insulation testing at spurs with neons,fans with transformers and showers with shower pull sw

[r.b]

I know that you have to switch a spur with a neon or switch the spur off going to a fan transformer.Plus turn the pull switch off at a shower with a neon otherwise I will get a wrong reading.But at the same time surely when i come to do line to earth test on mega on the same scenarios the earth would not interfere with anything would it?Its only going to an earth point this correct I just need to clear it up thanks.

 

[r.b]

Can I do an insulation test test all the way through to a shower outlet point or would this damage the shower?Am I best off just testing it to the pull switch point and turning it off there before I do the test?

 

[Doc Hudson]

Threads merged r.b. as they are basically the same question, or will certainly have some overlapping replies. Assuming all polarity is correct, testing with the two lives combined to earth (Line+Neutral - Earth) should not cause any damage to any connected equipment and should have no errors due to neon indicators. Still best to test at 250v first though to indicate any potential problems.

Doc H.

 

[Technician]

Had just this query once. I answered that reducing the test

voltage should not be a habit and only done with a good

justification.

 

[Zeespark]

Tech, the reduction in test voltage is for possible fault finding before using the 500V on testing at 230V, not as a get out clause so to speak.

AndyGuinness

 

[Doc Hudson]

Had just this query once. I answered that reducing the testvoltage should not be a habit and only done with a good

justification.

Tech, the reduction in test voltage is for possible fault finding before using the 500V on testing at 230V, not as a get out clause so to speak.AndyGuinness

As Zeespark suggests, it is actually a good habit to do a preliminary 250v test before undertaking a 500v test and accidentally frying some equipment vulnerable to testing that you had omitted to identify was still connect to the circuit. I think not damaging a customers equipment is very good justification.

Doc H.

 

[Robin Spark]

I got blamed for damaging a customers combi boiler a while back when I did some work and his handy man mate said that it was probably due to me testing the cct, thing is I knew this couldnt have been me. When I went back to the customers property to have a look the kitchen ceiling had just been reboarded and now there was no supply to the boiler FCU. Not my problem I told him, you have obviously pulled a cable out of a JB from above the ceiling. I didnt offer to sort it as it was a nightmare to get the first lot of money out of him!!!