It rather depends exactly how and what the PV circuit is wired in. If it is wired in armoured cable from the AC isolator to the consumer unit then it is mechanically protected and this solution would probably be acceptable. If it is not wired in armoured cable then I would have thought it would need RCD or RCBO protection, but as I say I am not an electrician.
RCD tripping on new Consumer Unit
- Thread starter billywolfe
- Start date
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Hi Peter . It is not armoured cable.
The electricians have been this morning and done the following :-
The solar circuit on a 20a MCB has been taken out of the bank of MCBs protected by a 30ma RCD. So the RCD will then protect 5 "house" circuits - 2 lights, 2 sockets and 1 cooker. The 20ma MCB to which the solar is connected has been slotted into the CU as an unprotected MCB i.e. NO RCD PROTECTION.
I did speak to PowerOne technical support earlier this morning and they confirmed that this is an acceptable solution. Each installation is different and if the electricians had decided that RCD protection would be required, then the suggested one would be a 300 ma RCD (type AC I think)
Correction to what I said above : My a/c cabling from the inverter in the loft down to a cupboard where the CU is housed (I live in a bungalow) is attached to the surface of the wall in the loft and is enclosed in trunking for the section which is on the wall. (not the rest of the run along a joist which is about 4 metres)
I hope this is the end of it....I will post again if I have further RCD trips.
Thanks to all who contributed here....I hope the posts here help someone else in the future.
The solar circuit on a 20a MCB has been taken out of the bank of MCBs protected by a 30ma RCD. So the RCD will then protect 5 "house" circuits - 2 lights, 2 sockets and 1 cooker. The 20ma MCB to which the solar is connected has been slotted into the CU as an unprotected MCB i.e. NO RCD PROTECTION.
I did speak to PowerOne technical support earlier this morning and they confirmed that this is an acceptable solution. Each installation is different and if the electricians had decided that RCD protection would be required, then the suggested one would be a 300 ma RCD (type AC I think)
Correction to what I said above : My a/c cabling from the inverter in the loft down to a cupboard where the CU is housed (I live in a bungalow) is attached to the surface of the wall in the loft and is enclosed in trunking for the section which is on the wall. (not the rest of the run along a joist which is about 4 metres)
I hope this is the end of it....I will post again if I have further RCD trips.
Thanks to all who contributed here....I hope the posts here help someone else in the future.
It would be interesting to know what happens if you turn off your main switch while the solar system is generating power.
If there is still some power to the house, enough at least to light on lamp, then the invertor has not shut down on loss of network supply.
If the network supply was to fail the invertor would not shut done and would very likely continue back feeding the network and thus be a hazard to DNO staff working to repair the network.
If there is still some power to the house, enough at least to light on lamp, then the invertor has not shut down on loss of network supply.
If the network supply was to fail the invertor would not shut done and would very likely continue back feeding the network and thus be a hazard to DNO staff working to repair the network.
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The Inverter units are more complex than you give them credit the incoming supply must meet set parameters or they shut down and indicate a fault. They will shut down in the event of undervoltage/overvoltage/frequency distortions. This is a requirement of any grid connected inverter under G83/G59
I am aware that there are strict rules. I am also aware that some solar systems will power the house during a power cut. Maybe they do not conform the regulations applicable to grid connected systems but can be connected in a way that means they will feed the grid "by accident".
Firstly for the RCD to trip there is an inbalance in the circuit so there may be a leakage to earth.
As RCD's do not detect Short Circuits or overloads as this is the MCB's job.
Try isolating each circuit and see if it trips ie disconnect Lights first then sockets etc
Also see if there are unusual high resistance readings by doing a continuity test on all circuits anythin greater than (1.00 ohms) on the ohms reading and also an insulation resistance test to check the integrity of the sheath and insulation set to 500V on voltage tester settings and look for >1000 on the readings.
Its all about fault finding in all electrics so elimination will get you nearer.
You may have a faulty RCD you never know
As RCD's do not detect Short Circuits or overloads as this is the MCB's job.
Try isolating each circuit and see if it trips ie disconnect Lights first then sockets etc
Also see if there are unusual high resistance readings by doing a continuity test on all circuits anythin greater than (1.00 ohms) on the ohms reading and also an insulation resistance test to check the integrity of the sheath and insulation set to 500V on voltage tester settings and look for >1000 on the readings.
Its all about fault finding in all electrics so elimination will get you nearer.
You may have a faulty RCD you never know
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