New Solax Panels and Inverter breaker tripping all time

[AWAKEFIELD720]

I recently got the system installed and was ok for a few weeks then came home to a fault, installers said due to thunder storms which i accepted as ok. Then week later same again with no storms. They have since put the breaker and rcd in a seperate box and said would be ok. Then same again tripping on breaker.
Engineer came out again and fitted a new breaker which was to cope with my panels performing well they said. Since then tripped 4 consecutive days. I am not electrically experienced and hence my reason im here to make sure i get someanswers. I have attached pictures of Inverted, wiring and the rcd box

Thanks in advance

 

[Paul.M]

Thread approved for posting. Please give help and advice like you always do gents

 

[Leesparkykent]

Is it the RCCB that's tripping?

 

[davesparks]

There is obviously a fault in the system, get the installers back to repair the fault.
Don't just keep in closing the breaker everytime it trips, without knowing what the fault is it may well damage the breaker

 

[AWAKEFIELD720]

There is obviously a fault in the system, get the installers back to repair the fault.
Don't just keep in closing the breaker everytime it trips, without knowing what the fault is it may well damage the breaker

They have beeh back 3 times, added the seperate box with the breaker in it and upped the rating of it to 20amp , see in the closeup pic with the small box its the breaker in middle with solar panel wrote on label above, thanks for reply

 

[AWAKEFIELD720]

Picture 2 with pv label above keeps tripping :dizzy2:

 

[davesparks]

They have beeh back 3 times, added the seperate box with the breaker in it and upped the rating of it to 20amp , see in the closeup pic with the small box its the breaker in middle with solar panel wrote on label above, thanks for reply

Oh dear, I think they might be a bit short on actual understanding of what is happening.
I don't know enough about be PV to offer advice on what the fault may be, but I do know that MCBs don't trip for no reason. Something is causing an excess of current to flow, either a fault or I guess maybe a design flaw in their installation.
They need to come back and find the fault, I would suggest writing to them requesting that they attend to find and repair the fault or they pay for someone who knows what they are doing to carry this out. Possibly advise them that you will be contacting trading standards or their MCS registration body

 

[SibertSolar]

Not "obviously" a fault as such, although I agree with the advice davesparks. A 30mA trip limit with TL inverter, possible insulation resistance issues on DC strings, local loads sharing RCD (maybe) and earthing arrangement (if any) of the array frame, can easily nuisance trip.....

 

[SibertSolar]

Ah, just re-read and OP says it was the MCB tripping, not the RCD....apologies, ignore above

 

[Leesparkykent]

Not "obviously" a fault as such, although I agree with the advice davesparks. A 30mA trip limit with TL inverter, possible insulation resistance issues on DC strings, local loads sharing RCD (maybe) and earthing arrangement (if any) of the array frame, can easily nuisance trip.....

Its the mcb that is tripping not the RCD.

edit: posted same time as SibertSolar

 

[davesparks]

Not "obviously" a fault as such, although I agree with the advice davesparks. A 30mA trip limit with TL inverter, possible insulation resistance issues on DC strings, local loads sharing RCD (maybe) and earthing arrangement (if any) of the array frame, can easily nuisance trip.....

Nuisance tripping is still a fault.
The OP has stated that the MCB is operating, not the RCD, therefore there must be an overcurrent occurring

 

[infinity]

We hAve installed one of these with the same problem! Turns out it required a 20A MCB instead of the usual 16, no real reason why but it's in the manual for the installation.
It solved the problem

 

[Leesparkykent]

We hAve installed one of these with the same problem! Turns out it required a 20A MCB instead of the usual 16, no real reason why but it's in the manual for the installation.
It solved the problem

Its on a 20amp type B

 

[AWAKEFIELD720]

Thats whatvthey did last time put a 20A mcb in, made it even worse, was 16 originally. They are coming back friday to replace the entire Inverter:uhoh2:. Good advice ontelling them about contacting mcs though as they seem to be guessing as much as me

 

[Gavin A]

bit harsh to be contacting MCS / their body at this stage in proceedings.

tbh it could simply be that the inverter isn't restricted to 16A as it should be (unless you have permission to generate more than 16A).

Solar's different to almost every other load other than maybe storage heaters in that it can operate at full capacity for maybe 6-8 hours at a time at the peak of summer, so it ends up on parts of the tripping time curve for MCBs that are almost never reached, so MCB's ratings shouldn't be too close to the max rating of the inverter or they will risk tripping at the peak of summer.

 

[davesparks]

bit harsh to be contacting MCS / their body at this stage in proceedings.

tbh it could simply be that the inverter isn't restricted to 16A as it should be (unless you have permission to generate more than 16A).

Solar's different to almost every other load other than maybe storage heaters in that it can operate at full capacity for maybe 6-8 hours at a time at the peak of summer, so it ends up on parts of the tripping time curve for MCBs that are almost never reached, so MCB's ratings shouldn't be too close to the max rating of the inverter or they will risk tripping at the peak of summer.

Not harsh at all, they've had 3 opportunities to identify and rectify the fault and have so far made what appear to be random guesses. 1- blame it on thunderstorm 2- move the mcb out of the board and in to a seperate enclosure 3- uprate the mcb. This sounds like sheer incompetence to me, especially if the person responsible is an engineer as stated above.

Solar is not a load at all it is a source of energy.

 

[infinity]

It could well be classed as a load in terms of how it works, just in reverse. The MCB can't detect polarity.
Gavin's knowledge in all things solar will far exceed yours.
He's correct with everything he says. There's no other domestic load designed to run at full load like an inverter can/ will.
Also, it seems the 'engineer' has taken steps to correct the fault. Sometimes it can be as simple as a faulty inverter, we can assume he has tested the circuit. Usually very simple being s radial, so has eliminated any other components at the same time.

 

[AWAKEFIELD720]

bit harsh to be contacting MCS / their body at this stage in proceedings.

tbh it could simply be that the inverter isn't restricted to 16A as it should be (unless you have permission to generate more than 16A).

Solar's different to almost every other load other than maybe storage heaters in that it can operate at full capacity for maybe 6-8 hours at a time at the peak of summer, so it ends up on parts of the tripping time curve for MCBs that are almost never reached, so MCB's ratings shouldn't be too close to the max rating of the inverter or they will risk tripping at the peak of summer.

Im not going to yet, just in my back pocket if goes ---- up. Their customer service has been terrible though to much to explain. It has been generating loads they said highest they have seen on a 4kw system?. Shouldnt the 20A breaker has worked though ?what do you recomend

 

[AWAKEFIELD720]

Spot on davesparks .. jst how i feel , i shouldnt be having to raise this question they are the competant installers and electricians not me

 

[AWAKEFIELD720]

Could they try a higher rated mcb higher than 20A then to avoid new inverter install ?

 

[davesparks]

It could well be classed as a load in terms of how it works, just in reverse. The MCB can't detect polarity.

It cannot be classed as a load, it is a source of energy!
A load is a component or part of a electrical circuit which consumes electrical power, a source of energy is that part of a circuit which produces electrical power.
(Technically it is the conversion of energy from one form to another rather than consuming/producing power, but that is irrelevant to the point)

I'm sure he does know more about solar than me, but the point still remains that a specialist company has installed a system which does not function as intended and have repeatedly failed to rectify the situation.

 

[matthunt]

do you happen to know what your voltage is at home?

 

[davesparks]

Solar's different to almost every other load other than maybe storage heaters in that it can operate at full capacity for maybe 6-8 hours at a time at the peak of summer, so it ends up on parts of the tripping time curve for MCBs that are almost never reached, so MCB's ratings shouldn't be too close to the max rating of the inverter or they will risk tripping at the peak of summer.

This makes no sense, an mcb is rated to carry its full load current indefinately. The tripping curve will always be above it's rated current for its rated operating environment (ambient temp, altitude, humidity).
Do you have a graph of the output current of one of these inverters outputting at maximum?

 

[AWAKEFIELD720]

I can acess graphy through wifi on inverter , il check what it says.... how will i know the voltage in my home .. excuse my lack of knowledge on this.. im a hydraulics engineer not this electrc black magic :smiley2:

 

[matthunt]

do you happen to know what your voltage is at home?

reason I ask is that the inverter is close to your consumer unit, now if the installer has set the inverter to 262v (which is wrong) and a common misconception with some installers due to a high residential voltage then you could get higher currents generated.

 

[davesparks]

I can acess graphy through wifi on inverter , il check what it says.... how will i know the voltage in my home .. excuse my lack of knowledge on this.. im a hydraulics engineer not this electrc black magic :smiley2:

My comment about a graph was intended as a reply to the Gavin A
But if you can access a graph of current output in the hours leading up to and the point at which it trips that may be helpful in working out what's wrong.
Without measuring it you won't be able to tell your supply voltage, unless the inverter has the ability to tell you this?

 

[matthunt]

I can acess graphy through wifi on inverter , il check what it says.... how will i know the voltage in my home .. excuse my lack of knowledge on this.. im a hydraulics engineer not this electrc black magic :smiley2:

Yes you can check the output voltage and current though the wifi log

 

[AWAKEFIELD720]

Output current is always peaking at below 15A, Voltage is 248.4v , never gome above 15A in graphs since install

 

[davesparks]

Output current is always peaking at below 15A, Voltage is 248.4v , never gome above 15A in graphs since install

Unfortunately we don't know how those current readings are taken, or what they actually represent. They may be averaged values over a sampling period, wheras a maximum value from each sampling period may tell a different story.

 

[AWAKEFIELD720]

Il post the graphs of output voltage n output current tmorro you will make more sense than me

 

[whinmoor]

A few basic questions:

1. How many panels? What brand and wattage?

2. What model of Solax? - Check nameplate on side of inverter. Is it the "SL-TL3600" or "SL-TL3600T" or something different?

3. Has the installer checked the inverter is set up for UK usage? If not, suggest it.

4. Has the installer tried a different mini consumer unit? Maybe a different brand might work. Suggest it.

5. If it's a TL3600 or TL3600T, has the installer used 4mm AC cable and a 25A MCB as recommended in the installation instructions? If not, suggest it.



6. Has the installer offered to try a different brand of inverter? If not, suggest it.

 

[Worcester]

@whinmoor

25A, that's a very unusual recommendation, any idea why that high?
Would tend to indicate that it's not G83 compliant.

 

[davesparks]

@whinmoor

25A, that's a very unusual recommendation, any idea why that high?
Would tend to indicate that it's not G83 compliant.

Looking at the snapshot of the instructions which has been posted if say it wasn't written by someone with a good knowledge of UK wiring practices or regulations!

 

[whinmoor]

@whinmoor

25A, that's a very unusual recommendation, any idea why that high?
Would tend to indicate that it's not G83 compliant.

I don't know. Suggests to me they are worried about getting spikes well over 3.68kW and can't control or guarantee the limiting function in certain conditions. Could be that they are concerned when installers fit 5kW (or even more) of panels and use the inverter to cap at G83 levels.

Could be that it's a typo but I doubt it. I prefer the explanation above.

Probably a question for their technical team rather than a humble installer.

 

[AWAKEFIELD720]

A few basic questions:

1. How many panels? What brand and wattage?

2. What model of Solax? - Check nameplate on side of inverter. Is it the "SL-TL3600" or "SL-TL3600T" or something different?

3. Has the installer checked the inverter is set up for UK usage? If not, suggest it.

4. Has the installer tried a different mini consumer unit? Maybe a different brand might work. Suggest it.

5. If it's a TL3600 or TL3600T, has the installer used 4mm AC cable and a 25A MCB as recommended in the installation instructions? If not, suggest it.

View attachment 29639

6. Has the installer offered to try a different brand of inverter? If not, suggest it.

Hi,

Number of panels - 16 - 2 x string of 8 = 4 kw system - Solax panels 250w

consumer unit ?? sorry I don't know what that is

they are using a 20A MCB that keeps tripping - Inverter model no il check at dinner time

il mention the uk usage thing thanks

 

[AWAKEFIELD720]

How do I add the graph images ? cant see how to upload image like on original post ? only enter url which I don't want to do ? want to upload thumbnail ....

 

[AWAKEFIELD720]

Hi,

Number of panels - 16 - 2 x string of 8 = 4 kw system - Solax panels 250w

consumer unit ?? sorry I don't know what that is

they are using a 20A MCB that keeps tripping - Inverter model no il check at dinner time

il mention the uk usage thing thanks

Its a TL-3600 ... should be a 25A MCB then not 16 or 20 like they have used ... can you send me the full document this is extracted from ? thanks

 

[TedM]

http://www.solaxuk.co.uk/download/SL-TL_Install_Manual.pdf

 

[AWAKEFIELD720]

Thanks, just got it from Google. really strange that the maximum current output in the graphs I have are all below 16A yet its tripping on a 20A breaker ... Im very confused

 

[jason121]

What about C rated MCB ??

 

[davesparks]

Thanks, just got it from Google. really strange that the maximum current output in the graphs I have are all below 16A yet its tripping on a 20A breaker ... Im very confused

What you won't be able to see on the graphs as they are likely to be based on average readings for the sampling period is that there may be current peaks in the output.
We either increase the size of an MCB or use different types of MCB to avoid it tripping from these current peaks.

 

[Gavin A]

This makes no sense, an mcb is rated to carry its full load current indefinately. The tripping curve will always be above it's rated current for its rated operating environment (ambient temp, altitude, humidity).
Do you have a graph of the output current of one of these inverters outputting at maximum?

experience indicates this is not always true in practice.

None of the curves I've seen run past 10000 seconds, or under 3 hours, some of our systems can be running at full capacity for 6-8 hours at a time.

And you're ignoring the impact of ambient temperature, which when these units are in an enclosed board, and running at full load on hot sunny days in summer for so long does result in the air temperature inside the board rising significantly, and I've felt an MCB after it's tripped and it must have been at 50-60 degrees C.

At 40 degrees C ambient temperature there's between a 5-10% derating, rising to 12-20% at 55 degrees.

http://www.farnell.com/datasheets/1672135.pdf

 

[Gavin A]

It cannot be classed as a load, it is a source of energy!
A load is a component or part of a electrical circuit which consumes electrical power, a source of energy is that part of a circuit which produces electrical power.
(Technically it is the conversion of energy from one form to another rather than consuming/producing power, but that is irrelevant to the point)

I'm sure he does know more about solar than me, but the point still remains that a specialist company has installed a system which does not function as intended and have repeatedly failed to rectify the situation.

ffs it's the same as a load for the purposes of what it's doing to an MCB, albeit that the power is running in the opposite direction.

Unless your contention is that the direction of flow makes a difference, then you're just willy waving about an irrelevant point that should have been entirely obvious to anyone with half a brain. Was that your contention or were you just willy waving?

 

[davesparks]

ffs it's the same as a load for the purposes of what it's doing to an MCB, albeit that the power is running in the opposite direction.

Unless your contention is that the direction of flow makes a difference, then you're just willy waving about an irrelevant point that should have been entirely obvious to anyone with half a brain. Was that your contention or were you just willy waving?

I know the direction of current flow is inconsequential to an mcb.
But a source of energy and a load are not the same thing, it is not willy waving as you put it but a fundamental point of the science of electricity. If a person claiming to be an electrician cannot get such a fundamental point right then I would seriously doubt their credibility.
When a source of energy begins to act as a load then there is serious problem likely to have some disasterous results.

 

[davesparks]

experience indicates this is not always true in practice.

None of the curves I've seen run past 10000 seconds, or under 3 hours, some of our systems can be running at full capacity for 6-8 hours at a time.

And you're ignoring the impact of ambient temperature, which when these units are in an enclosed board, and running at full load on hot sunny days in summer for so long does result in the air temperature inside the board rising significantly, and I've felt an MCB after it's tripped and it must have been at 50-60 degrees C.

At 40 degrees C ambient temperature there's between a 5-10% derating, rising to 12-20% at 55 degrees.

http://www.farnell.com/datasheets/1672135.pdf

Then the mcb has been incorrectly installed. Alternating of high and low load MCBs and leaving gaps between them to allow the dissipation of heat should be considered in the design.

 

[Gavin A]

Then the mcb has been incorrectly installed. Alternating of high and low load MCBs and leaving gaps between them to allow the dissipation of heat should be considered in the design.

don't get that option with solar PV, they're all running at peak at the same time all the time that they're running at peak.

So you need to consider this in the design by not running the MCB ratings too close to the max inverter rating... as I said in my first post, that you stated made no sense. Care to retract that statement?

 

[Gavin A]

I know the direction of current flow is inconsequential to an mcb.
But a source of energy and a load are not the same thing, it is not willy waving as you put it but a fundamental point of the science of electricity. If a person claiming to be an electrician cannot get such a fundamental point right then I would seriously doubt their credibility.
When a source of energy behind to act as a load then there is serious problem likely to have some disasterous results.

So whether it's a load or a generation source is entirely irrelevant to how it impacts on the MCB, and therefore to this thread?

In which case, what has been the point in your contributions to this thread?

 

[davesparks]

don't get that option with solar PV, they're all running at peak at the same time all the time.

So you need to consider this in the design by not running the MCB ratings too close to the max inverter rating... as I said in my first post, that you stated made no sense. Care to retract that statement?

Why don't you have that option? Install a larger board to allow for cooking space between the MCBs or use HRC fuses.

 

[Gavin A]

Why don't you have that option? Install a larger board to allow for cooking space between the MCBs or use HRC fuses.

I meant the option of running high and low loads next to each other.

Although in this case they've got an unused 6A MCB next to it, and it's still doing it (assuming this is the cause).

 

[Gavin A]

Admittedly the wording of my first post was a bit sloppy, it was 1am or something, but the gist of it was right.

Having said that, we've installed loads of these make of garage units for 16amp single phase installs and I don't remember having the MCB trip on more than maybe 2 units. The RCD proved a bit more of an issue, so we mostly stopped fitting them a couple of years back as they usually aren't needed with wiring methods used.