R1&R2 and Insulation Resistance Test with fixed appliances

[phawk]

Can anyone help me, I've been asked to do an inspection on a property that is on a single 32A ring, including the kitchen. The appliances are all integrated and aren't spurs. Is there a way to perform the test with these appliances in place?

Thanks!

 

[TPES]

Can you not get to the Sockets to unplug all appliances?

 

[phawk]

No they are wedged in. It's a posh kitchen and the owners don't want me pulling their integrated appliances out. Someone was telling me I could do a combined N/L to CPC test instead but I don't know if this would work or is even compliant to regs.

 

[TPES]

As long as its noted on the report that the appliances can not be unplugged then you need to IR test L-N to CPC on that ring. Just note it as a limitation, but if you can't get to sockets then I think that in it's self may warrant a code.

 

[TPES]

As long as any limitations are agreed with your customer and wrote on the report then your back is covered.

 

[phawk]

Ok thanks a lot. What can I do regarding the R1&R2 test as there are loads on the ring, will this not throw my readings out?

 

[TPES]

Your R2 maybe higher due to the earth on the appliances

Do your end to end and see if your R2 is alot higher than the normal 1.67x, you probably find there's not much in it

 

[phawk]

Thanks very much I'll test as suggested and note it on the PIR.

 

[telectrix]

most appliances have double pole switches, so, as long as they are switched off, they should not affect your readings. R1+R2 should read (r1+r2)/4. fridges and freezers though could be a problem, as they don't have an ON/OFF switch.

 

[TPES]

Unless the socket that the appliance is plugged into is a spur off the ring then the R1+R2 will be higher than the calculated method. The fact there is no method of isolating each appliance without the use of a tool (Removing integrated appliances) would be a concern to me.

As tel says be sure the appliances are in the off position, on the ones that can, I'd also do IR at 250v first to see if there is any load affecting those readings, if not then your safe to go up to 500v