Cable Size

[newman]

Napit also guarantee there scheme members work

Thats good to know.........

 

[Manator]

Either i have had too much red or your calculator needs new batteries :Salute

I based my calcs on the original 150m run

 

[newman]

I dont understand ?How long is the AC Run from the Inverter to the DNO (Thats the electric boards) supply meter / incoming supply

How long is there dc run or did they do that correctly ?

AC run at the moment (origanal cable, goes supply meter ,farm shop ,greenhouse, barn which locates the PV system)is 150m long. New cable will go from PV system direct to supply meter 70m long

Not checked the DC side yet but I think its 4 runs of 4mm single core cable over about 18 meters(I hope this sounds right)

Did they limit the 4000TL inverter to 3680 Watts for the G83 submission ?

No idea, is there any way of checking the Inverter for limit

---------- Post Auto-Merged at 21:45 ---------- Previous post was made at 21:15 ----------

View Post

I dont understand ?

How long is the AC Run from the Inverter to the DNO (Thats the electric boards) supply meter / incoming supply

AC run at the moment (origanal cable, goes supply meter ,farm shop ,greenhouse, barn which locates the PV system)is 150m long. New cable will go from PV system direct to supply meter 70m long

Not checked the DC side yet but I think its 4 runs of 4mm single core cable over about 18 meters(I hope this sounds right)

 

[sparkytim]

So to limit the Volt drop to1 % (2.3 Volts) on a run of 70 mtrs at 16 Amps you will require a 25mm Cable

As Canoe stated

 

[newman]

This is the responce from the instlation guy today

I would like to respond to your on-going problem of your inverter

 

[steptoe]

he is talking rubbish,

%volt drop is from source.

threaten him with REAL and/or his scheme provider.

actually, don't threaten him, report him.

 

[newman]

he is talking rubbish,%volt drop is from source.

threaten him with REAL and/or his scheme provider.

actually, don't threaten him, report him.

Is there any way I can prove this

 

[steptoe]

yep, sorry, but right now Im watching the bike racing so cant be bothered going looking up the regs,

if no-one else gets you quote numbers I'll have a look later/tomorrow for you.

 

[newman]

yep, sorry, but right now Im watching the bike racing so cant be bothered going looking up the regs,if no-one else gets you quote numbers I'll have a look later/tomorrow for you.

Thanks

 

[dbicket]

Hi Newman, you describe the inverter to trip out? Does this trip a mcb or does the inverter shut down and the mains supply stay on? If the inverter shuts down it will display an error code which will let the installer diagnose the fault. The next time it shuts down check the display on the inverter and post on the forum what the code is. I agree that the cable Is not the correct size but this might not be the reason for it tripping. The incoming voltage may be to high or low it also might be fault coming from the array the list is vast so thus why the error code would be handy.

I would have also expected the installer to have checked this first ( has he). Did he connect a laptop or other communication device to the inverter to view the fault history.

In reply to tweaking the inverter .

The installer MUST get authorisation from the DNO before changing any of the grid parameters in the inverter so if he has, or is going to make sure this has been done!!

Ive had a few inverters tripping out due to high voltage from the DNO in off peak times seeing voltages from 253 and above!

Has the installer checked the incoming. Voltage??

I've only ever had to change the parameters of one inverter I've installed going through the correct routes of seeking permission from DNO and obtaining my own grid guard code.( but this process can take a long time)

Although the cable is undersized this maybe not be the issue for your install tripping. I would recommend you get this changed but there maybe another underlying fault here on your system.

Hope this helps sorry if I've missed anything from previous posts

DB..

 

[Jono Pashley]

This is the responce from the instlation guy todayI would like to respond to your on-going problem of your inverter

 

[ProDave]

Hi Newman, you describe the inverter to trip out? Does this trip a mcb or does the inverter shut down and the mains supply stay on? If the inverter shuts down it will display an error code which will let the installer diagnose the fault. The next time it shuts down check the display on the inverter and post on the forum what the code is. I agree that the cable Is not the correct size but this might not be the reason for it tripping. The incoming voltage may be to high or low it also might be fault coming from the array the list is vast so thus why the error code would be handy.

I think this is the crux of the matter, WHY is the inverter tripping. Until that's known, a solution won't be found.

So what is the maximum voltage trip? is it set by default at 253V?

You have established the volt rise due to the length of the cable is in the order of 6.4V, so if your supply was like mine, a virtually constant 246V, then that level of volt rise could trip the inverter if the limit is indeed 253V

You have established the cable volt drop does not comply, but without knowing what is tripping the inverter, that may or may not be the problem. It would be a great shame to go to all the bother of replacing the cable to get the volt drop within limits, just to find it doesn't cure the tripping because it's due to some other reason.

 

[kme]

We have had a number of problems with Sunnyboy inverters on TT installs - iirc from what was repeated to me; the fault description was "earth too high", or something similar (not MY installs, but within the company we were fitting for.

 

[newman]

Hi Newman, you describe the inverter to trip out? Does this trip a mcb or does the inverter shut down and the mains supply stay on? If the inverter shuts down it will display an error code which will let the installer diagnose the fault. The next time it shuts down check the display on the inverter and post on the forum what the code is. I agree that the cable Is not the correct size but this might not be the reason for it tripping. The incoming voltage may be to high or low it also might be fault coming from the array the list is vast so thus why the error code would be handy. I would have also expected the installer to have checked this first ( has he). Did he connect a laptop or other communication device

to the inverter to view the fault history.

In reply to tweaking the inverter .

The installer MUST get authorisation from the DNO before changing any of the grid parameters in the inverter so if he has, or is going to make sure this has been done!!

Ive had a few inverters tripping out due to high voltage from the DNO in off peak times seeing voltages from 253 and above!

Has the installer checked the incoming. Voltage??

I've only ever had to change the parameters of one inverter I've installed going through the correct routes of seeking permission from DNO and obtaining my own grid guard code.( but this process can take a long time)

Although the cable is undersized this maybe not be the issue for your install tripping. I would recommend you get this changed but there maybe another underlying fault here on your system.

Hope this helps sorry if I've missed anything from previous posts

DB..

Hi the inverter shutts down for a few mins then trys to reconnect ,only happends on a sunny day, the error code on sunny explorer is Grid Fault 1, the mains supply stays on. It does say on the inverter that the incoming voltage to high(I think} I am at the moment getting the DNO to suply me with a moniter for 14 days to chece the incoming voltage

I can understand where you are coming from,but will not the inverter assume the correct cable will have been fitted in the first place, so, say grid voltage too high

---------- Post Auto-Merged at 15:16 ---------- Previous post was made at 15:08 ----------

I think this is the crux of the matter, WHY is the inverter tripping. Until that's known, a solution won't be found.So what is the maximum voltage trip? is it set by default at 253V?

You have established the volt rise due to the length of the cable is in the order of 6.4V, so if your supply was like mine, a virtually constant 246V, then that level of volt rise could trip the inverter if the limit is indeed 253V

You have established the cable volt drop does not comply, but without knowing what is tripping the inverter, that may or may not be the problem. It would be a great shame to go to all the bother of replacing the cable to get the volt drop within limits, just to find it doesn't cure the tripping because it's due to some other reason.

Hi are you saying if I find another reason for the inverter triping ,say inverter is set at the wrong settings for a high DNO voltage supply,then I have no need to replace the cable.

 

[steptoe]

has this guy even set the inverter to G83 I wonder.....?

I have been to a few that havent been changed from factory settings, it seems sunnyboys are particularly fussy about this.

 

[newman]

I have a few questions

On a 150 meter I have been told I need 50mm cable for less than 1% VD, why do I need 1% VD,

Whats the point of 50mm cable when the incoming suply to the house CU is only 16mm

 

[ProDave]

Hi are you saying if I find another reason for the inverter triping ,say inverter is set at the wrong settings for a high DNO voltage supply,then I have no need to replace the cable.

What's the make / model of the inverter?

Does it display the grid side ac voltage and current, if so what voltage is it reading? does that voltage increase much on a sunny day when it's generating near to full power?

Have you seen anything on the display to say G83 or anything else?

I assume the messages on screen are in English?

 

[newman]

What's the make / model of the inverter?Does it display the grid side ac voltage and current, if so what voltage is it reading? It reads at the moment(dull day) 31A 243v-247v does that voltage increase much on a sunny day when it's generating near to full power? Yes I have seen it at 263v but inverter gets to full power, 3kw max then cuts out

Have you seen anything on the display to say G83 or anything else? Have been through it with SMA on sunny explora and checked the inverter settings ,it said G83/1

I assume the messages on screen are in English?

Yes

 

[binky]

Have just checked system on PV-sol, which would suggest that 16 250w Suntechs won't work with the SMA 4000TL inverter, in that the system will output 16A for an inverter capable of taking 15.3A (assuming 2 strings of 8 panels)This might explain why inveretr keeps tripping out on sunny days - it's protecting itself from being overpowered. Could you do me a favour and double check exact panel and inverter models to make sure I have modelled the right stuff.

 

[newman]

Modle of inverter Sunny Boy 4000TL