advice for 3 phase connection

[Maff]

We been asked to quote a 10KW feild mounted system to connect in to a 3 phase supply, All the DC side is relatively straight forward. As a first 3 phase job am wondering a few things. 1)What cable to link the inverter to the 3 phase meter then to the isolators/RCD(TL inverter). does it have to be 4 core swa? or does anyone do 4core T&E
2) Do we use a 100mA rcd(4pole), or a 300mA with an MCB for each phase.
3) Each phase terminates from the service head into henlys, then each henly feeds a ccu, is it ok to inject straight into each henly?
Thanks in advance for your thoughts

 

[andyemms]

I would be interested in seeing any comments from more experienced installers. I have a similar job coming up and will watch this space....

 

[Worcester]

What's 4 core T & E?

We tend to use 5 core SY 6mm2 to link small three phase inverters to the 3 phase breaker it i'ts not more than a cuple of meters.

The only thing that was here before was the incoming 70mm2 cable and the tall hager distribution board on the right, all the rest is new. - We moved the incoming 70mm2.

There's about 7 man days work in this room alone:



Free pat on the back to anyone who can tell me why this installation is producing no power (apart from it's dark )

Before:

 

[SolarCity]

Cracking looking install. What's with the two meters?

 

[Maff]

Sorry,dont know where 4 core T&E came from. Is it ok to put 6mm Singles in trunking as all the switchgear/meter RCD enclosure etc will all be together next to the inverter or is that outside the rules.
We are only using one inverter(SB 10000 TL) The main thing I am unsure about is the RCD/MCB size, type, and arrangement as this can affect the pricing.

 

[electrical4]

All the isolaters are off ??

 

[SolarCity]

DC switch on the inverters not plugged in?

 

[Worcester]

BiggsSolar got it! - Forgot to put the Solar Switches back in! (Removed them safely to the car so that no idiot could turn the system on accidentlly !!!) Then when got home realised I still had them, when sparks called and said we're only showing 0.05kW!

Cracking looking install. What's with the two meters?

Thank you for the comments!

Top left is export, right hand one is local consumption as main meter 250m away at DNO connection (hence the 70mm cable) Main / DNO meter now tells them night time consumption, and local meter tells them local consumption so that they can offset real consumption as a business expense as the premises have a sub tennant that is getting their electricity 'for free'.

They are ISKRA CT meters, real simple to install just be careful - the 'post install' one comes with massive CT's the unbroken loop version is about a quarter of the size.


That's our usual standard and is one reason we aren't the cheapest!

We used S/S tray on the roof to handle the cables, and if you look closely every cable is labelled with it's string reference, which ties up with labels on the roof also.


Every panel tested prior to install (we have a new test rig that made testing each panel incredibly quick - photo's to follow soon) and I could tell you the serial number and location of any panel on that roof, so if we ever got a product recall (they had a big one recently in germany) we'd knoe exactly which panels were affected.

That's an Olympic Starndard Equestrian Centre, hence we had to avoid all the skylights and all natural light had to go through unobstructed.

Just inder 200 panels installed on the roof by three guys in 5 days and electrics (including stringing etc) took one sparks 10 days.

 

[Ramjam]

That's a great looking job and an example to us all.

I've got two or maybe three such install to do, one for myself and another two in the sales order pipeline. I'm currently trying to complete the "Generator new connection application form" from ENO and to be honest I'm struggling. I spoke with my DNO who admitted that even if I completed it correctly they wouldn't understand and to have a crack and send it in but to be honest I'd be much happier if I understood it and completed it correctly.

Any advice????

 

[Worcester]

@Ramjam, we primarily work with WPD (ex Central Networks) and they were very helpful with our first one. We now just copy that model for each of them. The problem is the form is there for ALL types of generation and a lot of it isn't relevant in Solar PV systems, - about 50% of the Part 1 is blank , and all of Part 2 is blank. So although it looks daunting in practice they are quite straightforward.

 

[SibertSolar]

Very nice/professional install Worcester!

 

[Maff]

Thats almost PV ****

 

[russgibb]

Hi guys.
Very professional install, I must say.
We're helping a client out with their DNO G59 new connection form and are struggling a bit. We only distribute Mitsubishi PV (in Scotland), not install it, so it's new to us (but we want to win the large order!).
Would it be at all possible for you to post a copy of a typical form (obviously sanitised to remove any confidential information), because frankly I'm a bit lost with it all.
Regards,
Russell

 

[Toonlad]

just out of interest,how do you commission this size system. I only ask as my firm is going to send me on a g53 2-1 course next month, and i don't really like going into something totally blind. I lke to have at least the fundamentals of what procedures, test/and other bits n bobs. If you dont want to go into specifics on the forum then that's fine.

Nice instal BTW.

ATB
Steve

 

[Worcester]

Steve,

Same as any other, unless you're using a dedicated G59 relay, then it's a simple case to test all the parameters that the relay should trip on (and not) at the same time as having it witnessed (over / under volatge, over under frequency, time to trip etc all as per the G59 spec). - Best to get a specialist firm in to do the testing unless you've giot a spare £11k to buy the testing kit. Usual charge about £500 / day plus another £500 or so for the DNO to witness the tests.