Insulating Timber Garage

[Joeboy]

Fence finally finished..
All those wee jobs getting ticked off

Very nice indeed!

[AGT]

900x1800 plasterboard- easier for manual handling
100mm generic Insulation board and 2 rolls pure/treated sheep wool ready for Monday- insulating dormer and dormer cheeks..

[AGT]

Not the nicest job removing lath and plaster, but done, bagged up and outside ready for dump.
All cleared up and ready for insulation tomorrow

[AGT]

Just had letter from SP.

Fee for design work £250
Export 9.7kVA

Having never dabbled in export is this figure good?

[Stinsy]

Just had letter from SP.

Fee for design work £250
Export 9.7kVA

Having never dabbled in export is this figure good?

For single phase 9.7kVA is brill!

16A is guaranteed, 20A would normally be authorised, 40A is a big win! I guess you’re pretty close to a big transformer?

Have you measured your grid voltage?

[AGT]

Ah result then!

Not measured recently, never had an issue with voltage they did stipulate the max voltage rise of 2.5% at the Point of connection
Maybe 50m diagonally to a transformer on the other side of the road to the cutout at my house.

Appreciate the info!

[Stinsy]

Ah result then!

Not measured recently, never had an issue with voltage they did stipulate the max voltage rise of 2.5% at the Point of connection
Maybe 50m diagonally to a transformer on the other side of the road to the cutout at my house.

Appreciate the info!

My question about grid voltage is because your inverter will be programmed to cut out if the voltage gets too high. The more power your inverter exports the higher the voltage will get. Sometimes the grid is over-voltage without you exporting anything and DNOs aren’t necessarily in a rush to fix it.

It is definitely worth ensuring the inverter is as close to your CU as possible and oversizing the cable. However voltage drop calculations are simple enough…

[AGT]

It’s 20m away fed from 10mm2 Swa.

[Stinsy]

It’s 20m away fed from 10mm2 Swa.

Youl'll be looking at c. 3.7V voltage-drop on that SWA. This means when your inverter is exporting at 9.7kW the Voltage at the inverter end will be 3.7V higher than the CU end. So if your grid voltage is borderline but within spec, your inverter will still trip it's over-Voltage protection.

Obviously, there will always be a voltage-drop on any cable. 16mm² SWA would be 2.4V for example and a shorter cable would be proportionally lower.

Some inverters trip off in an overvoltage condition and try again 5-mins later, others dynamically manage their output and throttle to stay within spec.

It is worth checking your grid voltage to see if you have a problem. I have a bazillion devices that record voltage! Eg this is what my hot water tap sees: