Victron Inverter

[Johny London]

I have been successfully using my Victron 3000 multiplus inverter for nearly a year now, but have a couple of questions.

I'm unclear about the earthing arrangement - the manual seems to say that it has a relay that takes care of things (my words) but I notice from the previous owner there is a snipped off earth wire and I'm wondering if I should be attaching it somewhere. I have mains hook up, incoming to the unit (only been used once) then the output 230v goes to a consumer unit and onto the ring.

My recent concern comes as as I consider connecting a generator via the ac hook up. (And wondering about its earthing).

Also - I can't find it in the manual but is there a special means for connecting an immersion heater in such a way that it is only supplied with ac if the hook up is active (ie so as not to kill the batteries in five minutes flat!). I intend to use the genny to heat water via 230v as well as charge batteries, to further save engine run time - I don't know how effective it will be with a 1kw element in an 85litre cylinder though.

thank you

[WotEver]

Earthing: The Victron has the option to link N&E when operating as an inverter only. When shore power is available it removes its own link because that is provided by the shore power. A genny should be N-E linked.

Regarding the immersion question, this page should help: http://smartgauge.co.uk/nb_ac_sys.html

Hope that helps. 

Tony

[Alan de Enfield]

To heat 85 litres of water from 15 degrees C to 85 degrees C using a 1kw (1000w) immersion heater, and, assuming no losses or cooling effect during the heating process will take 416 minutes (about 7 hours).

 

Is the size of your generator sufficient to run the immersion heater and your battery charger at the same time ?

Suggest you work on a power factor of 0.65, unless you have the manufacturers figures. (example a 60 amp battery charger MAY require 1200w)

[Johny London]

So, should the earth on the victron be attached to the boat hull too?

I presume a generator would have a switch to select N & E tied together?

[Alan de Enfield]

Just to add  I see from your 'LPG Generator' thread that you are looking at a Kipor or Honda 2000 generator.

Remember that the 'actual continuous' rating of these is only 1600 watts.

To run the inverter and (probably) a fair sized charge you will need to look at a 3000w generator (about 2500 in 'real life')

[Johny London]

12 minutes ago, Alan de Enfield said:

To heat 85 litres of water from 15 degrees C to 85 degrees C using a 1kw (1000w) immersion heater, and, assuming no losses or cooling effect during the heating process will take 416 minutes (about 7 hours).

 

Is the size of your generator sufficient to run the immersion heater and your battery charger at the same time ?

Suggest you work on a power factor of 0.65, unless you have the manufacturers figures. (example a 60 amp battery charger MAY require 1200w)

I was thinking of a 1600/200w generator so it does look a bit tight! But I figured the batteries will only take a certain amount of current - as much as they want and no more - no idea how much that is though. It might be a question of not switching in the immersion until the batteries are a good way through their charge.

On a positive note, the water in the immersion stays hot over night (even though of course some cold gets drawn in every time the hot is used) so it wouldn't be heating from cool unless I'd been away (or used the whole lot in a big bath!). More kind of "topping up" the heat level each day. Or it could be a case of using the engine 50% of the time for the direct water heating effect - so much still to find out so do excuse my ignorance/enthusiasm - I'm sure I will work through all the options and their relative pros and cons until I find what works for me.

Just to add - ultimately I intend to have diesel hot water/central heating with an erberspacer or similar.

Edited May 17, 2017 by Johny London

[Alan de Enfield]

I think that has been said some time ago, but, I would suggest that lifting your your petrol / gas generator onto the bank side & running it for several hours each day will very soon become a real 'PIA'.

Why don't you take the opportunity to build in a 'proper' generator, water cooled, quiet and running of cheap red diesel. You can even programme it to switch on automatically if your battery voltage drops below a preset level. No 'humping' on & off the boat, not having to fetch & carry heavy gas bottles  every week. Make life easy for yourself.

A one off investment cost, balanced by long term gain.

Run your electric blankets, dishwasher, washing machine etc etc and NEVER worry about your batteries.

You will (hopefully) only build a boat once - do it right.

[pearley]

Our 5 year old Victron 3000 comb has a set of terminals alongside the incoming mains terminals to connect an immersion to. Our previous Victron did not. If mains loads on the output side of the inverter are high the charger side will reduce the charge output automatically. It won't do this if the immersion is connected on the input side. I would expect that you would need to bond the neutral to the earth on the generator yourself. I recall that most on CWDF recommend you do this within the hook up lead and that you only use it when connected to the generator and the lead is clearly marked as such. On my built in diesel generator I've connected the bonding link inside the generators control box.

[Johny London]

Alan, I'd love a proper built in genny, but I just can't afford one right now with so many things needing doing. Though I did see one or two interesting looking "projects" (second hand from bt I believe) on ebay after someone on here posted a link for a certain kind of genny. Whether I'd ever get one fitted and working - or indeed if there is room in my nb engine bay, is another matter! Though I did think of using the bow locker(!?).

Pearly - now that was what I was thinking when I went all through my Instructions and installation manual (for the Victron) earlier. There is a completely unused cable gland/connection on the thing so I will investigate further.

Regarding the N/E joining, perhaps I would get a short add on lead (to my 25m) and do the connections in that, thus keeping my options open.

[Rick-n-Jo]

If your Victron has an on/off/charger only switch, then switching to charger only will charge the batteries and pass through mains to your ac circuit, but will not switch the inverter on (and flatten batteries) if the mains or generator drops out.

[mrsmelly]

Why not fit a morco or paloma etc they are to be had quite cheaply and are easy to fit ( must be cos I have done it ) then get it safety checked its a way much better method of getting hot water.

[rusty69]

2 minutes ago, mrsmelly said:

Why not fit a morco or paloma etc they are to be had quite cheaply and are easy to fit ( must be cos I have done it ) then get it safety checked its a way much better method of getting hot water.

Would second that if primary use is for water heating, our Paloma has been brilliant.

[WotEver]

2 hours ago, Johny London said:

So, should the earth on the victron be attached to the boat hull too?

The case should. It's in the instructions to do so. 

Apart from that it should be anyway. You should have shore power to Multiplus, Multiplus to consumer unit, Earth bond from consumer unit to hull. 

[Johny London]

Thanks - I just metered out between earth at a 230v socket and boat hull, they are connected so must be done in the consumer unit, so I'm all good

Regarding the Paloma rout - it does seem to make sense, but it would be yet another thing to think about and do, so for now I will pursue my current lines - maybe when I've been round everything once I'll be better able to consider. Really, the genny is for battery recharge and some heavier electrical use - but as I realised I'll still be running the engine some for hot water I checked the cylinder and it has a 1kw element ready to hook up - just thought I might be able to use that for interim (for more engine saving) though I don't think heating a large quantity of water with electric ever really makes sense. Nice to have a few options though... or it would be!

[Johny London]

On 17/05/2017 at 15:07, pearley said:

Our 5 year old Victron 3000 comb has a set of terminals alongside the incoming mains terminals to connect an immersion to. Our previous Victron did not. If mains loads on the output side of the inverter are high the charger side will reduce the charge output automatically. It won't do this if the immersion is connected on the input side.

I'm just thinking - so this output wont be going through the consumer unit - so no safety with rcd? I presume straight to the element via suitable double pole switch?

[Robbo]

9 minutes ago, Johny London said:

I'm just thinking - so this output wont be going through the consumer unit - so no safety with rcd? I presume straight to the element via suitable double pole switch?

The Victron installation manual shows this connection going to a separate consumer box.

 

Edited May 19, 2017 by Robbo

[WotEver]

An RCD on an immersion heater feed is particularly pertinent. 

[IanD]

Using a generator to heat water using an immersion heater is horribly inefficient -- a diesel gen is typically about 25% efficient, a petrol one less than 20%. When burning the fuel to heat the water directly (Eberspacher/Webasto etc) typically more than 80% of the heat ends up in the water, so 4x more efficient than using a generator -- which means 4x lower fuel cost.

Also a 4kW heater is cheaper than a 2kW generator, and usually quieter, and can be permanently fitted inside the engine compartment...

[Robbo]

13 minutes ago, IanD said:

Using a generator to heat water using an immersion heater is horribly inefficient -- a diesel gen is typically about 25% efficient, a petrol one less than 20%. When burning the fuel to heat the water directly (Eberspacher/Webasto etc) typically more than 80% of the heat ends up in the water, so 4x more efficient than using a generator -- which means 4x lower fuel cost.

Also a 4kW heater is cheaper than a 2kW generator, and usually quieter, and can be permanently fitted inside the engine compartment...

However if your charging batteries, once past bulk stage your are using very little load on the generator, so using a immersion will be better for the generator.  If it's cost efficient in fuel that's another matter but prob not with petrol, a diesel genny is another matter.

[Rick-n-Jo]

There should be no need to run an immersion with a properly built in diesel generator. Ours runs its cooling water through a calorifier coil ( big-141 litres), and well before the batteries are charged we've enough hot water for a bath. Immersion strictly for shore power.

[IanD]

7 hours ago, Rick-n-Jo said:

There should be no need to run an immersion with a properly built in diesel generator. Ours runs its cooling water through a calorifier coil ( big-141 litres), and well before the batteries are charged we've enough hot water for a bath. Immersion strictly for shore power.

Agreed, almost all the fuel energy then goes to heat the water -- but this isn't what the OP was proposing, just electric heating via the immersion heater...

[Johny London]

Getting back to the earthing issue...

I have noticed a feeling of electricity when for example lightly brushing against the aerial of my dab radio. It goes away if you grasp properly, indicating that there is perhaps quite a high floating voltage but with no real current behind it. I just put my multi meter between the aerial and boat chassis, and it actually read a rather puzzling 83v ac.

I already metered out that earth (as in the green and yellow stripey wire found in the plug sockets) is connected to the boat chassis, and I have visually checked and found a good earth bond from the consumer unit to boat chassis. So - not sure if adding one from the inverter earth terminal would be a good or bad idea? I note that Wotever thinks it should be connected.

I'm puzzled as to why this is 83v and if it's indicative of a wiring fault (other than the possible inverter case earthing).

Btw - the rcd trip test button works ok.

[mross]

I'm thinking that if you used a meter with a higher impedance, you might find the voltage to be closer to 230V.  It's probably an induced voltage rather than a wiring fault.  Others will be along but my instinct is that this is odd but not dangerous.

 

[WotEver]

2 hours ago, Johny London said:

I note that Wotever thinks it should be connected

Not exactly...

The output of the inverter should go to the consumer unit. The consumer unit should have a 4mm² earth bond cable from its Earth bus to the boat bonding stud (which should ideally be adjacent to but not concurrent with the DC -ve bond). If it's wired in this way then the Victron chassis is connected to the hull, because it's internally connected to the earth terminal on the unit. 

As suggested, your 83V on the radio aerial is likely to be a stray induced voltage of virtually zero current. 

[Johny London]

Thanks guys - it seems as though everything is correctly connected. And yes of course thinking about it, the meter must be pulling down the voltage. I guess I've kinda been bugged by earthing concerns since the off - or since reading about it in the Victron manual anyway.