New Solax Panels and Inverter breaker tripping all time

[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.

 

[whinmoor]

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).

It might be worth the installer removing that 6A MCB in this case to eliminate that from the equation and to reduce the likelihood of someone deciding to connect something in there in the future. It might fetch £3 on eBay to contribute towards his fuel bill for running around trying to sort out this problem

 

[Worcester]

What about C rated MCB ??

That would have been my thought, or even a type D if the Zs is low enough.

 

[AWAKEFIELD720]

Chhers all, il get them to re,ove the spare oneand change the mcb for 20amp type c, spoke to solax today and they are going to talk go the electrician friday whilst here to do a few checks wheter the inverster is faulty itself, il let you kno outcome.