Typical power use.

[Happy Jack]

Hello all.
Am currently planning swap from AGM to Lithium.
Apart from lights and phone/laptop charging our main current draw is the fridge/freezer at approx 52A in 24 hours. Maxxfan irregular usage.
Diesel hob pulls 4Ah and usage about 2 hours a day.
Diesel heater used in winter, but we only go for a few days at a time then.
Will be getting Fogstar (at least 300A), a B2B, an Inverter and a suitable Charger.
We have 300W of solar going through a Victron100/30 MPPT.
Will be powering a double socket outlet and initially using it for a travel kettle, hair dryer, portable induction hob and so on as and when necessary.
I'm confident that we will be OK with the above arrangements,
BUT, thinking about future proofing e.g. if the diesel hob knacked up and couldn't be repaired we would get a double slip in induction hob.
And of course extra Amps availability generates more need for other things.
For our initial needs a Victron 1200 watt inverter would be OK I think but with the above in mind am thinking a 2000W at least might be needed for future proofing.
A couple of questions,
Do any of you use an induction hob and how much does it typically take out of your batteries?
(Have looked at a hob from 12v planet, max output is 1800W which would be 150Amps, that's a lot to take from your battery even if you used it for just 1 hour).
Can I wire the socket outlet in the pic below directly from the inverter?

Anything else I need to know?

 

[autorouter]

Can I wire the socket outlet in the pic below directly from the inverter?

This exact socket in the picture is not suitable, but similar ones are available which are suitable. There are a number of issues.

First, the switches on the sockets are single pole. These are fine for UK domestic circuits, but not suitable for motorhome circuits which should have either double pole switches or no switches at all.

Next, the type of RCD (active or passive) is important. A passive RCD will stay switched on if the power fails, then comes back on. Passive RCDs are used for fridges and freezers, to avoid having to switch all the RCDs back on every time you switch the inverter on, or disconnect and reconnect the hookup cable. You probably want a passive RCD for a motorhome. An active RCD switches off if the power fails, so is safer if powering machinery, to avoid unexpected restart of a machine if power resumes after a cut.

A Victron inverters like the 1200 has the AC output neutral connected to the case of the inverter. The case needs to be connected to the vehicle chassis and the earth terminal of the socket. That will allow the RCD to function correctly, improving protection for the user if multiple appliances are in use. This arrangement is different from many other brands of inverter, which usually have a floating neutral, not connected to the case or to the earth terminal.

It's a good idea to use a socket tester with an RCD Test function to test the socket once it is installed, to check that wiring has been done correctly and the RCD works OK. Note that pressing the RCD test button on the socket itself only tests the trip mechanism, not whether it has been wired correctly.

 

[LostInSpace]

A couple of questions,

I think you need to take professional advice.

 

[Happy Jack]

This exact socket in the picture is not suitable, but similar ones are available which are suitable. There are a number of issues.

First, the switches on the sockets are single pole. These are fine for UK domestic circuits, but not suitable for motorhome circuits which should have either double pole switches or no switches at all.

Next, the type of RCD (active or passive) is important. A passive RCD will stay switched on if the power fails, then comes back on. Passive RCDs are used for fridges and freezers, to avoid having to switch all the RCDs back on every time you switch the inverter on, or disconnect and reconnect the hookup cable. You probably want a passive RCD for a motorhome. An active RCD switches off if the power fails, so is safer if powering machinery, to avoid unexpected restart of a machine if power resumes after a cut.

A Victron inverters like the 1200 has the AC output neutral connected to the case of the inverter. The case needs to be connected to the vehicle chassis and the earth terminal of the socket. That will allow the RCD to function correctly, improving protection for the user if multiple appliances are in use. This arrangement is different from many other brands of inverter, which usually have a floating neutral, not connected to the case or to the earth terminal.

It's a good idea to use a socket tester with an RCD Test function to test the socket once it is installed, to check that wiring has been done correctly and the RCD works OK. Note that pressing the RCD test button on the socket itself only tests the trip mechanism, not whether it has been wired correctly.

It will be the only socket outlet we will have for appliances so having to reset it every time won't be a problem.
I do have a socket tester.
However, not being double pole would be a problem; but why would it need to be double pole in a van?
I already have a double pole consumer unit in the van for the EHU but it only supplies the battery charger via a single socket outlet at the moment.
We can and have unplugged the charger occasionally to use the single socket outlet but that was only at home (van EHU plugged in to home outside power) and that was to use a dehumidifier.
Would I be better off wiring the inverter to the consumer unit(and should I use a 2 way switch so that ordinary mains and inverter mains cannot be on at same time) and would the charger and appliance socket outlets still need to be double pole ?
Thanks for your reply.

 

[MisterB]

52Ah in 24 hours for a fridge freezer is a massive draw ....... perhaps trying to find a way to reduce that consumption is worth your time .... there are plenty of youtube videos re wiring of inverters/batteries etc, view quite a few to get a 'feel' for what needs to be done, but dont take all of them as gospel.

 

[Happy Jack]

52Ah in 24 hours for a fridge freezer is a massive draw ....... perhaps trying to find a way to reduce that consumption is worth your time .... there are plenty of youtube videos re wiring of inverters/batteries etc, view quite a few to get a 'feel' for what needs to be done, but dont take all of them as gospel.

Ours is a 12V compressor Fridge/Freezer and takes an average of 2.2Ah.

 

[MisterB]

Ours is a 12V compressor Fridge/Freezer and takes an average of 2.2Ah.

Is there no facility to set it at reduced power overnight? Ours has a night time mode. .

 

[Happy Jack]

Is there no facility to set it at reduced power overnight? Ours has a night time mode. .

No, it's this one.

 

[HappyDays-NI]

We have pretty much the same set up. 3way fridge though. Our battery hasn't fallen below 85% so far. Either driving or hookup charges it up. When off EHU, the solar tops up the battery always. We were off grid for about a week recently.

 

[autorouter]

but why would it need to be double pole in a van?

The hazard is that the live and neutral could be reversed, and then the single-pole switch would switch off only the neutral, leaving the live still connected. This could be a problem with some faulty appliances. Or even ones that are not faulty, such as switching off the toaster and extracting a slice of toast with a metal knife.

In the UK, house sockets are wired so that breaker protection is only on the live, and the installation is checked and certified that the wiring is correct. Once installed, it won't be changed, except by an electrician who will re-certify it. In that situation you can get away with having a single pole switch only on the live conductor, and it is guaranteed to switch off the power. Sockets for UK plugs often have single-pole switches, but increasingly they have double pole switches, it's just a case of searching for a suitable one.

For mobile installations like a motorhome, and in all other parts of the world except the UK, the approach is to always switch both live and neutral conductors. All switches have to be double pole, and the protective breakers are all double pole too. However it is often not necessary to have a switch on the socket, so often the socket is unswitched.

If you haven't already bought the socket, then find a similar socket with double pole switches. If you have already bought the item in the photo, then you could test the socket fed from the inverter, and ensure that the live and neutral are wired the correct way round, and not reversed. Then the single-pole switch would definitely switch off the live, so it would be be safe.

 

[autorouter]

If you haven't already bought the inverter then maybe you could consider a Multiplus inverter/charger instead of a separate inverter and charger. The Multiplus has many advantages over separate inverter and charger if you are often using a hookup connection, especially if the hookup is low power like on many camp sites and aires. If you never use hookup, there's not much advantage.

 

[Bertilak]

With regard to your question re power use, I'd say you need to consider your use profile, especially out of season. Esp. how long you expect to drive per day, how long you'll be off hook-up without solar ( low sun angle in autumn or shady med summer aires).
With a similar minimal setup, we've found our fridge, fan, lights and chargers have been taking c35-40 Ahrs per day, giving about a week before driving or plugging in, on our 315 Fogstar. The120w of solar is barely doing anything in Oct, even on the med.
With only a 30A b2b, a full charge needs 10 hours of driving, so we could be carrying a deficit over a few days. This battery is oversized for us, but gives us that ability. If you want electric cooking, you probably need to reveiw the whole user case vs charging regime.

 

[MichaelT]

We have just cooked tea using an induction hob at 800w and an air fryer 1700w.

We have 510ah lithium and cooking tea for 25 minutes has used 16% max draw was about 220a intermittently see below graph.

Ours is wired to the consumer unit but not earthed as nothing we use is earthed.

 

[herald_400rl]

3 days cooking (sometimes twice a day) with induction hob/air fryer, heating via diesel heater, fridge running (off a 240v inverter with 8w average standby), TV for a couple hours a day. With a 535w solar panel (low yield in this weather) and no b2b we got home with 50% remaining of 630ah.

Cooking on gas/other fuel I suspect nearer 80% (or more).

 

[LostInSpace]

Cooking on gas ...

Now, that is what I like to hear.

 

[MisterB]

So far we have managed around 5-6 days off grid purely on electric as we have no gas. Everything electric and 240v for all 'appliances' with around 600Ah of lithium.

Diesel heating and hot water ....

It's so much more convenient...

 

[Happy Jack]

The hazard is that the live and neutral could be reversed, and then the single-pole switch would switch off only the neutral, leaving the live still connected. This could be a problem with some faulty appliances. Or even ones that are not faulty, such as switching off the toaster and extracting a slice of toast with a metal knife.

In the UK, house sockets are wired so that breaker protection is only on the live, and the installation is checked and certified that the wiring is correct. Once installed, it won't be changed, except by an electrician who will re-certify it. In that situation you can get away with having a single pole switch only on the live conductor, and it is guaranteed to switch off the power. Sockets for UK plugs often have single-pole switches, but increasingly they have double pole switches, it's just a case of searching for a suitable one.

For mobile installations like a motorhome, and in all other parts of the world except the UK, the approach is to always switch both live and neutral conductors. All switches have to be double pole, and the protective breakers are all double pole too. However it is often not necessary to have a switch on the socket, so often the socket is unswitched.

If you haven't already bought the socket, then find a similar socket with double pole switches. If you have already bought the item in the photo, then you could test the socket fed from the inverter, and ensure that the live and neutral are wired the correct way round, and not reversed. Then the single-pole switch would definitely switch off the live, so it would be be safe.

Had that metal clad outlet many years, never got used until now.
See your point about wiring being reversed and although I would test for that we will part company with the van someday and it is better to have it safe now.
Have ordered a BG black double pole 2 hang socket outlet to replace it.
Will have to wire the inverter directly to the rccd consumer unit and since we do use hook up occasionally will also go through a selector switch first.
I would need rccd protection of course?
Does that sound good?

 

[Happy Jack]

If you haven't already bought the inverter then maybe you could consider a Multiplus inverter/charger instead of a separate inverter and charger. The Multiplus has many advantages over separate inverter and charger if you are often using a hookup connection, especially if the hookup is low power like on many camp sites and aires. If you never use hookup, there's not much advantage.

Havn't got inverter yet and the Sargent charger I have isn't suitable for Lithium so I will need a charger as well but rarely use site hook up. Lots to think about.

 

[wfdTamar]

Victron inverters are labelled as VA, so what is 1200VA is actually less continuous watts (watts are what most inverters use). You'd need the 1600VA, maybe even the 2000VA.

A 1200 watt one would be pushing it to do what you describe. I have a 1400 watt one that does a lower power air fryer and espresso machine. Hair dryer will also likely be demanding. I would consider either a Victron multiplus 2000 (expensive but good and safe), or a Creabest inverter (cheaper and can be hooked up to power outlets). They do one with a charger too.

If you intend connecting in a standard inverter to your van mains circuit it is really not easy. I now know enough to know it's not as simple as you might think. If you don't do it correctly you open yourself up to danger and insurance claims being denied.

300Ah is the minimum with that fridge (it's a thirsty one) and the bigger appliances you describe (induction). I'd even consider a bigger battery if you intend long off grid use or in bad solar weather, minimal driving.

 

[LostInSpace]

watts are what most inverters use

Inverters don't use watts.

They give them out.

 

[MisterB]

Havn't got inverter yet and the Sargent charger I have isn't suitable for Lithium so I will need a charger as well but rarely use site hook up. Lots to think about.

This might be of interest if you're considering a new inverter/charger ... I only fitted it yesterday so can't really recommend it but it might be worth considering ...

There are a couple of you tube videos on this model, comparing them with others and showing detailed installation instructions.

Bullet bitten .... New inverter charger on its way

I've never really been happy with my current inverter charger, it performs really well but I just don't have the space for it, which is a shame as it has handed everything it's ever been asked to do AND more (powered a 3.2kw kettle when needed ..) I've gone for another Renogy, this time the...

www.motorhomefun.co.uk

 

[Rozzer]

Hello all.
Am currently planning swap from AGM to Lithium.
Apart from lights and phone/laptop charging our main current draw is the fridge/freezer at approx 52A in 24 hours. Maxxfan irregular usage.
Diesel hob pulls 4Ah and usage about 2 hours a day.
Diesel heater used in winter, but we only go for a few days at a time then.
Will be getting Fogstar (at least 300A), a B2B, an Inverter and a suitable Charger.
We have 300W of solar going through a Victron100/30 MPPT.
Will be powering a double socket outlet and initially using it for a travel kettle, hair dryer, portable induction hob and so on as and when necessary.
I'm confident that we will be OK with the above arrangements,
BUT, thinking about future proofing e.g. if the diesel hob knacked up and couldn't be repaired we would get a double slip in induction hob.
And of course extra Amps availability generates more need for other things.
For our initial needs a Victron 1200 watt inverter would be OK I think but with the above in mind am thinking a 2000W at least might be needed for future proofing.
A couple of questions,
Do any of you use an induction hob and how much does it typically take out of your batteries?
(Have looked at a hob from 12v planet, max output is 1800W which would be 150Amps, that's a lot to take from your battery even if you used it for just 1 hour).
Can I wire the socket outlet in the pic below directly from the inverter?
View attachment 1279692
Anything else I need to know?

I went for 314ah Fogstar Eco, Fogstar charger, Victron 100/50 MPPT for my 150w solar which I might add to. Victron Orion XS 12/50, renogy shunt, renogy 3000w invertor. Changed fridge to Coolmatic, good so far, fitted microwave above. Sockets wired to invertor which takes care of switching on EHU. Just came back from 5 week 2,500 miles in Europe, no problems other than Lead starter battery ( 5 yrs old) gave up in Hungary! Calculation was sunny days panel would cover fridge consumption and potential off grid 5 days plus. Not tried that yet, max was 3 days, no probs.

 

[Lenny HB]

Victron inverters are labelled as VA, so what is 1200VA is actually less continuous watts (watts are what most inverters use). You'd need the 1600VA, maybe even the 2000VA.

Cheaper inverters may say 2000 watts but it's actually VA, so you need to allow for that.

 

[Happy Jack]

Victron inverters are labelled as VA, so what is 1200VA is actually less continuous watts (watts are what most inverters use). You'd need the 1600VA, maybe even the 2000VA.

A 1200 watt one would be pushing it to do what you describe. I have a 1400 watt one that does a lower power air fryer and espresso machine. Hair dryer will also likely be demanding. I would consider either a Victron multiplus 2000 (expensive but good and safe), or a Creabest inverter (cheaper and can be hooked up to power outlets). They do one with a charger too.

If you intend connecting in a standard inverter to your van mains circuit it is really not easy. I now know enough to know it's not as simple as you might think. If you don't do it correctly you open yourself up to danger and insurance claims being denied.

300Ah is the minimum with that fridge (it's a thirsty one) and the bigger appliances you describe (induction). I'd even consider a bigger battery if you intend long off grid use or in bad solar weather, minimal driving.

Might have forgotten to mention.
We have 300W of solar going though a Victron MPPT and we have always been OK from mid March through to early September. Rarely down below 70% SOC.
Our 2 off 95Ah AGM batteries are 5 years old now and they have been below 50% on a few occasions, usually early March and late,September.
Learnt our lesson and when away outside of March to September we usually do sites with hook up and keep them charged up.
We are thinking at least 300Ah Lithium and will be getting a big enough Invertert.
At the moment we have just the hook up to do charging and the double socket outlet was going to be a stand alone spur fed by the Inverter. Will have to consider how to make that safe.

 

[Happy Jack]

This might be of interest if you're considering a new inverter/charger ... I only fitted it yesterday so can't really recommend it but it might be worth considering ...

There are a couple of you tube videos on this model, comparing them with others and showing detailed installation instructions.

Bullet bitten .... New inverter charger on its way

I've never really been happy with my current inverter charger, it performs really well but I just don't have the space for it, which is a shame as it has handed everything it's ever been asked to do AND more (powered a 3.2kw kettle when needed ..) I've gone for another Renogy, this time the...

www.motorhomefun.co.uk

Will have a look at that, thanks.

 

[Happy Jack]

Cheaper inverters may say 2000 watts but it's actually VA, so you need to allow for that.

Yrs, might have to bite the bullet and get a 3000Ah model even though our needs are low at the moment.
Thinking of future proofing.
EG, if our diesel hob ever knacked up and coudn't be repaired it would be much cheaper to simply put an induction hob in it's place.
At the moment our 240 power needs will be limited to boiling a travel kettle now and then, hair dryer and minor appliances. We don't envisage taking an air dryer or Remoska Tec with us.

 

[Happy Jack]

I went for 314ah Fogstar Eco, Fogstar charger, Victron 100/50 MPPT for my 150w solar which I might add to. Victron Orion XS 12/50, renogy shunt, renogy 3000w invertor. Changed fridge to Coolmatic, good so far, fitted microwave above. Sockets wired to invertor which takes care of switching on EHU. Just came back from 5 week 2,500 miles in Europe, no problems other than Lead starter battery ( 5 yrs old) gave up in Hungary! Calculation was sunny days panel would cover fridge consumption and potential off grid 5 days plus. Not tried that yet, max was 3 days, no probs.

How does the Renogy take care of switching on EHU?
Is the inverter wired to the Consumer unit ?

 

[Raul]

Victron inverters are labelled as VA

Every power supply is VA at source, every transformer, inverter and even your incoming mains at the house. In order to become KW you need to know the PF.

so what is 1200VA is actually less continuous watts

It's less if load has a negative power factor. It's equal if power factor is 1, no inductive reactance. At supply is full apparent power, at load is VA times power factor.
KW= VA x PF. PF=( XL-Xc)+R

watts are what most inverters use

The inverter uses smooth DC no power factor no reactance, simply VxA=Wdc.

The AC VA output, it will never be equal to the KW output, except for resistive loads with negligible resistance, that gets rounded of to power factor 1. Then all the VA output it can be delivered to the load in KW absorbed.
But most of our everyday loads have inductance reactance, lots of it, therefore the power factor can be high as 0.95 or low as 0.6. And for joe public, Victron rounded this figure in the middle to cover most loads to 0.8 PF; that results in 1200VA x 0.8 PF = 960W. In reality, if my load is a heater( resistive), I will get the full 1200W to the load. Consequently, if I connect a hair drier with dc drivers, inductors and dc converters, the power factor may be 0.6 and the 1200VA will be reduced to 720W at load. The rest of the watts are reactive and return back as unusable power, they are far too much out of the wave form( lagging) that has no use.
This, is all because of the load, not the supply. And this is true for every AC power supply, not just inverters.

 

[MisterB]

How does the Renogy take care of switching on EHU?
Is the inverter wired to the Consumer unit ?

It depends on which inverter you buy. the 1000/2000/3000W inverters can be wired to the consumer unit and automatically supply power from the EHU with nothing else to do in terms of switching it on. Its often referred to as 'pass through'. The only time you need to switch them on, is when you're not on EHU and relying solely on power from the battery.

You don't need to wire them to the consumer unit, they can just as easily function independent of 'mains' power, converting battery DC to AC, but of course they would need to be switched on. The power they supply is accessed via the UK style plugs fitted to the inverter itself. You would also need to check as to whether you needed to install a N-G bond for when connected to the EHU.

The one ive just removed MUST be turned on to allow 'pass through', it is the PCL 3000w inverter/charger ..... note the difference, the PCL is an inverter/charger whereas the initial ones i mentioned are purely an inverter. The PCL also requires a N-G bond for when connected to the EHU

The one i installed yesterday, the Renogy HF 3000w inverter/charger operates in much the same way as the 1000/2000/3000W, inverter BUT it is an inverter/charger, we dont need to turn it on when connected to the EHU, it automatically allows 'pass through' and turns on and off itself, the bonus being that if the EHU is a 'low supply' ie 3 or 6A as you might find on some continental sites, the manual says that the inverter will immediately sense when drawing more than 3/6A and will supplement the supply from the battery ..... From what i understand, that is how the Victron inverters work, i am unable to test that function so i cant guarantee it actually works, but why wouldnt it if the manual specifically states it? The new inverter also has a very simple to install N-G bonding option, its just one screw and takes 10 seconds to install!

Although i am VERY happy with the new inverter so far, i am reluctant to recommend it until its been put through its paces ...

FYI i know that Vanbitz/Wattguardz install the Renogy Rego version (not sure what the difference actually is?) so perhaps the new Renogy inverter/chargers are starting to challenge the long established and reliable Victron Multiplus range at a much less cost??

 

[Happy Jack]

It depends on which inverter you buy. the 1000/2000/3000W inverters can be wired to the consumer unit and automatically supply power from the EHU with nothing else to do in terms of switching it on. Its often referred to as 'pass through'. The only time you need to switch them on, is when you're not on EHU and relying solely on power from the battery.

You don't need to wire them to the consumer unit, they can just as easily function independent of 'mains' power, converting battery DC to AC, but of course they would need to be switched on. The power they supply is accessed via the UK style plugs fitted to the inverter itself. You would also need to check as to whether you needed to install a N-G bond for when connected to the EHU.

The one ive just removed MUST be turned on to allow 'pass through', it is the PCL 3000w inverter/charger ..... note the difference, the PCL is an inverter/charger whereas the initial ones i mentioned are purely an inverter. The PCL also requires a N-G bond for when connected to the EHU

The one i installed yesterday, the Renogy HF 3000w inverter/charger operates in much the same way as the 1000/2000/3000W, inverter BUT it is an inverter/charger, we dont need to turn it on when connected to the EHU, it automatically allows 'pass through' and turns on and off itself, the bonus being that if the EHU is a 'low supply' ie 3 or 6A as you might find on some continental sites, the manual says that the inverter will immediately sense when drawing more than 3/6A and will supplement the supply from the battery ..... From what i understand, that is how the Victron inverters work, i am unable to test that function so i cant guarantee it actually works, but why wouldnt it if the manual specifically states it? The new inverter also has a very simple to install N-G bonding option, its just one screw and takes 10 seconds to install!

Although i am VERY happy with the new inverter so far, i am reluctant to recommend it until its been put through its paces ...

FYI i know that Vanbitz/Wattguardz install the Renogy Rego version (not sure what the difference actually is?) so perhaps the new Renogy inverter/chargers are starting to challenge the long established and reliable Victron Multiplus range at a much less cost??

At the moment my EHU is connected to this consumer unit.
Which is then wired straight through to the Sargent charger.
If I go the route of separate inverter and charger then I'll simply swap to a Lithium compatible charger.
For 240V I was thinking of an Inverter fed by the battery via an on/off switch then straight through to the only double socket outlet we would have, via an inline RCD. The metal clad in post #1 is only single pole and I've now got a double pole black socket outlet on order to replace it (it goes with our colour scheme). Daft I know but not my idea.
Hence the inline RCD.
Our needs will be very simple.
The inverter won't be a regular use item.
Unless.....as I said before about the diesel hob if it ever knacked up.