cable size selection

[jason121]

Would the inverter manufactures allow this. Steca for example require a letter from the DNO before they issue the pass codes

 

[Worcester]

Would the inverter manufactures allow this. Steca for example require a letter from the DNO before they issue the pass codes

Depends upon the make and model of inverter, and your relationship with the manufacturer - i.e. are you a 'trusted' installer.

 

[jason121]

You cannot base your installation on that line of thought, New inverters are coming on the market everyday, some inverters work well in different situations then others. Going to speak to the guy who does our G59 tests

 

[Gavin A]

Would the inverter manufactures allow this. Steca for example require a letter from the DNO before they issue the pass codes

it's nowt to do with them is it, as long as the operating voltage is within their operating range. You've installed a G59 relay to fulfil that requirement, and it's you that is signing the DNO papers to verify that the system meets the G59 requirements, not the inverter manufacturer.

if the inverter manufacturer won't play ball, use one from a manufacturer that allows the installers to make these adjustments.

 

[jason121]

Most inverters require pass codes to alter there settings

 

[Gavin A]

either use one like SMA who give you a single code to use on any of their inverters, or get the necessary code by explaining that you're using a G59 relay.

this isn't some sort of trick, it's entirely in line with all the relevant regulations.

 

[jason121]

Will give this idea a go. Any idea what the max safe voltage is for sma inverters

 

[infinity]

Just to clarify, when doing volt drop calcs, from the BGB do you use the X R Or Z value for mV/A/M?
Obviously there is a big difference between the Z and X (resistive) figures

 

[jason121]

I would calculate using z

 

[infinity]

That's what I used. But the tech guy from power one said to use the R value as it's purely resistive thus selecting 50mm csa which does doesn't seen right.

Napit tech, said to only allow 75% of current in calcs as it will rarely be full power, which also doesn't seem right as it would trip out on sunny days!

 

[Gavin A]

That's what I used. But the tech guy from power one said to use the R value as it's purely resistive thus selecting 50mm csa which does doesn't seen right.

Napit tech, said to only allow 75% of current in calcs as it will rarely be full power, which also doesn't seem right as it would trip out on sunny days!

entirely depends how you've loaded the inverter, if you've been sensible and run the panels at something like 120% of inverter rating, then disregard what napit just said, the entire point of these calcs is to prevent excessive volt rise at peak generation.