Generator to mains socket?

[Bilgemonkey]

I have a 3.8Kva generator and was wondering if it is possible to use it with a lead with 2 13A plugs on either end and then just feed it straight into a 230 socket on the mains ring of the boat. I have a Victron inverter, would this do any damage to it? I have a shoreline that plugs into the inverter at the front of the boat in the engine bay but this doesn't seem to work anymore and means running the shoreline the whole length of the boat to get to the generator which is a bit big to lug around. Thanks for any help.

[dor]

I've done this in a house, after isolating the mains so my genny wasn't trying to feed the national grid, but I wouldn't like to say what it would do to your victron.

 

I would get the shoreline socket fixed and/or set up the genny with a proper connection.

 

You say the shoreline plugs into the inverter - I don't think you really mean that. Do you have a changeover switch to select inverter or shoreline. If so you should be able to isolate the inverter from the ringmain so your double plug would work - but I would see that as just a temporary arrangement.

[NB Willawaw]

I really wouldn't recommend doing that for a whole host of reasons.

It really doesn't make sense to cut corners with mains electricity.

If you do what you have suggested, what protection will there be in that circuit ?

[ChrisPy]

it can't be too difficult to establish why your shoreline connection isn't working.

the fault may be related to the mains fault protection system, which is safety-critical.

I agree, you should not take short-cuts of the type you suggested.

 

.... oh, and having 240V on the pins of a loose plug is close to suicidal.

[bottle]

2 13A plugs on either end

 

If you actually mean plugs on both ends do not do it, it will be leathal.

 

240 electrics must not be 'played' with, it will kill

 

Wiring for a boat with invertor and landline is simple, a changeover switch will be required, the 240v sockets wired back to a distribution/fusebox.

 

The distibution/fusebox will be connected to the changeover switch this will be supplied by the invertor and the landline, separate connections.

 

A plug must never be 'live'.

 

Edit: Chris posted whilst I was typing and to sort typo.

Edited November 24, 2007 by bottle

[Bilgemonkey]

Thanks guys, looks like I won't bother trying this, just wondered if it was sensible but seems not. I think you are right dor, it doesn't plug into the inverter, will have to have a closer look. I have only used the generator with the shore line once and it worked fine but since it hasn't worked. The problem is the shoreline isn't long enough to reach where the generator is without moving the generator on the roof which isn't practical. The shoreline socket is at the front of the boat where the engine is and it seems a bit silly have it trailing the length of the boat (60 feet) if I got an extension. Anyway, first things first, getting the generator working the 230 in the first place! Thanks again people.

 

[edit] Also I have an extension cable anyway, will run this from the generator if needed for now, a lot safer me thinks.

Edited November 24, 2007 by Bilgemonkey

[John Orentas]

Hi Bilgy.

 

Having a plug and socket arrangement to select mains or generator is probably the safest and most failsafe way to do the job but not in the way you intend (or as I interpreted it) what you should do is install a 'fixed plug' in the boat and connect to it the mains or generator supply, doing it this way there is virtually impossible to connect things wrongly.

 

Most people on the forum (but not me) use a selector switch system, but this is not without it's dangers, if you where to do this in an industrial environment you would need to take extra precautions mainly that the selector was designed and manufactured for the job, notably the electrical contacts must be of the 'break before make type' and that they 'force break'.. Does the average chandler or marine supplier make this distinction ?

[blackrose]

Most people on the forum (but not me) use a selector switch system, but this is not without it's dangers, if you where to do this in an industrial environment you would need to take extra precautions mainly that the selector was designed and manufactured for the job, notably the electrical contacts must be of the 'break before make type' and that they 'force break'.. Does the average chandler or marine supplier make this distinction ?

 

Aren't all selector switches made to the recommened safety standards?

[John Orentas]

Aren't all selector switches made to the recommened safety standards?

 

 

No, some types are made to make before break, but for most applications it is not critical.. Most of course rely on some some form of spring mechanism to open the contacts, if the contacts weld together, the others may still close.

 

Types 'made for purpose' will have contacts which are forced apart by the action of the lever mechanism and one set of contacts cannot close until the others have mechanically separated.

 

Also an 'Isolator' need not be rated for on load switching.

Edited November 24, 2007 by John Orentas

[Bilgemonkey]

Hi Bilgy.

 

Having a plug and socket arrangement to select mains or generator is probably the safest and most failsafe way to do the job but not in the way you intend (or as I interpreted it) what you should do is install a 'fixed plug' in the boat and connect to it the mains or generator supply, doing it this way there is virtually impossible to connect things wrongly.

 

Most people on the forum (but not me) use a selector switch system, but this is not without it's dangers, if you where to do this in an industrial environment you would need to take extra precautions mainly that the selector was designed and manufactured for the job, notably the electrical contacts must be of the 'break before make type' and that they 'force break'.. Does the average chandler or marine supplier make this distinction ?

 

The boat already has a shoreline socket in the engine bay at the front if that is what you mean, and as far as I can tell already has a switch. The boat has a Victron inverter with a remote panel in the bedroom which has a switch for inverter on, off and charger only (quite common I assume) as well as a control knob labeled shoreline limiter (whats this for exactly?). I have successfully run the generator through the shoreline socket and the remote panel LED's for float and power on light up as I assume they are supposed to.

Recently I had problems running the engine to charge the batteries (turns out the diesel filter was blocked) so once again ran the generator through the shoreline but this time nothing happened, no lights on the remote panel etc.

At the moment I'm assuming there's a problem with the shoreline, maybe a fuse or the in-line meter but could be wrong. By the way I'm running a cheap 3.8 Kva Biggs & Stratton B&Q jobby at the moment.

Thanks for any help on this, still a novice when it comes to things like this and it's very handy to have advice like this so I don't do anything to stupid.

[chris w]

Note also that if you use a gennie, you need to connect its earth and neutral together and connect the boat earth to the gennie earth too otherwise any RCD trips you have on-board won't function in the event of an earth fault. This could lead to a potentially lethal situation.

 

Chris

[Bilgemonkey]

Didn't know that either chris, thanks for the advice.

[rjasmith]

Bilgemonkey,

 

Ref your post#10 it sounds like you have a Victron Phoenix Multi Plus which is a combination charger/inverter not just an inverter. It has the facility of synchronising its inverter output to the AC coming in from the shore line (or a generator connected instead into the shore line socket. Nowhere else!!). The "shore line limiter" control can then be set to the maximum current level available from the shore line (or generator). If the AC load in the boat remains below the set limit, the Victron will use the surplus power to charge the batteries. If the load goes above the limit for a short time the Victron will switch to take power from the batteries and add its inverter output to the AC load so that the shoreline or generator does not have to contribute more than the set level. When the load peak has passed, the Victron goes back to charging again.

 

Sounds like you haven't got the handbook for your Victron - they can easily be downloaded from the Victron website at www.victronenergy.com/

 

Also on the site is their book "Electricity on Board" which is free to download and will give you a lot of background if you want all the technical stuff!

 

Just to add a further warning about plugging a generator in to the 13A sockets - remember two independent sources of AC can't just be connected in parallel - they have to be synchronised together to do this (as all the power stations on the Nat Grid are!). The Victron contains all the electronic bits to do this if it is a Multi Plus and will only do it if the external power is connected in the right way!

 

Hope this helps

 

Richard

[Bilgemonkey]

Thanks rjasmith, that is exactly what I have and you're right, I don't have the handbook, will download it.

So with this setup is it ok to plug the generator into the shoreline without doing what chris w said about wiring the earth and neutral together etc or do I still need to do this.

Months ago I had the engine running as well as the generator so we could run the washing machine and everything worked fine but now this no longer works. As I said before I suspect the shoreline itself is the problem so will have to check it and report back If I get it working.

Thanks for the help again people, much appreciated.

 

[edit]

 

Unfortunately all the manuals seems to be offline at the moment, get a 404 not found. Guess I'll have to check back there another time.

Edited November 25, 2007 by Bilgemonkey

[pagan witch]

We have one side of our boat fed from shoreline via MCB etc and to feed the other side we plug what amounts to a permanently installed extension lead with sockets where we need them that has a normal mains plug on the end.

 

With this arrangement we can choose where the mains comes from down this leg :-

 

Either plug into the shore line side to get shore main

Or by unplugging it and putting it into the inverter we have inverter power down the line

Lastly by putting the same plug into a double socket hard wired into the electrical cupboard fed from the generator (its' only wired up output).

 

This is foolproof even to a talented fool like me and passed BSC with a similar comment being made about how it was impossioble for anyone to screw it up.

 

OK - so it isn't auto switching or owt fancy but reliable - totally

[chris w]

So with this setup is it ok to plug the generator into the shoreline without doing what chris w said about wiring the earth and neutral together etc or do I still need to do this.

 

YES you do....... earthing the gennie is a separate issue to the Victron load sharing issue and joning the earth and neutral together is to ensure the RCDs trip in the event of a fault. Otherwise you have a floating supply. Victron themselves talk about the importance of correct grounding in your unit's handbook.

 

Chris

Edited November 25, 2007 by chris w

[Bilgemonkey]

Thanks again Chris.

Got the manuals and the PDF's through a different link on their site and will have a good read.

[DHutch]

With a 3.8kva at 240vac is 16amps, near as.

 

So you could use standard 16amp ceeform shorline equipment between then generator and boat, with the suitable switches/plugs/sockets as required, fused as nessary.

- Feeding the gennerator into the input of the victoron inplace of the mains/grid supply. Eather with a change over switch, or simply by pluging the generator into the socket intended for the mains hookup.

 

Bearing in mind as mentioned, the need for approprate earthing and protection. And also that the rcd regulations on permantently installed generators, if that is the route you plan to go down.

 

 

But yes, placing a female plug on each end of a 240v lead and 'backfeeding' it into a socket/outlet on the boat is very a bad idea.

- Simularly, using two leads to share the current output of the generator is not good practice, and potentially also unsafe if not setup in the correct fashion.

 

 

Daniel