which inverters provide neutral earth bonding

[riccol1966]

Hi, although I am not using inverters in the marine sense, I have used your forum before as a great intro to the world of mains power from a battery source. I have experimented so far with modified and pure sine inverters and generators. Right now, I have a Kipoint inverter (Taiwan sourced), which outputs a split 115v on live and 115 on neutral. I have been told by the manufacturer that I cannot bond neutral to earth as that would blow the fuses on it.

 

In this configuration, certain motors appear more strained, coffee machines and microwaves make odd noises, and a UPS supply will not function at all. Swapping over to my trusty Honda EU20i genny gives perfect results, because the output from the genny is neutral-earth bonded, which I have done as per manufacturers instructions.

 

So, can someone with lots of knowledge of inverters advise which models allow you to bond neutral and earth thus achieving 230V on live and 0 on neutral. I know that Mastervolt do it, but who else does it also?

 

Finally, any of you experienced boaters notice any difference in running appliances in both modes (115/115 and 230/0) ?

 

Thanks and regards.

[Gary Peacock]

Hi, although I am not using inverters in the marine sense, I have used your forum before as a great intro to the world of mains power from a battery source. I have experimented so far with modified and pure sine inverters and generators. Right now, I have a Kipoint inverter (Taiwan sourced), which outputs a split 115v on live and 115 on neutral. I have been told by the manufacturer that I cannot bond neutral to earth as that would blow the fuses on it.

 

In this configuration, certain motors appear more strained, coffee machines and microwaves make odd noises, and a UPS supply will not function at all. Swapping over to my trusty Honda EU20i genny gives perfect results, because the output from the genny is neutral-earth bonded, which I have done as per manufacturers instructions.

 

So, can someone with lots of knowledge of inverters advise which models allow you to bond neutral and earth thus achieving 230V on live and 0 on neutral. I know that Mastervolt do it, but who else does it also?

 

Finally, any of you experienced boaters notice any difference in running appliances in both modes (115/115 and 230/0) ?

 

Thanks and regards.

 

Victron do also.

[Dylan]

Sterling 3KW PSW appearstobond earth and neutral, judging by voltages recorded by myself. I have never peered inside to establish a link though.

[PeterF]

I have a PowerMaster 1800W pure sine wave which is earth to neutral bonded, I can not remember if I did it or if it came like that. I previously had a PowerMaster 650W pure sine wave that I bonded earth to neutral without any problem.

[Arnot]

Hi, although I am not using inverters in the marine sense, I have used your forum before as a great intro to the world of mains power from a battery source. I have experimented so far with modified and pure sine inverters and generators. Right now, I have a Kipoint inverter (Taiwan sourced), which outputs a split 115v on live and 115 on neutral. I have been told by the manufacturer that I cannot bond neutral to earth as that would blow the fuses on it.

 

In this configuration, certain motors appear more strained, coffee machines and microwaves make odd noises, and a UPS supply will not function at all. Swapping over to my trusty Honda EU20i genny gives perfect results, because the output from the genny is neutral-earth bonded, which I have done as per manufacturers instructions.

 

So, can someone with lots of knowledge of inverters advise which models allow you to bond neutral and earth thus achieving 230V on live and 0 on neutral. I know that Mastervolt do it, but who else does it also?

 

Finally, any of you experienced boaters notice any difference in running appliances in both modes (115/115 and 230/0) ?

 

Thanks and regards.

I don't think that your immediate problem is anything to do with the 115+115 configuration, I think it is to do with the waveform. The symptoms you describe are typical of the sort of thing that happens with a square wave or modified square wave inverter. By the way, my term "modified square wave" is normally translated by the marketing departments of the inverter sales companies to "modified sine wave" but that's a whole old thread.

 

My experience is that most inverters that measure 115+115 can be modified to 230vAC merely by physically bonding them but there are a few exceptions. There are a couple of clues that can help, first with the inverter downpowered and disconnected from its supply for a few minutes, check the resistance between the phases and earth, if the result is very high (100kΩ plus) and rises steadily from the time the meter is connected then this is a good sign. Then, with the inverter connected and running test (with care) the actual voltage between each phase wire and the earth, if the two voltages are slightly different this is a good sign as well.

 

If both of these work out then with the inverter running, connect a low wattage bulb (preferably a 115v one) between each of the phases and the earth in turn and measure the voltage across the bulb, if it is virtually zero in both cases then you can almost certainly bond one of the phase wires to the protective earth to create a neutral.

 

WARNING - there is a risk attached to this and even if all the tests indicate that it should be OK there may still be a problem and the inverter may be damaged beyond repair. Also if you are not familiar with working with mains voltages then it's best to leave it to someone who is, these things can kill.

 

I have to say however if the inverter you have is one of the modified square wave types it will never be very successful and it's probably best ditched an a better one purchased...

 

The process is one that I have used when I have come across an inverter that is not bonded in an installation where it has to be and for my purposes if it doesn't work out nothing has been lost because the inverter would have to be changed out anyway. It is not an ideal method but sometimes the best of a bad job, possibly Gibbo could be more informative on this one.

 

Finally, if the waveform is pure sine, there should be no difference as far as an appliance is concerned between 115=115 and 0 - 230 supplies but the same cannot be said of some circuit protection devices.

 

Regards

 

Arnot

Edited May 8, 2008 by Arnot

[Gibbo]

Any equipment that has a problem running from +/- 115 volts has either been designed deliberately that way (to ensure neutral earth bonding and correct polarity - some early import American inverters were like this) or is broken. The load should not care either way and should operate properly whether neutral and earth are bonded, whether they are unbonded or whether the source is centre tapped (+/- 115 volt). If the equipment won't run then it does not comply with CE and it is against the law to sell it in the EU and has been for several years.

 

The problem with a centre tapped supply is that what we consider to be neutral is now in effect another live and yet we use single pole fuses and circuit breakers.

 

For a centre tapped source ALL switches and circuit breakers MUST be dual pole.

 

As Arnot pointed out it is more likely that the problem lies with the waveform shape.

 

Those that bond neutral/earth that I am aware of are....

 

All Sterling inverters over 500 Watts.

Mastervolt Dakar.

Mastervolt Mass.

Trace truck power.

Trace SW series.

Trace XW series.

Heart Freedom series.

Heart EMS series.

All Victrons.

All PowerMaster.

 

Those that will allow it to be done are.

 

Statpower (Xantrex) Prowatt 800 and 1500 Watt (but not the 75, 150 or 300) and all their clones.

Statpower ProSine series.

All Sinergex.

All Rich Electric.

 

The only ones I am aware of that will NOT allow it to be done are all below 500 Watts. The Electrolux travelpower cannot be neutral earth bonded.

 

Most combis can be done but it needs to be done internally via a relay (that is usually already present) otherwise it trips the incoming RCD when on shorepower. Most combis are in fact already bonded.

 

Gibbo

[riccol1966]

Any equipment that has a problem running from +/- 115 volts has either been designed deliberately that way (to ensure neutral earth bonding and correct polarity - some early import American inverters were like this) or is broken. The load should not care either way and should operate properly whether neutral and earth are bonded, whether they are unbonded or whether the source is centre tapped (+/- 115 volt). If the equipment won't run then it does not comply with CE and it is against the law to sell it in the EU and has been for several years.

 

The problem with a centre tapped supply is that what we consider to be neutral is now in effect another live and yet we use single pole fuses and circuit breakers.

 

For a centre tapped source ALL switches and circuit breakers MUST be dual pole.

 

As Arnot pointed out it is more likely that the problem lies with the waveform shape.

 

Those that bond neutral/earth that I am aware of are....

 

All Sterling inverters over 500 Watts.

Mastervolt Dakar.

Mastervolt Mass.

Trace truck power.

Trace SW series.

Trace XW series.

Heart Freedom series.

Heart EMS series.

All Victrons.

All PowerMaster.

 

Those that will allow it to be done are.

 

Statpower (Xantrex) Prowatt 800 and 1500 Watt (but not the 75, 150 or 300) and all their clones.

Statpower ProSine series.

All Sinergex.

All Rich Electric.

 

The only ones I am aware of that will NOT allow it to be done are all below 500 Watts. The Electrolux travelpower cannot be neutral earth bonded.

 

Most combis can be done but it needs to be done internally via a relay (that is usually already present) otherwise it trips the incoming RCD when on shorepower. Most combis are in fact already bonded.

 

Gibbo

 

Gibbo, many thanks for the list and taking the time to reply. Sorry for the late response as I did not have my profile set to remind me when someone replies. It's an interesting subject which I will be retuning to in my ongoing renewable energy efforts - totally agree that most folk assume there will be no power on the neutral until the circuit is completed, and indeed I had a specific double pole circuit breaker added to my set-up to handle the 115/115 inverter output. I will check out that list of inverters,

 

Regards

 

R.

[Guest TerryL]

Hi, although I am not using inverters in the marine sense, I have used your forum before as a great intro to the world of mains power from a battery source. I have experimented so far with modified and pure sine inverters and generators. Right now, I have a Kipoint inverter (Taiwan sourced), which outputs a split 115v on live and 115 on neutral. I have been told by the manufacturer that I cannot bond neutral to earth as that would blow the fuses on it.

 

In this configuration, certain motors appear more strained, coffee machines and microwaves make odd noises, and a UPS supply will not function at all. Swapping over to my trusty Honda EU20i genny gives perfect results, because the output from the genny is neutral-earth bonded, which I have done as per manufacturers instructions.

 

So, can someone with lots of knowledge of inverters advise which models allow you to bond neutral and earth thus achieving 230V on live and 0 on neutral. I know that Mastervolt do it, but who else does it also?

 

Finally, any of you experienced boaters notice any difference in running appliances in both modes (115/115 and 230/0) ?

 

Thanks and regards.

 

I have the same inverter in 24 Volt 3KW which I'm very pleased with for the price. It runs a small kettle, a toaster, a Baby Belling and a microwave plus other smaller items all ok, but not all at the same time of course. Mine appears to have 150 - 0 - 91 volts oddly enough. I've briefly looked inside and it has two full length circuit boards which appear identical. The socket line wiring is black and blue with a green yellow centre earth linked on each board which then appears to also be earthed to the casing at the other end.

 

It would appear that the inverter could be altered to earth/neutral by disconnecting and isolating the green/yellow from the casing and the sockets and by linking the casing to the socket earth and then the neutral. The only concern would be if the neutral/earth and the battery negative were linked as per normal and if there was a voltage present between them which I haven't checked yet. The sockets are not the same polarity so would need changing and the new neutral internal fuse would need to be bridged. I'll probably go into it a bit more sometime and see if I can convert it to neutral/earth.

[Smelly]

Those that bond neutral/earth that I am aware of are....

 

All Sterling inverters over 500 Watts.

 

Gibbo

 

Remember my 1k Sterling qpower?

 

I'm happy to be told it was a QC problem and it should have been earth/neutral bonded, but it wasn't. Thanks again tho!