Solax inveter tripping MCB

[tomcoleman]

i currently charge my Solax batteries at night time on the cheaper tarrif.

almost every night the MCB breaker tripps thats connected to the solar.

I can see from the logs the batteries start sucking power from the grid and ramp up over the period of a hour and get upto 7.1kw charging at which point the MCB tripps and charging stops.

The batteries/inverter/breaker it is connected to is a Live Electrical CA132B 32 Amp Single Pole Type B 6kA 230V Miniature Circuit Breaker MCB (i see this is rated at 32amp and 6000w)

Now i presume becuase the sucking power from the grid to charge the batteries its bursting to over 7kw this causes the fuse to "trip"? ?

i was thinking of replacing the MCB with the same size AMP but rated at 10kA

Schneider Electric SE10B132 MCB SP B 32A 10kA


or upgrade the cable from 4mm to 8-10mm with a 40/50AMP


Schneider Electric SE10B140 MCB SP B 40A 10kA
Schneider Electric SE10B150 MCB SP B 50A 10kA

 

[Murdoch]

Dare I ask who did the installation?

 

[tomcoleman]

Dare I ask who did the installation?

sure it was a company called "project Solar"

however they used 3rd party installers.

I'm only noticing now that A) cable size seems under-rated and B) fuse and componets used arent according to solax manual.

 

[tomcoleman]

My unit is the X1-Hybrid-7.5-D which according to the manual should be 8-10mm and 50A

 

[Murdoch]

sure it was a company called "project Solar"

however they used 3rd party installers.

I'm only noticing now that A) cable size seems under-rated and B) fuse and componets used arent according to solax manual.

Then you should be talking to the company who took your money ........

 

[tomcoleman]

Then you should be talking to the company who took your money ........

@Murdoch i'am but they are VERY slow to respond almost un-intrested as it was installed about 8 months ago.

I'm happy to source my own sparky but want to get the components correct and not call him back mutiple times ending up costing me more. Ive almost written off projectsolar helping at this point.

Currently the 32A breaker is rated at 6kA

If i switch/upgrade this to 32A @ 10kA

I presume this will do the trick?

 

[Murdoch]

Could you post a photo of the consumer unit its connected to?

 

[tomcoleman]

Could you post a photo of the consumer unit its connected to?

here is a photo of the mini solar consumer box.

the blue 32AMP one is the one that trips (only at night) when i charge the batteries from the grid.

I can see from the logs it goes to around 7000-8000w pulling from the grid then trips.

Presume becuase the fuse is only 6kA its over its limit.



let me see if i have a photo of the main consumer box.

The L+N are fed from a connector block which is fed from the 100AMP cable that comes from the street

 

[Murdoch]

here is a photo of the mini solar consumer box.

the blue 32AMP one is the one that trips (only at night) when i charge the batteries from the grid.

I can see from the logs it goes to around 7000-8000w pulling from the grid then trips.

Presume becuase the fuse is only 6kA its over its limit.

View attachment 15091

let me see if i have a photo of the main consumer box.

The L+N are fed from a connector block which is fed from the 100AMP cable that comes from the street

Wow thats RAF

What paper work / certificates were you given by the installer?

 

[tomcoleman]

Wow thats RAF

What paper work / certificates were you given by the installer?

that photo was with the cover off so you can see the wires etc.

I got a eletrical certificate that it was all tested and passed those tests.

My argument with them is that the Solax manual says 8-10mm cable and breaker should be 50AMP

installed was 4mm cable with a 32A breaker.

Do you have any knowledge of my question above around changing the 32A MCB to a 32A 10kA MCB which should fix the tripping issue?

 

[denmancentral]

kA rating is not relevant to the tripping, that's the maximum short circuit current the MCB can handle.

8000W is about 33A so although the MCB shouldn't immediately trip unless the current is much higher, it is undersized.

I would ask the electrician to run the correct diameter cable and supply a new 50A MCB. They will want to know the inverter specs and cable length plus how the cable is run (clipped direct, in insulation etc).

 

[tomcoleman]

kA rating is not relevant to the tripping, that's the maximum short circuit current the MCB can handle.

I would ask the electrician to run the correct diameter cable and supply a new 50A MCB from a decent brand.

thanks for the input here

so you think the batteries are pulling more then 32A?

The batts themselfs say they have a max charge/discharge rate of 30A but maybe the breaker is just utter crap.

its like £1.50 to buy it.

I have the new breakers coming.

I'm going to get the cable changed to the proper value anyway 8-10mm!!

 

[denmancentral]

if you have a measurement showing 8000W then it's likely above 30A, yes. Divide power by voltage to get approx current.

 

[tomcoleman]

if you have a measurement showing 8000W then it's likely above 30A, yes. Divide power by voltage to get approx current.

@denmancentral thanks so 8000w would be around 33AMP
7000w 29.1AMP

Maybe its just on the limit and the breaker is crap.

Let me switch it over (in the meantime) and i'll get the sparky booked in to upgrade the cable + breaker for future appointment

will keep you all posted.!!

 

[johnb2713]

@denmancentral thanks so 8000w would be around 33AMP
7000w 29.1AMP

Maybe its just on the limit and the breaker is crap.

Let me switch it over (in the meantime) and i'll get the sparky booked in to upgrade the cable + breaker for future appointment

will keep you all posted.!!

In the meantime, reduce the max charge current from the inverter?

 

[tomcoleman]

In the meantime, reduce the max charge current from the inverter?

John i tried that last night by changing this setting from 30A to 25A i have now reduced it to 10A

I think its the right setting to change for solax?

Batery Max Charge Current. = 10A
Battery Max Discharge Current = 30A

 

[johnb2713]

John i tried that last night by changing this setting from 30A to 25A i have now reduced it to 10A

I think its the right setting to change for solax?

Batery Max Charge Current. = 10A
Battery Max Discharge Current = 30A

View attachment 15092

That would seem to be the one.

 

[tomcoleman]

That would seem to be the one.

the MCB migh be dead because even at 25A it was tripping.

i'l see what 10A does.

New MCB's on route also.

 

[Murdoch]

I love the change parts and see approach.

You should complain in writing to the company who took your money and the minute you change anything they will refuse to come again

 

[tomcoleman]

I love the change parts and see approach.

You should complain in writing to the company who took your money and the minute you change anything they will refuse to come again

i kinda lost faith ages ago when i was emailing them on another matter.

they are too busy looking for the next install.

better to wipe my mouth, spend the £100-400 on upgrade and move on