DIY PV install

Can you point me in the direction of any suppliers up north if ya come across any. Thanks

Cables feeding the meter and consumer unit are undersized too and need replacing. It can be done when you get the neutralising sorted. Unfortunately you will also need the Esb.

First point of contact is a spark.

Fair play welshchris77, great thread. We did a self-install here too, but that wasn't as large as yours. I would suggest, if you havent already, is to have an registered electrician lined up to that will sign the NC6 documentation for the ESB to notify them that a solar installation will be taking place. Maybe your friend who is the installer?

I see that you have one of the old Analog electricity meters installed. The ESB will probably want to upgrade that to a smart meter. I know a few folks who got away with not getting the upgrade: the old analog meters run backwards when you produce excess electricity, basically giving them a very generous FIT rate.

If it's a 1967 model it will spin backwards. Not mine of course, just someone I know :)

Most of the inverters installed in Ireland are made in China..

I would suspect this is the case but would hope and expect the certified installers and their suppliers conduct some form of quality control on these units though and are likely fully CE marked. Not sure if the same can be said of the ones from Alibaba or other Chinese outlets. I will be doing a ground mounted install in a field so don't care so much what catches fire out there.

Nice one! Good to see some others have tried it. I think it's definitely worth the risk. Just thought I'd put the feelers out to see if any horror stories. Thanks!

 "I found that Solis recommends 100a RCD’s,"

Have you confused 100amp & 100mA ?

It's not great really having a 6 sq cable protected by a 63 amp mcb.

Another problem is that a type s rcd is time delayed and doesn't protect life, add to that 100ma and you're seriously breaching regulations.

Some light reading.

You could do that but a fault in one then kills power to both. It would cover the overcurrent issue though.

The problem with the type S rcd is that it just won’t trip in time.

@welshchris77 The Solis has a built in residual current monitoring unit so you should double check if you actually need external RCD protection. If one is required they recommend it's type A. I've seen them installed with only a Type B MCB at the CU. (40A recommend by Solis for a 6K)

From my reading of the code of practice there's not a requirement for another RCD if the inverter has the required protection built in.

"4.6. AC Electrical System

AC Electrical System shall meet the following requirements:

• Type B RCD The AC system must be tested and certified by a Registered Electrical Contractor and a Safe Electric certificate must be provided.

• The AC system must comply with I.S. 10101

• Where an RCD is used for protection of the PV a.c. supply circuit, The RCD shall be of type B according to I.S. EN62423 or I.S. EN60947-2, unless:

- the inverter provides at least simple separation between the ac side and the dc side or

- the installation provides at least simple separation between the inverter and the RCD by means of separate windings of a transformer; or

- the inverter does not require a type B RCD as stated by the manufacturer of the inverter.

• An AC isolator (2 pole, switching live and neutral) must be installed between the inverter and the consumer unit, and accessible from the inverter location

• Where an RCD device is installed on the AC circuit feeding an inverter, the RCD type must be selected according to IEC TS 62548:2013.

• AC isolator must be labelled – “PV System MAIN AC Isolator” or an equivalent statement.

• The main incoming point of the dwelling (typically the meter box) must contain a warning label indicating the presence of a separate source of electrical supply to the building"

(Disclaimer, the regs have chopped and changed so much lately none of the above may still be the case so feel free to correct me if so. 👍️)

I already did highlight it in bold. They say 'Where an RCD is used/installed' which would indicate it isn't mandatory.

Like I've said, I've seen them installed with only the correctly sized MCB. Regs may have changed since like I said but this is where you'd need to talk to a sparks/engineer who's familiar with exact inverter models and current regs.

"MCB

• Usually an MCB in the consumer unit

• Feeds local grid via consumer unit and surplus exported

• Generally no RCD required RCD may produce false tripping however where required consider 100ma"

This is actually a really critical document as it explains what we were asking ourselves about 3 months ago when @micks_address had some trips.

I was of the understanding that a PV inverter's AC side would by fully isolated from the DC side and hence the DC loss to ground when it was raining was non-comparable to AC leakage. After all you would think that if DC current was lost off the positive terminal of a connection it was effectively untraceable as the DC supply was coming off the solar panels and then inverse of the DC loss would not be seen on the negative terminal, hence showing an imbalance as you would do with AC. But no, that's not true in an AC connected inverter.

It seems that transformerless inverters oscillate the DC supply at around half the AC input voltage (section 2, page 4) and as a result there is AC current present which is capacitively coupled between the silicon panel element and the frame of the panels and the mount and then the roof. They all add-up to become "Cpe", the parasitic capacitance.

During times of very heavy rain on the panels the Cpe increases significantly due to the surface-area of then panels and it causes a leakage trip on the circuit RCD.

The workaround mentioned is to use a correctly sized compensation capacitor on a quad-pole RCD rather than a dual-pole RCD. IE, one of these:

So yeah, @allinthehead, thanks for posting that!