Why won't my generator run my washing machine?

[Keeping Up]

Presumably it meets all the safety regulations appropriate to Planet Zanussi (remember those adverts?) and of course it wouldn't have a Neutral-to-Earth connection, it would have a Neutral-to-Zanussi connection instead.

 

OKOK, I'm just getting my coat ...

[blackrose]

Do you think that this would work with my generator and the Zanussi?

 

It is a 8kva Vetus unit connected with a Victron 3000 multiplus?

 

In our case, the drum will just twitch and then the lights flash. Works OK from inverter or shoreline. I put its lack of working down to poor waveform control but perhaps it wasn't

 

The trouble is I did two things and now I'm not sure which one it was that rectified the problem. It was either that the washing machine locked out because I tried to start it with the generator on eco-mode and it couldn't respond quickly enough to the startup load. When I tried it next with the eco-mode switched off it may have had time to reset itself. Or, it was the earth-neutral link that fixed the problem but Gibbo seems to think that if that was the case then the generator doesn't meet CE safety standards, so perhaps it was the former.

 

If you are running your mains ring from your generator (as opposed to running a single appliance), all the posts I have read from the experts recommend bonding neutral & earth otherwise your RCD will not work in the event of an earth fault - but this is only for a generator with a floating earth and it also requires that your boat's AC system is earth - hull bonded. You also need to connect the earth stud on the chassis of the generator to your hull earth stud. Does your Vetus generator have a floating earth? If not don't neutral-earth bond the cable.

 

Next time you try running the washing machine from the generator make sure that the generator isn't on some sort of eco setting. It needs immediate high output to cope with the washing machine's startup load. Also give the washing machine a bit longer to start - up to a minute - before switching it off and giving up. I still get the end of cycle light flashing when I try to start mine, but after about 40 seconds the start light illuminates and I can start it as normal.

 

Good luck

Edited May 11, 2008 by blackrose

[David]

Do you think that this would work with my generator and the Zanussi?

 

It is a 8kva Vetus unit connected with a Victron 3000 multiplus?

 

In our case, the drum will just twitch and then the lights flash. Works OK from inverter or shoreline. I put its lack of working down to poor waveform control but perhaps it wasn't

 

Drum "twitching" is in my experience due to frequency not being close enough to 50hz for the washing machines motor, it seems machines now use the frequency via their electronics to alter the drum speed, i.e. slow tumble while washing to slow spin then progressivly to fast spin. Our mastervolt 3.5Kva is factory set at 52.5Hz at no load and at first use the Candy 1000T which has minimum electronics anyway would work fine until the final spin which was a progressive slow spin, medium spin then fast spin, it did the first two then just twitched till the timer finished. On M/volt advice adjusting the no load down to 52Hz cured it.

On the earth nutral bond the M/volt is built in Holland and comes with them NOT connected but with a notice attached that for UK use they must be bonded and a simple instruction sheet, the bond link is already in place under the main cable cover just needs swinging across into place.

david

[blackrose]

If you use the generator lead on a different generator with a 'centre tapped earth', it might damage it, so I'd label the lead 'For Honda XXX ONLY!'

 

cheers,

Pete.

 

A PM from another member got me thinking that the cable which has been neutral-earth linked and labelled 'For generator use only, not to be used for shore power' should also be labelled 'For connection from generator to boat only' so that someone doesn't try to use the cable to run a power tool without going through the boat's RCD and hull bonded earth.

[Lesd]

A PM from another member got me thinking that the cable which has been neutral-earth linked and labelled 'For generator use only, not to be used for shore power' should also be labelled 'For connection from generator to boat only' so that someone doesn't try to use the cable to run a power tool without going through the boat's RCD and hull bonded earth.

 

Hope its a long cable Mike, that's a lot of lables !!!

[Gibbo]

A PM from another member got me thinking that the cable which has been neutral-earth linked and labelled 'For generator use only, not to be used for shore power' should also be labelled 'For connection from generator to boat only' so that someone doesn't try to use the cable to run a power tool without going through the boat's RCD and hull bonded earth.

 

Why don't you do it the proper way and link neutral and earth on the generator?

 

Gibbo

[blackrose]

Why don't you do it the proper way and link neutral and earth on the generator?

 

Gibbo

 

Because I wasn't sure where to make that link on the generator and modifying the cable was recommended to me & seemed easier. Besides if someone used a neutral-earth linked generator to run a power tool direct without going through the boat's RCD then surely they would have no protection at all because they'd have no floating earth? So if you make the link on the generator don't you still have to label it?

Edited May 17, 2008 by blackrose

[Gibbo]

Because I wasn't sure where to make that link on the generator and modifying the cable was recommended to me & seemed easier. Besides if someone used a neutral-earth linked generator to run a power tool direct without going through the boat's RCD then surely they would have no protection at all because they'd have no floating earth? So if you make the link on the generator don't you still have to label it?

 

I see your point but if you link neutral and earth in the generator then the output from the genny is exactly the same the national grid. The national grid doesn't have a label on it

 

Gibbo

[blackrose]

I see your point but if you link neutral and earth in the generator then the output from the genny is exactly the same the national grid. The national grid doesn't have a label on it

 

Gibbo

 

The output may be the same as the national grid, but the national grid will generally run through a circuit breaker somewhere along the line, whereas a neutral-earth linked generator that's been mistakenly used by someone to run a power tool direct (because the generator was not labelled), is now not being run through the boat's RCD to protect the user. More importantly the modified generator now has no floating earth! I imagine this could prevent the generator's internal breakers from tripping in the event of an earth fault, but stand to be corrected on that if I'm wrong.

 

In my opinion whichever you modify - cable or generator, you need to label it.

Edited May 17, 2008 by blackrose

[Gibbo]

The output may be the same as the national grid, but the national grid will generally run through a circuit breaker somewhere along the line, whereas a neutral-earth linked generator that's been mistakenly used by someone to run a power tool direct (because the generator was not labelled), is now not being run through the boat's RCD to protect the user. More importantly the modified generator now has no floating earth! I imagine this could prevent the generator's internal breakers from tripping in the event of an earth fault, but stand to be corrected on that if I'm wrong.

 

In my opinion whichever you modify - cable or generator, you need to label it.

 

Right I think I'm with you now. You're saying that because neutral and earth are bonded you need to warn people that they need to use an RCD?

 

I agree with you on the safety point of view but if that's the case, are all the wall sockets at everyones' houses labelled that neutral and earth are bonded?

 

A circuit breaker is not an RCD.

 

The sockets at home are protected with circuit breakers but not necessarily an RCD.

 

Are you saying the extra safety is needed because it's on a boat?

 

The standard expectation of most people is that the power coming from a generator is exactly the same as that coming from the national grid. To NOT bond neutral and earth is to cause confusion and possible problems, not the other way round.

 

Gibbo

[Radio-Ga-Ga]

The Ideal situation is to use an earth rod to take any fault current to earth, if you use the genny with floating, IE no earth, any fault current to a metal cased appliance will not trip the breaker and could be lethal, Gibbo is right, the genny is better wired neutral to earth, not the lead, then no matter what's plugged into it at least the genny's own breaker will trip.

 

A floating earth is a large conductive mass with no direct connection to earth, to which all earths are connected at neutral potential, to protect persons in or on the mass and could apply to a metal boat, building or platform.

[blackrose]

Right I think I'm with you now. You're saying that because neutral and earth are bonded you need to warn people that they need to use an RCD?

 

I agree with you on the safety point of view but if that's the case, are all the wall sockets at everyones' houses labelled that neutral and earth are bonded?

 

A circuit breaker is not an RCD.

 

The sockets at home are protected with circuit breakers but not necessarily an RCD.

 

Are you saying the extra safety is needed because it's on a boat?

 

The standard expectation of most people is that the power coming from a generator is exactly the same as that coming from the national grid. To NOT bond neutral and earth is to cause confusion and possible problems, not the other way round.

 

Gibbo

 

Ok, I'll say it again. All I'm saying is that you need some form of protection. If you neutral-earth bond a generator and then someone uses it direct with an extension lead and power tool then they have NO protection at all (no RCD, no circuit breakers, no floating earth) and that is not the same as the national grid.

 

My argument was not against neutral-earth bonding (either of the cable or the generator), it was FOR neutral earth bonding and labelling.

Edited May 18, 2008 by blackrose

[smileypete]

Ok, I'll say it again. All I'm saying is that you need some form of protection. If you neutral-earth bond a generator and then someone uses it direct with an extension lead and power tool then they have NO protection at all (no RCD, no circuit breakers, no floating earth) and that is not the same as the national grid.

If you use power tools straight off a generator via an extension lead, you still have overcurrent protection from the fuses in the plugs.

 

And although the generators earth wire is bonded to it's own neutral, you still have some extra protection if the generator's earth is isolated from mains earth, as the generator is still effectively an isolated supply.

 

 

However I expect the best protection should come from using a plug in RCD at the generator end, with an earth spike connecting generator earth to ground (Though I would defer to the user manual/makers recommedations).

 

cheers,

Pete.

Edited May 18, 2008 by smileypete

[Gibbo]

Ok, I'll say it again. All I'm saying is that you need some form of protection. If you neutral-earth bond a generator and then someone uses it direct with an extension lead and power tool then they have NO protection at all (no RCD, no circuit breakers, no floating earth) and that is not the same as the national grid.

 

But it IS the same as the national grid. The generator is current limited. It can only provide its rated output. If neutral and earth are bonded that is the same as the national grid. No RCD, neutral earth bonding, a current limit and no label. It IS the same.

 

Gibbo

[blackrose]

But it IS the same as the national grid. The generator is current limited. It can only provide its rated output. If neutral and earth are bonded that is the same as the national grid. No RCD, neutral earth bonding, a current limit and no label. It IS the same.

 

Gibbo

 

So why do Honda and the like make these generators with a floating earth if it is not required - why don't they just bond neutral & earth as you suggest and then let the user either run a mains ring or single appliances from it?

[Gibbo]

So why do Honda and the like make these generators with a floating earth if it is not required - why don't they just bond neutral & earth as you suggest and then let the user either run a mains ring or single appliances from it?

 

I don't know. I wish I did.

 

A simlar thing happened many years ago with inverters. 10 to 15 years ago the big names were Mastervolt, Victron, Heart Interface and Trace. They had about 99% of the market between them with the other 50 or so companies all squabbling over the remaining 1%. For some reason they all bonded neutral/earth on the 110 volt units intended for USA etc but the 230 volt units did not have the bonding. Then with the introduction of the Low Voltage Directive they all started to bond neutral and earth. Why the generator manufacturers are 15 years behind the inverter market baffles me.

 

All the reputable inverter manufacturers bond neutral and earth. One day the generator manufacturers will catch up.

 

As far as I'm concerned they should have neutral/earth bonding and an RCD actually built in.

 

And back to the original point of this thread, I think your washing machine is faulty!

 

Gibbo

Edited May 18, 2008 by Gibbo

[smileypete]

So why do Honda and the like make these generators with a floating earth if it is not required

 

Have a look at:

 

http://www.hondagenerator.co.uk/pages/FAQ.htm

 

"I have bought a generator, and I am concerned about safety. Can I use a personal power breaker?

 

Answer : The generator is configured differently to the mains supply. The generator has a ‘floating earth’, whilst the mains has an earthed neutral. Whereas it is definitely recommended to use a personal power breaker (RCD) from the mains, for the majority of cases, it is not necessary to use one with a B&S generator. The generators are safe as they are designed.

Personal power breakers are designed to operate from the mains. If one is to be used with a generator, then it is necessary to modify the generator so that it is configured in the same way as the mains. This is a relatively simple modification for a qualified electrician involving adding a link wire from the neutral terminal to the earth terminal. However, once the generator has been modified, it is necessary to then always use a personal power breaker and to also always use an earth spike, which connects between the generator frame and the ground. Since this is difficult to ensure, it is generally recommended not to modify the generator."

 

So maybe a modified lead is better than modifying the generator itself.

 

cheers,

Pete.

[Radio-Ga-Ga]

Does anybody know what this alleged floating earth is actualy connected to? I'd be very interested to know how honda consider their 2k kit to be safer than the practice used by the national grid and the best safety devices.

Edited May 18, 2008 by Radio-Ga-Ga

[blackrose]

And back to the original point of this thread, I think your washing machine is faulty!

 

Gibbo

 

Yes, that's what I was beginning to think... It was like that from new but now the warranty's expired

 

I wonder why it doesn't trip the RCBO when the mains ring is run from the generator?

Edited May 19, 2008 by blackrose

[Gibbo]

Does anybody know what this alleged floating earth is actualy connected to? I'd be very interested to know how honda consider their 2k kit to be safer than the practice used by the national grid and the best safety devices.

 

Well there is no earth. The earth of the genny could be considered to be the chassis. But unlike the national grid the two outputs (technically they are hot1 and hot 2 because there is no neutral) are floating from the chassis. It should be called a "floating output" NOT a floating earth. By its very definition earth cannot be floating!

 

The logic behind it is that without an earth bond one can touch one of the outputs and get no electric shock whereas if the bond was made touching live would result in electric shock through the person, down to earth and back to neutral through the bond. Assuming the chassis of the generator was connected to the real earth.

 

The problem is, everyone expects neutral to be bonded to earth because that is what 99.9% of the world's national grids provide.

 

Gibbo

 

Yes, that's what I was beginning to think... It was like that from new but now the warranty's expired

 

I wonder why it doesn't trip the RCBO when the mains ring is run from the generator?

 

Even now you've bonded neutral and earth?

 

Gibbo

[Radio-Ga-Ga]

Thanks for that I was totaly mystified at the difference between my understanding of a floating earth and Honda's, I also noted Honda used the expression "in most cases". In most cases hand held power tools are class 2 (double insulated) so the question of earthing is irrelevent, personnaly I would still go for bonding earth/neutral at the output.

 

BTW if earth stops floating we could all be in for a bumpy ride

[Arnot]

Does anybody know what this alleged floating earth is actualy connected to? I'd be very interested to know how honda consider their 2k kit to be safer than the practice used by the national grid and the best safety devices.

Actually they do supply a "guide to users" that covers the topic of floating and tied earths on their generators with them when sold. A pdf of it can be obtained from Honda on request but doesn't seem to be on their website. If you can't get hold of it, PM me and I will forward the pdf.

 

Also there is an HSE Document that give some guidance on the topic which might help.

 

Regards

 

Arnot

[blackrose]

Even now you've bonded neutral and earth?

 

Gibbo

 

That's right. It does take a while for the washing machine to want to start from the generator. The end of cycle still flashes (about 10 or 11 flashes) and this happens 2 or 3 times but eventually the start light illuminates and I'm able to start the machine. I've only done 3 washes since leaving the mooring but the RCBO hasn't tripped. When I was on shore power it would trip almost every time I plugged the washing machine in - even with no load applied (before switching it on). Perhaps one time out of 10 it wouldn't trip.

Edited May 20, 2008 by blackrose

[Gibbo]

That's right. It does take a while for the washing machine to want to start from the generator. The end of cycle still flashes (about 10 or 11 flashes) and this happens 2 or 3 times but eventually the start light illuminates and I'm able to start the machine. I've only done 3 washes since leaving the mooring but the RCBO hasn't tripped. When I was on shore power it would trip almost every time I plugged the washing machine in - even with no load applied (before switching it on). Perhaps one time out of 10 it wouldn't trip.

 

Ok, here goes..... I'm going to diagnose this by remote control and telepathy!

 

Two points you need to understand to follow me......

 

On a normal mains supply with an RCD, if you short neutral and earth with no load switched on nothing happens. If you then start to draw increasing power from the supply, the live current will be whatever it is, the neutral current will be half as much (assuming the neutral and earth conductors are the same size) because the return current will be shared between the neutral and earth conductors. So as the load current is increased you reach a point where you are drawing 60mA and are actually drawing 60mA down the live wire and returning 30mA up each of the neutral and earth wires. This is the point where the RCD trips. It detects the imbalance of 30mA between the live and neatral. With it so far?

 

On a normal supply, the neutral earth bond could be some distance away, in the case of a marina it could easily be hundreds of metres away. This means that with lots of loads on, shared between lots of users, there could be a substantial voltage difference between the neutral conductor and the earth conductor without causing any problems. All due to the resistance of the supply cables. With your neutral earth bonded generator this cannot happen as the bond is so much closer to the load. Follow that?

 

A washing machine has the motor and its speed control triac connected directly to the live and neutral. That has to be the case obviously.

 

What is less well known is that very often the computer and it's power supply are also connected directly to the mains. The computer is actually at mains potential and its power supply is by way of a capacitor dropper as opposed to the more expected transformer. This saves a few pence in manufacture as no transformer is needed and no galvanic isolation between the computer and the triac controlling the motor speed. The capacitive dropper power supply is the reason many washing machines actually blow up when run from MSW inverters as the harmonics cause excess voltage on the regulator feeding the computer.

 

Now this power supply (purely for the computer) is connected between live and neutral with two "Y" capacitors, one connected between live and earth, the other connected between neutral and earth. If something has gone wrong there, maybe a dodgy solder joint or a blown capacitor, it is quite conceivable that the power supply for the computer is trying to draw its power from between live and earth. This is a very low power circuit, milliAmps. However you will instantly see that the unit will not work without a neutral earth bond, further it will also be causing an imbalance between the live and neutral currents of a few milliAmps. This would be further compounded by a voltage difference between the neutral and earth.

 

I'm sure you can draw your own conclusions from this.

 

Gibbo

[Yoda]

Very good explanation.