A question on PV testing

[Paul.M]

Hello gents, I don't normally pop in here but I believe its the best place to ask a question on behalf of a friend. And it is a friend, I don't do PV.



Q. My boss as told me not to waste time testing the DC side of PV installations, only the AC.


My friend has not put his signature on any certs, he knows better than that as an I&T.

Rock and a hard place, what would you do? What are the legal views on this? Warranty on the inverter? No win no fee culture?



Any advice on this topic will be appreciated, thank you in advance of your input.

 

[GaryM]

Insulation resistance, R+ + R- (in the same way as R1+R2) and polarity should surely be carried out?

 

[Paul.M]

Insulation resistance, R+ + R- (in the same way as R1+R2) and polarity should surely be carried out?

Thank you Gary but the question is:- If my employer doesn't want me (friend) to carry out any tests on the DC side of an insulation. What can I do?

Thanks for your input Gary.

 

[GaryM]

The only cert you'll be completing then will be an EIC which covers only the AC side. In that case, sign it. Your doing nothing wrong as its not like your creating a cert for the DC side and making figures up is it? Or are you (your friend)?

 

[yellowvanman]

When it comes to an assessment though the boss will need to produce some dc test certs!

 

[Paul.M]

The only cert you'll be completing then will be an EIC which covers only the AC side. In that case, sign it. Your doing nothing wrong as its not like your creating a cert for the DC side and making figures up is it? Or are you (your friend)?

Gary this isn't me. It's not like a sketch from a 80's sitcom saying:-

Doctor "my friend" has warts on his 'rounded door handle'!

It is a friend that may lose his job if he asked this question on this forum (it happens, trust me I've fallen victim of it).

Ok let me refraise the question:-

What DC tests do you have to provide on a cert after completion? Is it a legal requirement under the several PV regs? What is the legal standing of my inspector & testing friend?

 

[TedM]

To comply with MCS rules you need to carry out the inspection & testing as detailed in the current DTI PV Guide v2.

The inspector must sign the test sheet (Appendix C in the DTI Guide) which includes these DC tests:

- Physical separation of a.c. and d.c. cables
- d.c. switch disconnector fitted (to IEC60364-712.536.2.2)
- d.c. cables - protective and reinforced insulation (only relevant if required)
- All d.c. components rated for operation at max d.c. system voltage (Voc stc x 1.25)
- PV strings fused or blocking diodes fitted (only relevant if required)

There are then separate tests for each string to record Voc and Isc under solar irradiation.

Failure to comply with these requirements could render any MCS certificate issued for an installation invalid and lead to the owner not being paid FiTs.

 

[Paul.M]

TedM thank-you for your most helpful post that would have taken you time and effort. Thank you sir.

 

[grandfortune]

I do it, but im with your boss, cant see why. most installs are small runs cable very tough your not running though many walls and joists where they could be nails, also you can usually see 90% of the DC run. any one had any problems with there DC side of things i very much doubt it.

but its at YOUR risk