[Sir Liamalot]

I've been licking my wounds. I'd another €2.5k inverter sh1t the bed..
sigh...

Originally Posted by Buford T Justice

Remove the double pole mcb that's the input for the inverter and go direct to the RCBO instead

You can't protect against overcurrent on an inverter output. They can't supply the power...it's not like the grid where a short circuit has the ESB Network to throw at the circuit breaker.
Earth leakage is all you need. RCBO, RCD..whichever.

Originally Posted by Buford T Justice

neutral out of the inverter to the earth of the van (chassis), most likely at the output point of the RCBO above

Earth to the neutral of the generator upstream of the RCD. In this case, the inverter. The earth is connected to the van chassis but that's further downstream and tangental.
You're making a fault path that will create an imbalance on the RCD and enable it to trip if there's an issue.
Shore power will already be neutralized so make sure your inverter neutralisation point is exclusive to inverter operation ie. upstream of the changeover contactor.

Originally Posted by Buford T Justice

Earth output & body of inverter to van chassis
Earth the consumer unit to the van chassis

When you say van chassis it ought to be the earth bus. The chassis and all metalwork with a mains appliances are connected to that earth bus.

Originally Posted by Buford T Justice

What's the benefit of the delay timer?

Gauranteed break before make. It stops you creating 400v from contact arcs in places you don't want.


Quote:
Check for continuity between live and van shell & neutral and van shell too with the system unpowered. Should be neither if you're floating earth.

Originally Posted by Buford T Justice

Are you referring to the final 240 supply feeding to the sockets to check?

You checked you have mains and inverter at the outputs.
You also need to check that you don't have inverter and mains at their counterparts inputs.


ie. no mains at the inverter output upstream of the changover and no inverter at the EHU pins upstream of the contactor.

[Buford T Justice]

Originally Posted by Sir Liamalot

I've been licking my wounds. I'd another €2.5k inverter sh1t the bed..
sigh...

Ouch - I know that feeling, albeit on a much less expensive scale

Gauranteed break before make. It stops you creating 400v from contact arcs in places you don't want.

So the delay timer should be on the shore live into the changeover unit and not the coil?

Earth to the neutral of the generator upstream of the RCD. In this case, the inverter. The earth is connected to the van chassis but that's further downstream and tangental.
You're making a fault path that will create an imbalance on the RCD and enable it to trip if there's an issue.
Shore power will already be neutralized so make sure your inverter neutralisation point is exclusive to inverter operation ie. upstream of the changeover contactor.

Any concern with the fact that the neutrals from both supplies are tied together upstream of the contactor? (red circle in last diagram)?

You checked you have mains and inverter at the outputs.
You also need to check that you don't have inverter and mains at their counterparts inputs.


ie. no mains at the inverter output upstream of the changover and no inverter at the EHU pins upstream of the contactor.

I did check this already, as I know that this would be very bad, and it seems right. I've ordered those thermisters from RS, and I couldn't justify spending 4 quid online so I added a tester to it as well which can help.

I found an old 500w inverter in the shed that I'll be able to use to test this system fully. Just wanted to have a list of the things to do really.

[Sir Liamalot]

Originally Posted by Buford T Justice

Ouch - I know that feeling, albeit on a much less expensive scale

I paid a lot less for it. There's a replacement on the way.

Dunno what happened I'm chatting to the manufacturer. It died while synchronising & backfeeding the grid...certain death if it misses a beat at 50hz by 90° phase angle.

feckin yolk ate my hydronic system...

Originally Posted by Buford T Justice

So the delay timer should be on the shore live into the changeover unit and not the coil?

Do it on the coil it'll live longer and be lower current so cheaper.

Originally Posted by Buford T Justice

Any concern with the fact that the neutrals from both supplies are tied together upstream of the contactor? (red circle in last diagram)?

Yurp. Don't. That'll trip the shore power.
You'll have two neutralisation points if you do that. One on the shore supply upstream shore RCD and one at the inverter.

I generally don't share neutrals with power sources...just loads.

Originally Posted by Buford T Justice

I did check this already, as I know that this would be very bad, and it seems right. I've ordered those thermisters from RS, and I couldn't justify spending 4 quid online so I added a tester to it as well which can help.

They're a disaster since Brexit. If it's on backorder it'll be weeks or months longer than they say. Farnell are shipping from Germany. RS are still shipping via the Uk..."local distributor" me ar$e.

[Buford T Justice]

Originally Posted by Sir Liamalot

Yurp. Don't. That'll trip the shore power.
You'll have two neutralisation points if you do that. One on the shore supply upstream shore RCD and one at the inverter.

I generally don't share neutrals with power sources...just loads.

I'm not sure as to how I can do this then. Out of the changeover I have two lives which are joined and two neutrals which are joined to feed into the single mcb for the sockets supply.

Not withstanding everything else, I should earth the body of the inverter to the neutral of the inverter supply
upstream of the mcb, but this will trip the shore power.

They're a disaster since Brexit. If it's on backorder it'll be weeks or months longer than they say. Farnell are shipping from Germany. RS are still shipping via the Uk..."local distributor" me ar$e.

I believe everything I ordered was in stock, but then again I ordered something from farnell too which was in stock that's now magically on backorder

[Sir Liamalot]

Originally Posted by Buford T Justice

Any concern with the fact that the neutrals from both supplies are tied together upstream of the contactor? (red circle in last diagram)?

That's downstream. Bueno!

[Sir Liamalot]

Originally Posted by Buford T Justice

Not withstanding everything else, I should earth the body of the inverter to the neutral of the inverter supply
upstream of the mcb, but this will trip the shore power.

Inverter Eath linked to Inverter ground and Inverter chassis and Inverter neutral and earth bus, therefore, vehicle chassis! Clear as mud? It won't trip.

[Buford T Justice]

Originally Posted by Sir Liamalot

Inverter Eath linked to Inverter ground and Inverter chassis and Inverter neutral and earth bus, therefore, vehicle chassis! Clear as mud? It won't trip.

Completely

[Sir Liamalot]

To be honest I've never seen anyone else do it right. Most people convince themselves it's too complicated to bother with and compromise safety. I'll draw it later.

Most vans can have an inverter live-earth fault run unflagged.

[Buford T Justice]

Originally Posted by Sir Liamalot

To be honest I've never seen anyone else do it right. Most people convince themselves it's too complicated to bother with and compromise safety. I'll draw it later.

Most vans can have an inverter live-earth fault run unflagged.

Appreciate it.

I've come too far at this point, I want to do it once and do it right.
I ordered those terminals to replace my busbars too. They'll be used to feed the inverter once I get my mits on one

[Sir Liamalot]

This is the result we are looking for with DC protection also.






I just spent €800 on replacement inverter smoke.
Anyone wanna buy a 20kg boat anchor? I have a selection..

Originally Posted by Buford T Justice

Appreciate it.
I ordered those terminals to replace my busbars too.

These are more suitable.
That style in the picture are more single output like for connecting the Engine battery in the house electrics distribution.


I must start stocking terminal fuses.

[Sir Liamalot]

Delay On, Delay Off Relay

[Buford T Justice]

Thanks for this - I appreciate it. It makes more sense now.

My local electrical factor has this, I assume it's the same - multi function timer relay.

What software are you using to draw the diagrams?

[Sir Liamalot]

Oops....the coil control above is for a Delay on relay. Delay On-Off is a little more involved.



Input voltage can be battery.
The trigger switch would have to be another relay with the coil powered from shore power and the switching dry contacts connected to the "S" on the delay relay.

[Sir Liamalot]

Originally Posted by Buford T Justice

My local electrical factor has this, I assume it's the same - multi function timer relay.

Dunno the Delay On - Delay Off in one package are hard to find and Schneider seem to be better than Garo I'm noticing.


Garo isn't very helpful, I can't find a datasheet that says what the functions of the multi-functional relay are..?


It implies it can delay-on and delay-off...I expect that means but not at the same time so get two.

Originally Posted by Buford T Justice

What software are you using to draw the diagrams?

Smartdraw but my "licence" for it has expired and it's expensive get a new one. I can't seem to find one of those made in Russia licenses.

[Sir Liamalot]

thuther option is lose the delay and the two relays and just use one.



Not ideal either. If it breaks the compressor of the fridge firing the contacts will arc and might hurt the inverter.

The cheapest option is a centre off manual.