PV & Micro- Gen

[T&Earth]

Hi Guys

Been reading various post regarding PV systems etc where like me other forum members have very limited experience with these systems. I will not touch anything to do with that side for obvious reasons, but have been called to look at problems not relating to this eg light / power etc which would require the CC cover to be removed.

Could any of our more exprienced members give an idots guide to working on these

Any help would be greatly appreciated
Many Thanks

T&E

 

[sedgy34]

Just don't mess with the Pv radial if your there to do other works if you isolat DB the Pv will reset and automatically come back on when power is restored

 

[BMelectrics]

If you go into the attic (or where ever the inverter is) there should be 2 isolators.(AC and DC). If you isolate these then there will be no electricity flowing to the consumer unit, and it will be safe to work in it without fear of a dual supply.

When you have done your work, turn these isolators back on, and the system will 'reboot' itself automatically.
It usually takes about 3 minutes for the PV generation to start again (providing the weather is bright enough)

Another way to know if the PV system is generating without having to go back into the attic is to look at the PV systems incoming meter that is there for the feed in tarriff. After 3 minutes, if the red light is flashing intermittently then the panels are generating, if it displays a solid red light the system is in standby (bad weather, night time conditions) and will start up again when the conditions are right.

 

[BMelectrics]

remember to isolate the radial circuit with the AC and DC islolators at the inverter, there is still current for the capacitors in the inverter.....ouch

 

[pjcomp]

If you go into the attic (or where ever the inverter is) there should be 2 isolators.(AC and DC). If you isolate these then there will be no electricity flowing to the consumer unit, and it will be safe to work in it without fear of a dual supply.

There should also be an AC isolator by the CU. Switch off the AC and DC in the attic and the circuit from the CU to the attic will be a 240V AC live cable.

PJ

 

[GaryM]

Isolate AC isolator first, followed by the DC isolator. When switching back on do the reverse - DC isolator first then AC isolator.

 

[T&Earth]

Hi Guys

Thanks very much for taking the time to reply, some good advice.
Cheers
T&E

 

[BMelectrics]

yes, as GaryM says, isolate AC first then DC at inverter, and then if there is another isolator at the consumer unit, isolate that aswell. Sometimes the isolation at the consumer unit is in the form of a small garage unit DB. The breakers can be locked in the off position in these also. If some cowboy hasnt put any lockable isolation at the consumer unit end, just isolate in the attic.

The Pv circuit should be fed from a 16A breaker in the house consumer unit, but sometimes I have stumbled across installations that have been doubled up in the main switch :rant: If this is the case then the main fuse will have to come out!

 

[GaryM]

but sometimes I have stumbled across installations that have been doubled up in the main switch :rant: If this is the case then the main fuse will have to come out!

So no protection for the AC side? Or a supply from the main switch to a 2 way CU?
Either way, this is why MCS is in place but it seems there's cowboys in most trades

 

[BMelectrics]

So no protection for the AC side? Or a supply from the main switch to a 2 way CU?
Either way, this is why MCS is in place but it seems there's cowboys in most trades

Yeah, Iv seen it being doulbled up in the main board coming out to a small 2 way CU, Protected with an RCD and 16A breaker. But the point of the matter is the fire hazard in the main CU ie: doubling up conductors of drastically different sizes.

 

[AndyL]

There should be AC isolator next to the CCU, isolate here if working in CCU then you dont need to go near the loft or touch the DC side and then remember to turn back on when you're finished and the PV will restart itself