Not having a good weekend!!

[SRE]

Just gone to commission 8 Sanyo HIT 240's with a Sunnyboy 1700. There's dc power to the inverter and power from the consumer unit to the inverter but nothing in between, the display etc hasn't lit up and there's nothing being generated. We've retraced the cables and they all seem ok - any idea what we've done wrong??

 

[SolarCity]

Have you checked inside the inverter to see if you have power inside?

 

[Mark.W]

Have you installed the black DC isolator on the bottom of the Inverter?

 

[mmccx]

Have you checked polarity of the dc cables?

 

[SRE]

Yes we've tested inside the inverter and there's power inside and no the dc isolator is above about 300mm higher and slightly to the left of the inverter.

 

[SRE]

Haven't checked the polarity - had assumed that as the dc power was going through it was ok. Will check it tomorrow.

 

[mmccx]

There is also an integrated dc isolator in the sunny boy. It plugs in where the string cables plug in if you don't plug it in the inverter will not work. Technically you don't need a separate dc isolator with sunny boys because of their integrated dc isolator switches

 

[mmccx]

Don't assume always check! Even if you have labelled the strin cables check using a test meter to confirm as when you connect the string cables to the modules the negative end of the string will have a positive mc4 connector so it can plug into the negative connector on the module

 

[SRE]

Don't assume always check! Even if you have labelled the strin cables check using a test meter to confirm as when you connect the string cables to the modules the negative end of the string will have a positive mc4 connector so it can plug into the negative connector on the module

Sorry, what I meant to say was the polarity was checked when it was installed and there was a light on the inverter when we left it but nothing now. The polarity wasn't checked again today when we went to look at it. Will check the inetgrated isolator too.

 

[mmccx]

When was the light on the inverter? Did the display say anything?

 

[SRE]

The orange light was on but no-one was in!

 

[Mark.W]

What time did you try and fire it up was it maybe too dark to fire up! What was Voc and what is the MPP tracking range of the inverter?!

 

[SRE]

The first time it was getting quite late so we thought that was why nothing was happening and in the SMA instructions it's one of the options - ie yellow light continuous not enough to generate but yesterday when we went back to check it the sun was shining and there was nothing at all on the display - no lights, display nothing and nothing had been generated in the 2 weeks since we'd been at the house. The string voc was 316v when it was first tested but it was getting dark. Not sure about MPP will have to check.

 

[Markc]

There is also an integrated dc isolator in the sunny boy. It plugs in where the string cables plug in if you don't plug it in the inverter will not work. Technically you don't need a separate dc isolator with sunny boys because of their integrated dc isolator switches

You need to check the prongs on this as they can become damaged.

Also check the polarity at the SMA supplied AC plug. They are so small it is easy to make a mistake here. Yellow constantly on means disturbance. SMA don't help much here! What and where is disturbance?

 

[mmccx]

+1 for checking the ac plug! On the smaller sma's it's neutral in terminal 1 line in terminal 2 and earth in the earth terminal I beleive

 

[edexlab]

+1 for checking the ac plug! On the smaller sma's it's neutral in terminal 1 line in terminal 2 and earth in the earth terminal I beleive

Its a shame they don't use the same AC plug as the larger inverters , much more clearly identified, on the smaller ones I always have to double check

 

[edexlab]

Also its not a bad idea to check AC voltage and watch it for a while see if it varies, I had a job a few years ago (non pv) and the voltage was all over the place the bloke was complaining of shocks from his sink ,when checked it was fine ,no volts but kept testers on it for a while and it registered below 175v and up to 280v turned out there was a problem with transformer (TT)
its possible that this could be happening and its too unstable for the inverter , but check everything again

 

[mmccx]

With the above scenario I believe the inverter would turn on but shOw the appropriate error code. Would still be worth a check tho

 

[SRE]

DC polarity !!!!! Problem solved and thanks very, very much to everyone who has helped. We've now got a great troubleshooting guide for when we're onsite.

 

[Markc]

DC polarity !!!!! Problem solved and thanks very, very much to everyone who has helped. We've now got a great troubleshooting guide for when we're onsite.

Glad to got it going.