How to test supply type TT, TN, or IT? (Solar panel install with battery)

[ericmark]

I would say not TT, as if the grid supply is on then TN-C-S and if not since the supply is within the premises even if there is an earth rod it would not be TT.

However since within the premises then no where is the earth and neutral combined so if a TN system it would be TN-S, however it depends on where the supply is lost, if after the point where the earth and neutral are combined then it would be an IT system. However since all done within the inverter I have no way of knowing if the neutral and earth are linked when the grid supply is lost.

All I know is a compliance certificate has been issued.

I think the chance of loosing the supply and at the same time having a fault which needs an earth to make it safe is very unlikely, but it could easy happen that some one working on the house turns off the grid supply isolator the question is if there is anything in the inverter which will then bond neutral and earth making it TN or is not then it a IT supply. Other than bathrooms is that permitted? I know a shaver socket outlet is IT but I am looking at central heating plus 4 sockets normally supplying freezers.

I can't see an inverter linking neutral and earth but it may.

 

[Murdochcat]

Do you not have an EIC ?

 

[ericmark]

Yes for all the good it is, no RCD trip times, no resistance entered for the earth rod, this

Is all it says, two RCD sockets fitted in a kitchen so notifiable, and no test results for them. I saw them measure the earth rod resistance, but no figures entered. And I would have thought serial number of the tester should be entered not just make and type?

I don't think "KEWTECH KT64DL" is a serial number? They all seem to have the same serial number which seems odd.

The supply type I not has not been entered and the boiler no longer RCD protected, I did try fitting a RCD FCU but it kept tripping, I assume some thing to do with being an inverter supply, but I should not need to fit the RCD for the central heating it was RCBO protected before it should be RCD protected now.

I read in my old 7671

411.6.3.1 Where an IT system is used for reasons of continuity of supply, an insulation monitoring device shall be provided to indicate the occurrence of a first fault from a live part to an exposed-conductive-part or to Earth.
This device shall initiate an audible and or visual signal which shall continue as long as the fault persists.
If there are both audible and visual signals it is permissible for the audible signal to be cancelled.

I can't see how my system complies, so assume rules have changed? Or I could not have been issued with a compliance certificate?

 

[Murdochcat]

You are correct about the missing serial number for the tester.

What is circuit 1?

Which CPS do they claim to be members of?

Seems all rather half baked IMHO

 

[ericmark]

NAPIT the company who fitted the solar panels seems to be an administration company you employ other companies to do the work, this is not what I thought was the case to start with, and I was sent a pack as an email 57 pages of it which includes the installation certificates and compliance certificates, Powis website confirms the work has been registered with the LABC but signatures are type written.

I would have expected a hard copy with actual signatures.

In the main the work seems good, but it is the UPS bit I am not so happy with, to my mind pressing a button to isolate supply is wrong, I would have expected some thing I can lock off, and I can't lock off a push button. It may well be that there is an isolator built into the inverter, but the battery is in front of the inverter so can't reach it, also it seems they use plugs and sockets so likely it can be unplugged, but again the battery is in front of the inverter so no access.

 

[bernardgreen]

Put solar generated electricity directly into an immersion heater in a thermal buffer store, no invertors or connection to the rest of the electrical installation.

 

[Murdochcat]

You are correct about the missing serial number for the tester.

Which CPS do they claim to be members of?

Seems all rather half baked IMHO

 

[EFLImpudence]

NAPIT the company who fitted the solar panels seems to be an administration company

 

[ericmark]

The company we paid our money to seems to engage sub contractors to do the work, they are it seems office workers and salesmen.

 

[EFLImpudence]

NAPIT is one of the schemes.

 

[Murdochcat]

On the EIC, what is the company name and address.

It’s not NAPIT btw

 

[ericmark]

It seems it is TN-S once the grid connection fails, new grip now, they were arranging the feed in for us, now they say the law has changed and they can only get a feed in tariff if one has a smart meter, they say the law is 6 weeks old, so to date fed in 166 kWh seems we have given it away, so only £15 but 28th November before we can get a smart meter fitted.

 

[Why Not Indeed]

Bit more than 6 weeks methinks, try 4.5 years:

Feed-in Tariffs (FIT)

An overview of the Feed-in Tariff (FIT) scheme administered by Ofgem: who it's for, how it works, and roles and responsibilities.

www.ofgem.gov.uk