inverter help :)

hi all new here right so am upgrading my inverter set up in my work van i use this set up for tools and camping the new inverter going in is a

Victron Phoenix Inverter 12V 2000Va Smart what i am trying to work out is will i need to run it in to a 240v consumer unit RCD /MCB. my old ivereter just had plug socket on side i did run that with a rcd spur

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Its only 8 amps so you don't really need that much complexity. Good plan to have an RCD in the circuit, make sure you ground the inverter properly otherwise it'll do nowt.

thanks for getting back to me the inverter dose have a 5000w surge not that it would be hitting that much if at all . here is some of what it says in manual ive found online .


This is a Safety Class I product (supplied with a protective grounding terminal). The chassis must be grounded. A grounding point is located on the outside of the product. Ensure that the DC and AC input cables are fused and fitted with circuit breakers. ...


The neutral wire of the AC output of this inverter is connected to the chassis (see appendix B for 1600VA/2000VA and appendix C for 3000VA/5000VA). This is to ensure proper functioning of a GFCI (or RCCB) to be installed in the AC output of the Inverter. The chassis of the product must be connected to ground, to the frame (of a vehicle) or the ground plate or hull (of a boat)

Yup, what it says. You'll need chunky cables from battery to dc input, have the RCBO electrically as near the inverter as possible. 6mm min for your grounding wire, 10mm wouldn't be overkill (@ericmark has much knowledge on this sort of setup)

steve cooper said:

The neutral wire of the AC output of this inverter is connected to the chassis (see appendix B for 1600VA/2000VA and appendix C for 3000VA/5000VA). This is to ensure proper functioning of a GFCI (or RCCB) to be installed in the AC output of the Inverter. The chassis of the product must be connected to ground, to the frame (of a vehicle) or the ground plate or hull (of a boat)

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As the manufacturer has done that, then you must fit an 30mA RCD for additional protection, if the manufactuer hadn't done that then there would be two routes you could follow:

a) check it was OK to do so, and make the connection yourself and fit an RCD
b) use it as a floating (ungrounded / IT) system for once piece of equipment only, this without an RCD.

But the manufacturer has already decided its going to be TN, so you need a 30mA RCd for your socket

Adam_151 said:

As the manufacturer has done that, then you must fit an 30mA RCD for additional protection, if the manufactuer hadn't done that then there would be two routes you could follow:

a) check it was OK to do so, and make the connection yourself and fit an RCD
b) use it as a floating (ungrounded / IT) system for once piece of equipment only, this without an RCD.

But the manufacturer has already decided its going to be TN, so you need a 30mA RCd for your socket

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its dose say you can change the neutral wire and make it floating but think i will look at a small consumer unit . ive seen one on a well known selling site with 63amp 2 pole 30ma with a 16amp and a 32 amp mcb would this be over kill ?

oldbutnotdead said:

Yup, what it says. You'll need chunky cables from battery to dc input, have the RCBO electrically as near the inverter as possible. 6mm min for your grounding wire, 10mm wouldn't be overkill (@ericmark has much knowledge on this sort of setup)

Click to expand...

ive got 4m of 70mm2 cable to link 4x 120ah batterys and link inverter i also run a 20 amp ctek d250sa slipt charge set up and will be adding the ctek smartpass 120 to it . will then charge at 140 amps when driving so need to have the bigger cable 4 that also plus inline 300amp fuses

Adam_151 said:

As the manufacturer has done that, then you must fit an 30mA RCD for additional protection, if the manufactuer hadn't done that then there would be two routes you could follow:

a) check it was OK to do so, and make the connection yourself and fit an RCD
b) use it as a floating (ungrounded / IT) system for once piece of equipment only, this without an RCD.

But the manufacturer has already decided its going to be TN, so you need a 30mA RCd for your socket

Click to expand...

just re read this so i could just change the sockets ive got in the van to 30ma rcd ones ?

We are given examples like this in BS 7671, and it does seem a 30 mA RCD is recommended which makes sense when you consider your in a metal box, unless you are exporting the supply from the inverter to items outside the metal box, then no real need for an earth, just bonding.

I used an inverter in a narrow boat, and the shore supply went to a class II battery charger, so shore earth was not imported, but it does depend on how the batteries are charged. Look at electric cars and we see the problem with earthing. Why the electric car is not class II not a clue.

But if we look at a tooth brush supply, we consider it safe with a TT as only one item can be plugged in, and the same applies to an inverter, with an inverter supply to one item there is no real need for a RCD or earth system, in fact it can make it more dangerous not less, but with multiple low voltage items (230 volt) type 1 used at the same time one may develop a line 1 to earth fault and another line 2 to earth fault so you can have 230 volt touching two items, so we bond and line 2 becomes a neutral.

So to quote

The following monitoring devices and protective devices may be used:
(i) Insulation monitoring devices (IMD's)
(ii) Residual current monitoring devices (RCM's)
(iii) Insulation fault location systems
(iv) Over current protective devices
(v) RCD's

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and the designer has to decide which is the most appropriate method. To be frank with a bank of class II battery chargers I would not be worried if non were used, but once you start using class I then you have to assess the risk and select the appropriate method, and to do that remotely is not really the way to do it.

I have been approached at work far too many times by some one asking advice, and too many times after I have visited them and realised they had not really told me what they were doing and my advice was wrong as a result. So would say get some one to actually look at what you are doing.

What size battery do you have? 2000 W at 12v is 166amps. A standard battery will in theory last 15 minutes, in practice with that sort of load around 5 minutes.

winston1 said:

What size battery do you have? 2000 W at 12v is 166amps. A standard battery will in theory last 15 minutes, in practice with that sort of load around 5 minutes.

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He has already said

steve cooper said:

I've got 4m of 70mm2 cable to link 4x 120ah batteries and link inverter i also run a 20 amp ctek d250sa slipt charge set up and will be adding the ctek smartpass 120 to it . will then charge at 140 amps when driving so need to have the bigger cable 4 that also plus inline 300amp fuses

Click to expand...

So it seems he does realise how much power an inverter uses. Personally I would keep traction battery and inverter batteries independent and use a DC to DC inverter to charge the inverter batteries, but this is a personal preference, there is nothing really wrong with other methods.

Son had two independent alternators on his narrow boat, both 70 amp, however to recharge is mainly down to time not amps with lead acid. A very small 3.8 amp charger with a half charged 90 Ah battery is still dropping output after 4 hours so as not to damage the battery.

For fast recharge forget lead acid, my e-bike uses a lithium-ion battery, small powerful and fast recharge, but even a 10 Ah costs around £200, so not a cheap option.