RCD Trips

[steve58]

Two jobs both identical with panels and invertors ect. Ie: Aurora 3.6 TL , 14 panels 235w. Both using Wylex garage boards 16amp mcb and 63a 30ma RCD 4mm T&E. One starts up and works no problem the one next door trips RCD. Done all checks and test all ok. Invertor goes through start up all ok then after about 2 mins trips RCD. Any ideas please

 

[BruceB]

TL inverters can have some leakage.

Don't the Aurora instructions recommend a 300mA rcd if you have one?

 

[Glen Powell]

Wylex are IMO the worst for nucence (sp) tripping, try a different RCD of same design probably be OK lol :S

 

[rich.250]

Earth leakage clamp meter?? Have you ramp tested Rcd to check it is functioning correctly?

 

[steve58]

Yes done a ramp test and all ok but still changed RCD just to be sure

 

[rich.250]

Have you measured leakage? Just incase there is faulty equipment??

 

[mmccx]

any tl inverter will take out 30ma rds all day long. Either scrap the rcd all together of change to 100ma at least - obviously provided installation method of cable allows or its a tt system

 

[Glen Powell]

any tl inverter will take out 30ma rds all day long. Either scrap the rcd all together of change to 100ma at least - obviously provided installation method of cable allows or its a tt system

Really? I have not noticed this, what evidence do you have? I need to ensure our installers are not doing something wrong, saying that we have not had an influx of complaints about RCD trips either which I am sure we would of had with the amount of installs carried out

 

[mmccx]

The amount of ones I have had to change in recent months! Also all manfacturers I use recommend Atleast 100ma SMa solarmax eversolar fronius etc. 30ma rcd's will generally go randomly and from experience will happen mostly on duel tl inverter setups and the larger size inverters 3.5 kwvand up although it has happened on the smaller ones.

Also never put an inverter on a shared rcd's just in case you didn't know

 

[Glen Powell]

I would not expect you to and our company has installed 30ma Type B RCDs for over 7 years and out of all the installs only had to replace about two which were on tin roofs.

Is this not just masking a problem within the houshold or the design? Why would you have residual current on a class II product ??

As a quick question how many other installers increase the RCD size to combat tripping ?

 

[mmccx]

It's the residual current from the inverters and not the modules that are the issue I believe. Tl inverters appear to have a high residual current on them particularly on startup shutdown and well whenever they seem to please. As long as the cable is installed without the need for 30ma protection the I would not use one or use are larger rated rcd otherwise IMO you are asking for nuisance tripping when installing a tl inverter

 

[Glen Powell]

Sorry, I am quite new to the forum, How is the residual current created? most inverters have an IP rating don't they? and they would be sited according to their IP rating (I assume). I am trying to get around the fact that a TL inverter would have more leakage than a transformer inverter.

Transformer inverters are the old reliable inverters however I would dispute the fact that TL inverters have more Residual Current / Inballance and in practice I would have to disagree with you.

I know as that we have only facilitated approximately 2000 installs this year, this does not make me an expert, however we have not had a problem due to undersized (as you say) RCDs

 

[mmccx]

All I can speak from is my experience and you can only speak from yours, and what I have found is that tl inverters will trip 30ma rcd's. Why for sure I cannot say but if manufacturer recommendations are anything to go by the ones we install reccomend Atleast 100ma and no less. A good example would be an SMa 4000tl.

 

[mmccx]

Also I never said anything about undersized rcd's all I said was that I find to inverters trip 30 ma

 

[Glen Powell]

If you are happy that is suitable from the manufactures and BS7671 then we are both happy