 |
IET |
 |
 |  |
|
search :
help :
home
|
||
|
Latest News:
|
|
|
|
Topic Title: Solar PV installation and main equipotential bonding Topic Summary: Created On: 10 July 2012 07:33 PM Status: Post and Reply |
Linear : Threading : Single : Branch |
 Search Topic |
Topic Tools
|
 10 July 2012 07:33 PM
|
|
|
Had a meeting with a Solar PV sales company to quote for doing the electrical side.
I said that during the site survey the main equipotential bonding will need to be checked and they said that in the last 3 years of doing this none of the installation companies they have used have asked about this or checked, also they said it is comon practice to put the generation meter, isolator and a 2 way DB in the DNO meter cupboard as 'it saves any internal electrical work, only in the loft' I argued that that box is reserved for DNO equipment only. They are looking for a new company as the existing company's prices have sky rocketed, they said 2 of us should be able to do a standard size house within 30 mile radios in a day easy - is this correct? Is omitting the equipotential bonding and putting all the equipment in the meter cupboard standard practice of PV installers ?!! |
|
|
|
|
|
10 July 2012 07:43 PM
|
|
|
Whether the array(framework) needs equipotential bonding depends on a number of factors. If they are out of the way on a roof and cannot be touched from say a velux and are not extraneous then they may not need bonding. There is a flow chart on the DTI Guide v2 (the current one) which gives guidance. The DTI Guide v3 draft is also around which relaxes the requirements to bond a bit and many are working to it already.
Until today I would have said it was very rare to put PV equipment equipment in the meter cabinet, but there is a thread here: http://www.electriciansforums....-fitted-meter-box.html with a picture showing it might be more common than I thought. Alan C will no doubt offer stern words! Regards Bruce |
|
|
|
|
|
10 July 2012 08:07 PM
|
|
|
Bajb,
No, I mean the equipotential bonding to gas a water....not the PV frame work.... |
|
|
|
|
|
10 July 2012 09:59 PM
|
|
|
Well they didn't on my install ... but then I don't have a meter box and I'd upgraded the earthing & bonding myself before they got there so perhaps I didn't give them the chance! Sounds very rough to me - I don't see how they can claim BS 7671 compliance without ensuring the bonding is adequate and I've a feeling that BS 7671 compliance is a requirement of G83. - Andy. |
|
|
|
|
|
10 July 2012 10:44 PM
|
|
|
They are looking for a new company as the existing company's prices have sky rocketed, they said 2 of us should be able to do a standard size house within 30 mile radios in a day easy - is this correct? q] Are you installing all the brackets and panels or is someone else doing that and you just wiring the panels to the inverter and then down to the consumer unit via the dc and ac isolators and meter? I allow 3 days min, 3 men for 2 days and 2 men for the last day (8 days in total) for an average house for a complete install. Fitting the brackets and rails take ages if you want the job to look good at the end and if its raining or windy lost time soon mounts up and dont forget you have to hump all the panels up to the roof. If someone else is fitting the mounting stuff and panels and connecting them together on the roof you need to be careful and make sure they have tested every panel and recorded the serial numbers and results etc. a faulty panel will be an ass to find and be even more careful if they have dropped the DC tails into the loft with out crimping the ends on them. But if that is all done for you and all you have to do is mount the inverter, isolators, meter, CU etc and connect it up then a day for 2 men should be more than enough providing the cable route from the loft to the CU is straight forward |
|
|
|
|
|
11 July 2012 12:56 AM
|
|
|
I've been doing Pv for two years now and get asked to look at jobs quite often and not only are some jobs unbelievably rough ,poorly presented but I'd say over 50% were signed off with no or incorrectly sized bonding to utilities etc and some of these are being done by reputable Electrical firms.
There's also the big debate over bonding arrays and I think alot of people are confused about whether or not it is required Its actually very straightforward if its a Transformerless inverter then they need to be grounded ie 10mm earth from array frame to its own earth rod in the case of TNC-S or to the MET if TT / TNS this is recommended by all inverter manufacturers instructions. Bonding of the array if its reachable from within the property is just the same as bonding structural steel and in my experience rarely needed The trouble is people are reading the notes on Bonding arrays and then deciding as it cannot be touched then it does'nt need to be done |
|
|
|
|
|
11 July 2012 05:46 PM
|
|
|
Thanks for the replies, Roofer fits rails, gets panels ready, we test panels and connect them while roofer bolts them to frames, then onto isolators, inverter, dbs... I have seen some dog rough efforts so far, A local company clips SY cable with black clips down the front of the house....ughhhh They are looking for a new company as the existing company's prices have sky rocketed, they said 2 of us should be able to do a standard size house within 30 mile radios in a day easy - is this correct? q] Are you installing all the brackets and panels or is someone else doing that and you just wiring the panels to the inverter and then down to the consumer unit via the dc and ac isolators and meter? I allow 3 days min, 3 men for 2 days and 2 men for the last day (8 days in total) for an average house for a complete install. Fitting the brackets and rails take ages if you want the job to look good at the end and if its raining or windy lost time soon mounts up and dont forget you have to hump all the panels up to the roof. If someone else is fitting the mounting stuff and panels and connecting them together on the roof you need to be careful and make sure they have tested every panel and recorded the serial numbers and results etc. a faulty panel will be an ass to find and be even more careful if they have dropped the DC tails into the loft with out crimping the ends on them. But if that is all done for you and all you have to do is mount the inverter, isolators, meter, CU etc and connect it up then a day for 2 men should be more than enough providing the cable route from the loft to the CU is straight forward |
|
|
|
|
|
11 July 2012 10:03 PM
|
|
|
Doing the bonding to gas water and array (if required) and also the inverter in loft can be done in a day normally.
The electrician would arrive and firstly install the dc isolator and roofing team would take dc cables out to where electrician instructs, our roofers connect panels as they install and before leaving the spark checks the array strings are correct.however the sparks do tend to consentrate on the pv installation so that there is enough sunlight to check system is working etc. The bonding is done to gas, water after and only a few times have we had to return to finish bonding. When roofers are doing the array we ------------------------- Dougie Power Plus Electrical.co.uk My mission is to live as long as possible......so far so good! |
|
|
|
|
See Also:
|
|
| Technical discussion forums |
|
| · | Wiring and the regulations |
| · | Built environment |
| · | Design and production engineering |
| · | Control and automation |
| · | Communications engineering |
| · | Information technology |
| · | Energy |
| · | Transport engineering |
| · | Airfield engineering |
| · | Electronic engineering |
| · | Management in engineering |
| · | Consumer technology |
| · | Other and general engineering discussions |
| Professional and career discussion forums |
|
| · | Feedback and questions |
| · | CEng, IEng, EngTech and other professional registration matters |
| · | Savoy Place Virtual Club |
| · | Student and apprentice discussion forum |
| · | Young Professionals Community |
| Archived categories |
FuseTalk Standard Edition v3.2 - © 1999-2013 FuseTalk Inc. All rights reserved.
