Mem nightmare

[Coleman]

Hi lads
Can anyone help? I've wired a pv circuit to a mem cu 10 way it's tripping everytime some of the appliances are switched on

 

[telectrix]

neutral in wrong bar?

 

[Coleman]

That's what I thought but this board is weird, the bus bar goes from the rcd to the rest mcb's and the neutral bars are separate

 

[mechelec]

Did it do it befoe you connected your system? if not look very carefully at what you have done. Try disconnecting your system and see if it stops.

 

[Coleman]

It didnt apparrantly I told her to switch off the e/supply from the inverter but not the mcb and still tripped when sockets were active

 

[GaryM]

What's the make up of the consumer unit? RCD for all circuits, two RCD's for a number of circuits each?

Is the inverter suppied via an RCD which supplies other circuits?
It certainly sounds that way so leakage from the inverter coupled with leakage from additional appliances might be just enough to trip the RCD.

Something else to consider though - an inverter can take up to 5 seconds to disconnect. If it's supplied from an RCD which also supplies other circuits that rely on a disconnection time of 0.4 seconds then those circuits could potentially stay live until the inverter disconnects leading to a potentially lethal condition.

 

[clicon357]

I'll admit I know jack about PV installs (other than a mate has just had one done!). But I wonder if the inverter issue is going to become more of an issue i.e. tripping. Maybe the Merlin Gerin Si type RCDs I've posted up about before might become more common?

http://www.engineering.schneider-el...n_against_nuisance_tripping_voltage_surge.pdf

 

[Coleman]

Thanks for all the advise lads
I went there tonight to see if I could solve it and it turned out that the problem was on the hob, everytime the customer turned on the hob it tripped the RCD with all other circuits off including the pv circuit, all though it's weird after me installing it only yesterday! Is there anyone else here installing pv?

 

[GaryM]

Did you see my point above about installing an inverter with an up to 5s disconnection time on a common RCD that shares circuits required to disconnect in 0.4s? It's dangerous.

Also, there's an excellent PV section on this forum.