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Can anyone who is or knows about being an electrician, tell me what one should expect to find when you do an IR test on the supply itself?
Basically I went to repair a cooker with hob problem. Straight forward hob element fit, no rocket science needed.
Anyway, when I IR’d the appliance while still hard wired into the spur, it gave a reading of 00.1mohms. When I disconnected it it from the spur it was over 200mohms. So I put my probes on the terminals in the spur (no cooker connected) and got the 00.1mohms reading again. That was on both L to E and N to E. Now I’m no spark, but isn’t that a fault? It was missing one cable clamp screw and one plate securing screw, so clearly not the best care taken when the cooker was initially installed.
There was no isolation switch for the cooker and the dedicated switch for the cooker in the CU didn’t turn the power off to the cooker, so I had to turn off the entire power to the house before starting any work on this appliance.
The customer also said that her last cooker she had in that spot used to give them shocks.
Re: Cooker spur point.
If you have only turned off the main switch in the house then you are IR testing the whole house which won’t really tell you anything without disconnecting every single appliance and light bulb etc first.
Jem
Edit: In the case of testing the whole house you would want to make sure that you short L and N together otherwise you could potentially damage the electronics in something else, also only use 250VDC for the same reason.
Re: Cooker spur point.
I did only use 250v and cookers should be on their own main supply, shouldn’t they? They have their own fuse and a supply that runs separately to the ring main.
Re: Cooker spur point.
Good lord!….. Get a Part P spark in to put in a dedicated cooker spur/consumer unit MCB in. Customer getting shocks? No isolation switch? You’re heading for trouble here…… 😕
Re: Cooker spur point.
It’s not my trouble, surely? But yeah, no isolation switch and the switch in the CU labelled ‘cooker’ didn’t turn off the power to the cooker. The shocks were from when they had a different cooker installed.
Re: Cooker spur point.
If it is a low enough power then there is nothing wrong with running it off a 13A plug but no matter what it is run from there has to be an means of isolation within 2 meters of the cooker.
As I understood it you shut the power off by turning the main switch in the house off, this would still leave every other circuit connected in parallel to the cooker circuit so your IR test would not tell you much useful info.
An earth loop test would be more useful than an IR test if the customer is getting shocks (although I read that as being the cooker before the one that you are replacing in which case the issue may have been sorted).
You really need to have more knowledge about earthing and protection systems before you can say whether or not it is safely earthed.Jem
(looks like you posted while I was writing this).
Re: Cooker spur point.
Hollytree_Technical wrote: but no matter what it is run from there has to be an means of isolation within 2 meters of the cooker.
An earth loop test would be more useful than an IR test
You really need to have more knowledge about earthing and protection systems before you can say whether or not it is safely earthed.
.I actually intend on gaining schooling on domestic electrical work. My cousin is a spark and he offered me some mate work, so I may take him up on that a day or two a week.
The within two metre from the cooker thing, is that mandatory? I checked everywhere around the kitchen for an isolation switch.
Re: Cooker spur point.
The 2 meter distance is not mandatory but it is strongly advised in “The On Site Guide – Appendix H” and I am lead to believe that it is also mentioned in “Electrician’s Guide to the Building Regulations” although I don’t have a copy of the later so can’t check.
I perhaps should have said that “there should be a means of isolation within 2 meters of the cooker”.
Jem
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