Electric Hook Up when engine running?

[VanBlanc]

Our current T5 has a Sargent EC155 that takes care of things but I don't like it. So for our T6 I will use a Victron 12/10 charger and Merlin Smartgauge from @travelvolts and either up rate or double the battery.

Currently if I have the leisure power (230V & 12V) switched on at the master it cuts off as soon as the vehicle ignition is turned on. This is good because it avoids leave some kit on. Without that feature if I have the van on mains hook up the charger will be live so what happens if I start the van as it will supply power to the battery and therefore the charger? The Sargent system takes care of this because it kills the 230V/12V supplies as soon as the ignition is on. This might be an advantage for the water pump and rear lights however we are using a diesel hob which has a cool down cycle which I presume means the fan is powered so we don't want to kill that on the vehicle ignition.

 

[Pauly]

If you want to kill the mains when ign is turned on you could interrupt the mains supply with a simple 240V contactor with a 12v coil fed from ign circuit, this will disconnect mains the moment you key on ?
Simple but effective but you would need to consider any side effects of breaking any mains kit you have under under load, assuming you are running off of standard 16A shore power a decent contactor around 30-40A would be more than capable of interrupting this repeatedly under full load but consider what mains equipment will be running and if this would upset it
If your mains is purely running a charger and your equipment is all 12V this would not be a problem but it would not isolate any 12V kit as your previous setup does, that may be best achieved by an auxiliary isolator on 2nd battery circuits so you can choose if you want it turned off or not and this isolator could be mechanical or electrically operated if you wanted to hide it away somewhere and operate from a remote switch on dash or under seat etc ??

 

[VanBlanc]

I could do that easily but now I read it perhaps KISS is the best option. So a simple isolator with an LED for each function is the obvious choice.

I think my biggest concern is what happens if both the alternator and the charger are trying to charge the leisure battery at the same time?

 

[Pauly]

Thats why i think a contactor in the mains supply between the external hookup and the charger, if this contactor is driven by a 12v ignition feed it will open circuit the mains supply as soon as you key on the ignition before the engine start, this will stop the alternator and mains charger both being available at the same time ?
Whats KISS ?

 

[VanBlanc]

Ha! Keep It Simple Stupid!

That is probably the best option. If I use a plug in one at least it will be easy to replace.

 

[VanBlanc]

Looking for a contractor NC would be preferable so that energising it disconnects the entire 230V hook up.

Solid state might be good as would 2P on the load. The load side / consumer unit would have 1 x 6A & 1 x 10A MCBs.

Any thoughts?

 

[Pauly]

Lots of options, if you have room for a larger consumer unit you could get a din rail mounted one and fit in side ? If you wanted a plugin unit may need a seperate enclosure or again could get a din rail mounting base but wouldnt fit properly against cover of fusebox and would take up more space (width)
Most electrical wholesalers would have a variety of them maybe not 12V coil of the shelf but they are relatively common
Heres an example 22.32.0.012.4420 | 22 2 Pole Contactor, 25 A, 2 VA, 12 V Coil | Finder

 

[VanBlanc]

Yes I can probably use the CU but I am confused by that example - are the contacts NO per the description or NC per the spec?

 

[Pauly]

I thought they were NC but thats just a random pull from google