Inverter question (1 Viewer)

[Dave K]

I am considering fitting an inverter to our van, at the moment I have 2 x 100ah batteries and a 140w solar panel and I'm going to add a further 150w panel to the roof in the near future, the biggest draw will be a hairdryer which will be around 900w but I'm thinking it would be better to go with a bigger inverter to cope with start up? I have looked through various past threads and Sterling inverters seem to be popular and I understand I need a pure version, any other recommendations would be welcome. It would be ideal if I could site the inverter on the opposite side of the van to the batteries, is this possible, it would probably mean a 3m run with the cables.
Thanks in advance.
Dave

 

[Richard n Ann]

I really would try and keep the inverter close to the battery, but I suppose it depends how inconvenient that would be. With those currents, I'd be doing my best to keep it within half a metre. Our 1000w pure sine wave inverter is Chinese and would run the Babyliss 750w styler at a push (Ann loves it) but she's been able to let it dry naturally or use the toilet block so far. Runs the GHDs ok

 

[Richard n Ann]

Duplicated post sorry

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[Two on Tour]

I fitted a 1000 watt pure sine wave inverter mainly to run my wife's hair dryer. Her hair dryer at home is a 2200 watt jobby so no chance of running it sensibly on our camper.
We ended up getting her one of these,

http://www.ebay.co.uk/itm/Diva-Radi...885186?hash=item3d39b0adc2:g:VgMAAOSwll1Wu1PP

My wife has very long hair and the hair dryer/brush above takes about twice as long as her home hair dryer.

It only draws 450 watts flat out and that's because it uses infra red heat instead a heating element which needs more power.
Inverter manufactures quote the peak power available which they can only be used for a very short time, you usually need to half the peak power value as a working power that can be maintained. A 1000 watt inverter is quite a sizeable bit of kit to find a home for and as Richard and Ann said, it should to be very close to the battery it's powered from.
To make ours practical to use, I have mounted a 3 pin socket outlet in a convenient panel near to the inverter with a flex to it plugged into the inverter, effectively an extension lead and our inverter has a remote on/off switch which mounted next to the outlet socket in the panel. Our inverter is designed to cutout when the supply battery drops below 10.8 volt and it does not take many minutes to reach that with our 110 amp hab battery so I normally run the van engine to maintain the required voltage.
A bit of a simplistic description but it gives you an idea of our set up.

 

[funflair]

Short runs and big cables are the way to go with big inverters, if you get the Sterling or Merlin they have optional remote switches if getting access for switching on/off is the issue.

Around 1500 watts should do you OK.

Martin

 

[Two on Tour]

Items such tooth brushes and shavers that don't have a 12 volt charger we usually charge via the 240 inverter while we are on the move.

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[Tinker2]

I have a 2000 ring inverter pure sine, twin sockets, on a similar set up to the one you have batterys close to inverter, added a a remote switch and socket on wall, next job is extra socket on opposite side of M/h when the flexi conduit turns up, cable has to be protected under vehicle.

 

[scotjimland]

Cable length should be kept as short as possible to minimise volt drop.

As length increases so to does cable size.

for example..

A 1kw inverter , at full load it pulls 84amps , I will allow 3% losses

1mt cable length, size req. = 10 mm2

2mt cable length, size req.= 25 mm2

3 mt cable length, size req. = 35 mm2

do your own cable sizing calculations here:

http://www.solar-wind.co.uk/cable-sizing-DC-cables.html

 

[Dave K]

I fitted a 1000 watt pure sine wave inverter mainly to run my wife's hair dryer. Her hair dryer at home is a 2200 watt jobby so no chance of running it sensibly on our camper.
We ended up getting her one of these,

View attachment 165620

http://www.ebay.co.uk/itm/Diva-Radi...885186?hash=item3d39b0adc2:g:VgMAAOSwll1Wu1PP

My wife has very long hair and the hair dryer/brush above takes about twice as long as her home hair dryer.

It only draws 450 watts flat out and that's because it uses infra red heat instead a heating element which needs more power.
Inverter manufactures quote the peak power available which they can only be used for a very short time, you usually need to half the peak power value as a working power that can be maintained. A 1000 watt inverter is quite a sizeable bit of kit to find a home for and as Richard and Ann said, it should to be very close to the battery it's powered from.
To make ours practical to use, I have mounted a 3 pin socket outlet in a convenient panel near to the inverter with a flex to it plugged into the inverter, effectively an extension lead and our inverter has a remote on/off switch which mounted next to the outlet socket in the panel. Our inverter is designed to cutout when the supply battery drops below 10.8 volt and it does not take many minutes to reach that with our 110 amp hab battery so I normally run the van engine to maintain the required voltage.
A bit of a simplistic description but it gives you an idea of our set up.

Thanks for that, that might be the way forward as she also uses a hot brush but that's only 200w so at least I could save some money by just getting the 1000w inverter.

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[Dave K]

Short runs and big cables are the way to go with big inverters, if you get the Sterling or Merlin they have optional remote switches if getting access for switching on/off is the issue.

Around 1500 watts should do you OK.

Martin

Thanks Martin, the batteries are in our biggest locker so I was hoping to re site the inverter to make the most of our storage which is quite tight anyway but needs must. Would you know how much of a job it is to connect the inverter so that all of the 240v sockets become usable?

 

[Dave K]

I have a 2000 ring inverter pure sine, twin sockets, on a similar set up to the one you have batterys close to inverter, added a a remote switch and socket on wall, next job is extra socket on opposite side of M/h when the flexi conduit turns up, cable has to be protected under vehicle.

Thanks for the info, and have you found that your set up copes ok with that size inverter?

 

[Dave K]

Cable length should be kept as short as possible to minimise volt drop.

As length increases so to does cable size.

for example..

A 1kw inverter , at full load it pulls 84amps , I will allow 3% losses

1mt cable length, size req. = 10 mm2

2mt cable length, size req.= 25 mm2

3 mt cable length, size req. = 35 mm2

do your own cable sizing calculations here:

http://www.solar-wind.co.uk/cable-sizing-DC-cables.html

Thanks Jim, I was thinking I would have to run the cables inside the van but is it possible to run them underneath with protection?

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[funflair]

When we bought our van it had a Quasi sine wave inverter at the end of about 8 metres of very heavy cable but it would still trip on low voltage and the Quasi bit seemed pretty useless at running the microwave and a non starter for the Nespresso machine, I purchased a new Pure sine Merlin with remote and placed it about 1.5 metres from the batteries but used the same cable 85mm sq and it works great now, this is a long winded way of saying that the mains wiring was already done for ours and yes it runs all the van's 240v except the battery charger and includes an automatic changeover from mains to inverter.

I guess the answer is its not much of job if you know what you are doing, but it is 240 volts so needs doing properly, I dont know if I would or could have done ours if the basic work hadn't been done already.

Martin

 

[scotjimland]

Thanks Jim, I was thinking I would have to run the cables inside the van but is it possible to run them underneath with protection?

yes, run them in flexible conduit or whatever you have to hand.. mine go under between the seats in PVC conduit.

Also have a 1kw inverter from Sunshine Solar with remote controller, and have wired in three x 13A CBE sockets and a USB outlet from the same supply, fused separately.

The 12v supple cable goes between the bench and the battery under the drivers seat, I used mini-trunking to protect it.. cable run is less than 1 mt

http://www.sunshinesolar.co.uk/prod...Sine_Wave_Sunshine_Power_Inverter/VP1000.html

 

[olley]

Unless your hairdryer has some pretty sophisticated electronics in it, it will run quite happy of a modified/quasi sine wave inverter. I have been using a Sterling 1800watt modified sine wave inverter for ten years, and have yet to find something that wont run on it, and that includes phone chargers.

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[Two on Tour]

Have a scout around eBay and inverter supplier to get an idea of how big in dimensions these inverters are because they may be bigger than you think.
If you can mount the inverter close to the supply battery to keep the 12 volt cable run down then do the long runs with the 240 cable as the voltage drop is a lot less, just be aware of the safety aspects of 240 cable runs.
There might be some issues with connecting into your normal 240 system in that the inverter may not like the back feed on the 240 side and normally your 240 EHU will come in via circuit breakers and mabye your control panel in turn may play up your battery charge as it could be then in an odd type charging and supply loop.

 

[Wagoneer]

Items such tooth brushes and shavers that don't have a 12 volt charger we usually charge via the 240 inverter while we are on the move.

I remember hearing somewhere that electric toothbrushes shouldn't be charged using an inverter because of the inductive method used to charge the toothbrush. There have been reports of toothbrushes being destroyed.

Perhaps "pure sine wave inverters" are OK but "modified sine wave inverters" are not? I have a quasi sine wave inverter which I think is the same as the "modified" type.

Anyone know if my hearsay is correct?

 

[Richard n Ann]

Make a lead up and plug it into your EHU socket. Trip the charger MCB otherwise the battery will be trying to charge itself

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[Richard n Ann]

I remember hearing somewhere that electric toothbrushes shouldn't be charged using an inverter because of the inductive method used to charge the toothbrush. There have been reports of toothbrushes being destroyed.

Perhaps "pure sine wave inverters" are OK but "modified sine wave inverters" are not? I have a quasi sine wave inverter which I think is the same as the "modified" type.

Anyone know if my hearsay is correct?

Correct, pure sine wave is ok

 

[Tinker2]

Had the panel and inverter fitted 135w panel, 2× 100 w batteries. Nice to stop for a cup of coffee ( electric kettle) wifes happy hair dryer, tv all runs ok. I like the remote switch as it saves opening up the bottom locker to turn on, dead easy to fit as the sockets.

 

[funflair]

Have a scout around eBay and inverter supplier to get an idea of how big in dimensions these inverters are because they may be bigger than you think.
If you can mount the inverter close to the supply battery to keep the 12 volt cable run down then do the long runs with the 240 cable as the voltage drop is a lot less, just be aware of the safety aspects of 240 cable runs.
There might be some issues with connecting into your normal 240 system in that the inverter may not like the back feed on the 240 side and normally your 240 EHU will come in via circuit breakers and mabye your control panel in turn may play up your battery charge as it could be then in an odd type charging and supply loop.

The inverter needs to be connected so that it is isolated from the 240v circuit if another mains source is connected or at the very least manually switched, anything else could prove deadly.

Martin

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[peterc10]

You do not need to go to the expense of a pure sine wave inverter if all you are doing is using the hair dryer. It will work perfectly well with quasi sine wave, as will most other electrical items. Pure sine wave really only needed for inductive charging items such as electric toothbrushes as well as some microwaves.

 

[Dave K]

yes, run them in flexible conduit or whatever you have to hand.. mine go under between the seats in PVC conduit.

Also have a 1kw inverter from Sunshine Solar with remote controller, and have wired in three x 13A CBE sockets and a USB outlet from the same supply, fused separately.

The 12v supple cable goes between the bench and the battery under the drivers seat, I used mini-trunking to protect it.. cable run is less than 1 mt

http://www.sunshinesolar.co.uk/prod...Sine_Wave_Sunshine_Power_Inverter/VP1000.html

View attachment 165631 View attachment 165632

That's a great help Jim thanks
The inverter seems a decent price as well.

 

[Dave K]

You do not need to go to the expense of a pure sine wave inverter if all you are doing is using the hair dryer. It will work perfectly well with quasi sine wave, as will most other electrical items. Pure sine wave really only needed for inductive charging items such as electric toothbrushes as well as some microwaves.

It'll be used for charging the toothbrush, Hoover, iPhones and iPads, I read somewhere that the pure sine wave inverters were the way to go for these items.

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[peterc10]

It'll be used for charging the toothbrush, Hoover, iPhones and iPads, I read somewhere that the pure sine wave inverters were the way to go for these items.

Iphone and ipad are charged using a bog standard 5V DC USB charge. Therefore the best bet is to buy a 12V USB adapter and charge them using that. which works really very well. Otherwise you are using an inefficient 12V DC up to 240V AC inverter and then using another inefficient 240V AC to 5V DC transformer to take it back down again.

Not sure what hoover you have so can't comment on that. We use a 12V one that does fine for us.

As I already said the inductive charger on the toothbrush is the problem. So we just buy an . Lasts about 3 or 4 weeks and then we only have to buy 2 more AA batteries. In fact you could use rechargeable AA batteries and a 12V charger for them.

 

[Dave K]

Iphone and ipad are charged using a bog standard 5V DC USB charge. Therefore the best bet is to buy a 12V USB adapter and charge them using that. which works really very well. Otherwise you are using an inefficient 12V DC up to 240V AC inverter and then using another inefficient 240V AC to 5V DC transformer to take it back down again.

Not sure what hoover you have so can't comment on that. We use a 12V one that does fine for us.

As I already said the inductive charger on the toothbrush is the problem. So we just buy an . Lasts about 3 or 4 weeks and then we only have to buy 2 more AA batteries. In fact you could use rechargeable AA batteries and a 12V charger for them.

Thanks Peter, certainly worth considering.