Hi.
I have a UK customer that has an agricultural building that will have a Diesel TPN generator supplying a corn dryer electrical installation.
He also wants a solar array (2kw) off grid battery backed system to supply local lights, small power, trickle charge the generator batteries (from standard 23vAC battery charger) as well as supply an intruder alarm and possible cameras.
The Invertor and array will sit on and in a metal container, outside the main building.
There will be no AC electrical connection between the Diesel and the PV, and there will be an interlock that will isolate the PV supplied battery charger from eth Diesel batteries when eth Diesel is running and charging its own batteries.
IEE, is very light on PV earthing and electrical arrangements. I have done some digging and i can see that there is an SPD risk assessment requirement, but seemingly as long as Lcrit is less than 115m I don't need anything which i think is odd.
Am looking for some install guidence if any available please?
I assume earthing is a buried electrode, with marshalling between the generator and metal services, building fabric etc. Sizing based on prospective fault current form eth invertor? But looking at the invertor i don't see any specific connection other than the earth out of the supply.
I also assume the characteristics of the over current devices change as well, PSC i assume will be much lower than that of say a mains fed system possibly impacting disconnection times. Also what standard do invertors have to comply to so that they supply a stable voltage / current to avoid extended tripping times if system is overloaded?
As you can see some gaps in my understanding around testing, earthing and overload protection.
Thanks in advance
John
I have a UK customer that has an agricultural building that will have a Diesel TPN generator supplying a corn dryer electrical installation.
He also wants a solar array (2kw) off grid battery backed system to supply local lights, small power, trickle charge the generator batteries (from standard 23vAC battery charger) as well as supply an intruder alarm and possible cameras.
The Invertor and array will sit on and in a metal container, outside the main building.
There will be no AC electrical connection between the Diesel and the PV, and there will be an interlock that will isolate the PV supplied battery charger from eth Diesel batteries when eth Diesel is running and charging its own batteries.
IEE, is very light on PV earthing and electrical arrangements. I have done some digging and i can see that there is an SPD risk assessment requirement, but seemingly as long as Lcrit is less than 115m I don't need anything which i think is odd.
Am looking for some install guidence if any available please?
I assume earthing is a buried electrode, with marshalling between the generator and metal services, building fabric etc. Sizing based on prospective fault current form eth invertor? But looking at the invertor i don't see any specific connection other than the earth out of the supply.
I also assume the characteristics of the over current devices change as well, PSC i assume will be much lower than that of say a mains fed system possibly impacting disconnection times. Also what standard do invertors have to comply to so that they supply a stable voltage / current to avoid extended tripping times if system is overloaded?
As you can see some gaps in my understanding around testing, earthing and overload protection.
Thanks in advance
John
I have taken a cursory look, but i think all of the above is covered. Will let you know - may be helpful for others.
