Quick question about wiring up an Inverter

[DHutch]

... Or does your boat have a centre tapped supply and no shoreline...

If inverter is centre tapped as tested, and the the jobs now been done which I expect it has, then yes that is exactly what we are talking about.

 

 

Daniel

[Sea Dog]

I presume you noticed that it's an Indian organisation.

Ah-ha! No, I didn't! Well, that explains quite a lot, I suppose! Thanks for enlightening me, Nick.

[pete.i]

Well I hope that you now know how to do it Dan. After that lot I'm even more confused than before. It would seem that no-one really knows at least that was the impression I got from this thread whilst trying to skirt round the arguments.

 

Pete. sa (Sod All)

[Paul C]

Well I hope that you now know how to do it Dan. After that lot I'm even more confused than before. It would seem that no-one really knows at least that was the impression I got from this thread whilst trying to skirt round the arguments.

 

Pete. sa (Sod All)

 

My reading of the thread, is that some people know exactly what they're talking about, and some are floundering.

[nicknorman]

http://www.igfa.org/images/SpeciesID_Images/flounder_summer.png

[Graham.m]

I presume you noticed that it's an Indian organisation.

Doesn't matter what country it is, that one has a goodish reputation

 

My reading of the thread, is that some people know exactly what they're talking about, and some are floundering.

Would you like to illuminated us?

[Paul C]

 

Would you like to illuminated us?

 

I don't need to add anything, there's 6 pages of stuff which everyone can read already.

[Graham.m]

 

I don't need to add anything, there's 6 pages of stuff which everyone can read already.

Well I just hope people with shoreline don't have travel powers or whatever they are called.

 

I am told that they can be modified.

[BMC problems]

Well I hope that you now know how to do it Dan. After that lot I'm even more confused than before. It would seem that no-one really knows at least that was the impression I got from this thread whilst trying to skirt round the arguments.

 

Pete. sa (Sod All)

 

Unfortunately that is the overwhelming impression gained from silly arguments.

 

Doesn't matter what country it is, that one has a goodish reputation

 

 

 

It certainly is spoken of in glowing terms; "He had no doubt that those who are graduating today will add further luster to the illustrious record of IETE which enjoys enviable reputation for academic excellence and course curriculam"

 

I hope that its ambassador in England makes up in luster [sic] what he lacks in knowledge.

[cuthound]

Well I just hope people with shoreline don't have travel powers or whatever they are called.

I am told that they can be modified.

Travel Powers are engine driven 230 volt ac generators, therefore unlikely to be used in conjunction with a connected shore line. Most boats have a selector switch to enable only one source of ac power to be connected at any one time (combi's excepted, as they often have a facility to parallel with the shore line.

[nicknorman]

Travel Powers are engine driven 230 volt ac generators, therefore unlikely to be used in conjunction with a connected shore line. Most boats have a selector switch to enable only one source of ac power to be connected at any one time (combi's excepted, as they often have a facility to parallel with the shore line.

Yes ours has either shore power or Travelpower automatically selected by a clever box (shore power has priority IIRC), then fed into the Combi. Obviously you can't mix shore power and TP since there is no phase or frequency matching. When the Combi is working as a pure inverter it operates the NE bond relay, when it is passing through power from the shore or TP it doesn't, since the shore is of course NE bonded anyway and the TP is bonded at mid-point. So with any of those 3 possible power sources the subsequent RCD works correctly.

[Graham.m]

Travel Powers are engine driven 230 volt ac generators, therefore unlikely to be used in conjunction with a connected shore line. Most boats have a selector switch to enable only one source of ac power to be connected at any one time (combi's excepted, as they often have a facility to parallel with the shore line.

 

Standards are written for a reason to keep people safe to a minimum standard. It seems some boaters like to pick and chose the bits they will follow. However I suspect they will be the first to scream if something goes wrong

[Paul C]

 

Standards are written for a reason to keep people safe to a minimum standard. It seems some boaters like to pick and chose the bits they will follow. However I suspect they will be the first to scream if something goes wrong

 

Yeah but Nick's explained how his system complies with the regulations, even though it uses both a centre-tapped generator and a N-E bonded shoreline. The main reason being the earth bonding is done at the point of generation (ok lets not get into whether the shoreline is IT, TT, TN-C, TN-S, TN-C-S, etc etc - but the point is still valid).

[Graham.m]

 

Yeah but Nick's explained how his system complies with the regulations, even though it uses both a centre-tapped generator and a N-E bonded shoreline. The main reason being the earth bonding is done at the point of generation (ok lets not get into whether the shoreline is IT, TT, TN-C, TN-S, TN-C-S, etc etc - but the point is still valid).

 

Its probably PME or some other rarified version The discussion was not about Nick's system. But if you want to go there, outlets are single pole, requirement has always been double pole. Nick seems unable to grasp that on a centre tapped supply a failure of insulation of the supply that would cause a trip on a neutral earthed system will not cause the standard UK 30mA trip to trip. Also from what I have seen of about a 60 plus installation with centre tapped sources, they did not comply they had been installed into (for want of a better word) standard AC installations.

 

Interestingly I have the 24V version of the Victron 350 IEC sockets, and mine is neutral bonded to earth.

Edited December 10, 2015 by Graham.m

[Loafer]

 

It probably PME. The discussion was not about Nick's system. But if you want to go there, outlets are single pole, requirement has always been double pole. Nick seems unable to grasp that on a centre tapped supply a failure of insulation of the supply that would cause a trip on a neutral earthed will not cause the standard UK 30mA trip to trip. Also from what I have seen of about a 60 plus installation with centre tapped sources, they did not comply they had been installed into (for want of a better word) standard AC installations.

 

Interestingly I have the 24V version of the Victron 350 IEC sockets, and mine is neutral bonded to earth.

 

Was that 'protective multiple earth'? Or was it a mis-spelling?

[DHutch]

Its probably PME or some other rarified version

I would apologise for going of topic.... but while I accept there will be old and or non-complient installations, as far as I am aware it jolly well ort not to be!

 

"Due to the (small) risks of the lost neutral raising 'earthed' metal work to a dangerous potential, coupled with the increased shock risk from proximity to good contact with true earth, the use of TN-C-S supplies is banned in the UK for caravan sites and shore supply to boats, and strongly discouraged for use on farms and outdoor building sites, and in such cases it is recommended to make all outdoor wiring TT with RCD and a separate earth electrode."

 

http://electrical.theiet.org/wiring-matters/41/marinas.cfm

 

Daniel

[cuthound]

I would apologise for going of topic.... but while I accept there will be old and or non-complient installations, as far as I am aware it jolly well ort not to be!

"Due to the (small) risks of the lost neutral raising 'earthed' metal work to a dangerous potential, coupled with the increased shock risk from proximity to good contact with true earth, the use of TN-C-S supplies is banned in the UK for caravan sites and shore supply to boats, and strongly discouraged for use on farms and outdoor building sites, and in such cases it is recommended to make all outdoor wiring TT with RCD and a separate earth electrode."http://electrical.theiet.org/wiring-matters/41/marinas.cfm

Daniel

My understanding is that the above is now a requirement of BS7671 IET Wiring Regulations, however they are not retrospective and only apply to older instsllstions when they are modified. Certainly I had a dedicated earth spike installed when providing a dedicated shore supply for my boat.

 

Edited to clarify that the wiring regulations are not retrospective.

Edited December 11, 2015 by cuthound

[Graham.m]

I would apologise for going of topic.... but while I accept there will be old and or non-complient installations, as far as I am aware it jolly well ort not to be!

 

"Due to the (small) risks of the lost neutral raising 'earthed' metal work to a dangerous potential, coupled with the increased shock risk from proximity to good contact with true earth, the use of TN-C-S supplies is banned in the UK for caravan sites and shore supply to boats, and strongly discouraged for use on farms and outdoor building sites, and in such cases it is recommended to make all outdoor wiring TT with RCD and a separate earth electrode."

 

http://electrical.theiet.org/wiring-matters/41/marinas.cfm

 

Daniel

 

Perhaps if you had read the comment fully "Its probably PME or some other rarefied version " You would have got the implied I don't know and understood that I did not think it was relevant to what was being talked about. I am quite sure that any Electricity Supply company putting a supply into a marina after the 2002 PME regs and 17th Edition of the Wiring Regulations in 2008 came out would meet the correct safety standard. However is that retroactive on marinas installed pre 2002 and have they all been brought up to that standard. I wonder knowing what I have seen at some of the marinas I have visited and heard about.

 

As someone who plays with kWs of RF I am well aware of the shortcomings of PME, I have an earth mat over a metre square to overcome those short comings. Hence the way I made the comment.

 

Somewhere you mentioned dropping a live mains extension board over the side and the trips not going off, I got the feeling that it did not concern you overly or did it. What this thread was about was wiring a centre-tapped source into a boat safely.

 

I note that apparently you have discounted the company's email about the earthing on their own product.

 

I am wondering if some people see boating as an area where it is OK to cut corners do the absolute minimum or ignore, what they can get away with, it does not matter we do what we want when we want. I don't know wondering

[Dave-Shrop]

Loafer Posted 07 December 2015 - 05:20

 

our Apple TV box keeps flashing its 'on' light, whilst plugged into a 'switched off' mains socket. Presumably because it still has 120VAC on its neutral which isn't switched.

 

That is because most electronic devices use " Switch Mode Power Supply (SMP) " instead of a transformer, and one of the DC output poles is earthed, if connected to a 240 volt centre tapped earthed you will have all funny voltages appearing. Also some of these SMP's have small capacitors connected earth to reduce the Electromagnetic interference (EMI), which is caused by the high frequency switching of SMP. Equipment Designed and CEI approved for connection to 240 volt negative earthed system should not be connected to a 240 volt Centre tapped earthed system.

[nicknorman]

That is because most electronic devices use " Switch Mode Power Supply (SMP) " instead of a transformer, and one of the DC output poles is earthed, if connected to a 240 volt centre tapped earthed you will have all funny voltages appearing. Also some of these SMP's have small capacitors connected earth to reduce the Electromagnetic interference (EMI), which is caused by the high frequency switching of SMP. Equipment Designed and CEI approved for connection to 240 volt negative earthed system should not be connected to a 240 volt Centre tapped earthed system.

However if the equipment doesn't have a connected earth pin, eg the Apple TV Loafer mentioned, iPhone /iPad and other USB chargers and lots of other stuff these days, there can be no difference between centre tapped 230v and polarised 230v since the equipment has no earth reference. Early SMPSs did have capacitors to earth but this is frowned upon these days and pretty sure such equipment would not get a CE approval these days. By the way, what is a "240 volt negative earthed system". Perhaps it's something they have in India?

[Graham.m]

However if the equipment doesn't have a connected earth pin, eg the Apple TV Loafer mentioned, iPhone /iPad and other USB chargers and lots of other stuff these days, there can be no difference between centre tapped 230v and polarised 230v since the equipment has no earth reference. Early SMPSs did have capacitors to earth but this is frowned upon these days and pretty sure such equipment would not get a CE approval these days. By the way, what is a "240 volt negative earthed system". Perhaps it's something they have in India?

 

I read that as neutral earthed system that is what I believe the poster meant. We don't all have perfect diction nor perfect writing skills and I don't believe people should be knocked for that.

 

"...but this is frowned upon these days and pretty sure such equipment would not get a CE approval these days" Could you please give us evidence of this?

 

Ed. Surely the earth reference in any equipment of this nature is the earth bonded neutral they are designed to be connected to. I believe CE tests are done on earth bonded neutral supplies and surely the use of the equipment on an AC system using a centre-tapped earth, (leaving both live connector floating above earth), invalidates the CE test as the method of use is not as intended by the manufacturer or the CE test.

Edited December 11, 2015 by Graham.m

[Dave-Shrop]

Why do people purchase 240 volt Centre tapped earthed system, when they are using UK 240 volt Neutral earthed designed equipment, is it because they are cheaper. By time you comply with the requirements for 240 volt Centre tapped earthed system I cannot see it is cheaper. Victron make Inverters suitable for the 240 volt Neutral earthed UK system. The 240 volt Centre tapped earthed system is made for the Domestic market of North America and Canada.

[Loafer]

Why do people purchase 240 volt Centre tapped earthed system, when they are using UK 240 volt Neutral earthed designed equipment, is it because they are cheaper. By time you comply with the requirements for 240 volt Centre tapped earthed system I cannot see it is cheaper. Victron make Inverters suitable for the 240 volt Neutral earthed UK system. The 240 volt Centre tapped earthed system is made for the Domestic market of North America and Canada.

 

I wasn't aware of the difference when I bought mine. There was no mention of what sort of earth it had.

[Paul C]

 

I wasn't aware of the difference when I bought mine. There was no mention of what sort of earth it had.

 

Where did you buy it? Marina, chandlery, online (from Victron themselves, or eBay, etc etc)?

[nicknorman]

Why do people purchase 240 volt Centre tapped earthed system, when they are using UK 240 volt Neutral earthed designed equipment, is it because they are cheaper. By time you comply with the requirements for 240 volt Centre tapped earthed system I cannot see it is cheaper. Victron make Inverters suitable for the 240 volt Neutral earthed UK system. The 240 volt Centre tapped earthed system is made for the Domestic market of North America and Canada.

But then again why not? I don't think you can get a Travelpower in non-centre tapped. As you can see from ISO13297 there is no reason not to have centre tapped. It is cheaper to make I'm sure, but so what? There is no additional requirement for centre tapped systems on a boat - you need double pole RCD/MCB/RCBO anyway.