Genny dilemma

[Marvo]

Hopefully he can get a refund?

 

[Richard Burns]

Hopefully he can get a refund?

From Ebay or China?!

Certainly the one above seems a better bet, I assume the customer does not need three phase supply.
Does it say anything about the voltage stabilisation, I assume because it is designed as a backup generator it would be suitable but can't see anything on a quick glance, probably in the manual.

 

[D Skelton]

From Ebay or China?!

Certainly the one above seems a better bet, I assume the customer does not need three phase supply.
Does it say anything about the voltage stabilisation, I assume because it is designed as a backup generator it would be suitable but can't see anything on a quick glance, probably in the manual.

Yeah, it comes with AVR as standard. No need for TP supply.

 

[Engineer54]

The EVOPOWER set looks to be the far better bet, it'll probably have a far better AVR and other components than the £300 jobby too. No harm in asking this Generator supply company their recommendations as far as earthing provision to this set. I wouldn't mind betting that they too start talking about N-E connections at the plug top as well though!! Just don't have of it though. The earth connection on the control panel faceplate will be for touch/static voltage only.

What type of C/O switch are you going for, MTS or ATS?? Me i always recommend ATS, but it is the more expensive option. I suppose it depends on how simple you/customer wants the system to be and how accessible the system is going to be, once located in place etc...

 

[D Skelton]

The genny will be located in an outhouse about 15m away from the main property. I've only specced MTS as power cuts are very infrequent but when they do happen they happen for days.

 

[GLENNSPARK]

Yeah, regardless of regs, bonding N+E in the plug especially doesn't feel right to me. It also leaves the possibility that another lead could be used in future that doesn't have the link.

it dont feel rite caus it aint rite...

what you will have created is a TN-C...not allowed in the UK...

 

[D Skelton]

TN-C-S PNB isn't it Glenn? Still, I'm pretty sure we shouldn't be creating this sort of supply!

 

[D Skelton]

Thinking about it, are we even doing that?? To do so would assume that a generator is the same as a DNO supply, which in every case will always have their star point referenced to earth. With this link removed it doesn't change the supply type does it, it just becomes dangerous. A generator provides an electrically seperate supply, linking the neutral to earth to not only reference to true ground but to provide a TN-S supply of sorts doesn't technically create a TN-C-S because the supply type doesn not conform with the norm anyway? That's my thinking. It still feels wrong though to bodge the N-E at the plug rather than in the genny.

 

[GLENNSPARK]

TN-C-S PNB isn't it Glenn? Still, I'm pretty sure we shouldn't be creating this sort of supply!

depends where the neutral-earth link is made

 

[plugsandsparks]

Safety Information It looks like the manufacturer advocates a special "plug" that is connected to the changeover switch which is then plugged into genny. The plug has the NE link. This way they say means the genny can still have a floating earth for pure mobile use. Seams reasonable and sort of covers the issue of the genny being taken away or even sold on.

 

[D Skelton]

The way I see it I can install the link at the genny and label it up accordingly. If it is ever sold then it can be removed, but the fact it is sold as a 'home or office' back up genny tells me that whereever it is used it is going to need a link in place anyway. The thing that worries me is, if that modified plug and cable gets into the wrong hands it could be lethal! People are more likely to consult an electrician if they come into possession of a genny labelled up as 'neutral earth link fitted, consult a qualified electrician before using' than if they come into possession of a seemingly normal but modified extension cable that may or may not have been labelled at some point in the past. I'm gonna have to contact the manufacturer next week regarding their warranty as I wouldn't feel comfortable doing it any other way.

 

[Marvo]

I'd be interested to hear the manufacturers reply.

 

[Engineer54]

It depends how the alternator windings are connected, sometimes it can be a pain converting a floating earth to a referenced earth. As this standby gen-set is going to be permanently located/positioned, it's no longer classed as a mobile/portable unit. As such it should be earth-neutral referenced....

 

[D Skelton]

I can't say how the windings are connected. Annoyingly the only picture I can find seems to be for a US version of the gen set:

 

[Marvo]

I can't say how the windings are connected. Annoyingly the only picture I can find seems to be for a US version of the gen set................

This just highlights the actual problem of which the manufacturers are the single largest contributer. Firstly they mis-market their products, many of them are happy to call a site generator a back-up power solution. Secondly more often than not the design of the generator makes it impossible or very difficult to install it safely. Thirdly trying to find accurate information about the windings and general wiring configuration info you're invariably on a hiding to nowhere.

I'd suggest BY LAW manufacturers should be required to do as follows;

1. A schematic of the wiring of the windings and AVR and supply points on the genny should be on a sticker that's readily visible on the genny itself.

2. Every generator sold should be clearly marked with its intended use.

3. All generators should come with a termination block to allow easy the bonding of the N + E without dismantling the panels or electrical enclosure and without voiding any warranties.

4. Every generator should be sold with an earthing kit consisting of 3 x 2.4m copper earth spikes with couplings, wiring, clamps, spade and a sledgehammer etc.

5. A complete user manual and installation manual should be available for free from the place where the generator is sold. All information therein should be in English that's free from incorrect vocabulary and sentence construction.


Failure to comply with any of the above should result in the manufacturer, the importer and the wholesaler and their immediate families being arrested and prosecuted for attempted murder

 

[rick]

Hello chaps

I understand some of this but not most of it, and it's not something I have ever been asked to do or would undertake - but I would like to understand it a bit more. Any helpful links?

Cheers

 

[D Skelton]

Hello chaps

I understand some of this but not most of it, and it's not something I have ever been asked to do or would undertake - but I would like to understand it a bit more. Any helpful links?

Cheers

Get yourself a copy of Guidance Note 5 and immese yourself in sections 411, 413, 418.3, 551 and 717 of BS 7671

 

[Knobhead]

What CR results do you get when you test the windings to the frame. I do mean CR not IR.

You’ve probably done this but I would be interested in the results.

 

[D Skelton]

What CR results do you get when you test the windings to the frame. I do mean CR not IR.

You’ve probably done this but I would be interested in the results.

Are you referring to a ductor test? If so, why would I need to carry this out? There is no connection whatsoever between winding and frame (on the piece of crap that the customer is now getting rid of).

 

[D Skelton]

Got it in writing from the manufacturer of the genny I have proposed to the customer. Fitting a link between the winding and the chassis does not invalidate the warranty