 meg ohms.On a large installation is the MET at the main intake or could it be at a sub board?Other posts and various books relate to a value of 0.05 OHMS to confirm if a bond is adequate does this relate to the main bond or supplementary and does MET mean main intake or sub board,I hope this makes sense
On previous posts i have noted to qualify for a extraneous part to be bonded a test can be made by using a insulation resistance tester set on 500v connecting one end to the MET and the other to the metal part in question.The reading shall not be greater than 0.022 meg ohms.On a large installation is the MET at the main intake or could it be at a sub board?Other posts and various books relate to a value of 0.05 OHMS to confirm if a bond is adequate does this relate to the main bond or supplementary and does MET mean main intake or sub board,I hope this makes sense