Inverter Installation Question

[bobfnbw]

Hi, installing the victron inverter charger. 3000 watt 120v 50 amps with a 120 amp charger.

The install manual on the ac circuit has this :

4.3 Connection of the AC cabling
The MultiPlus is a safety class I product (supplied with a ground
terminal for safety purposes). Its AC input and/or output terminals
and/or grounding point on the outside of the product must be
provided with an uninterruptible grounding point for safety
purposes.
The MultiPlus is provided with a ground relay (relay H, see appendix B)
that automatically connects the Neutral output to the chassis if no
external AC supply is available. If an external AC supply is provided,
the ground relay H will open before the input safety relay closes. This
ensures the correct operation of an earth leakage circuit breaker that is
connected to the output.
In a fixed installation, an uninterruptable grounding can be secured by
means of the grounding wire of the AC input. Otherwise the casing
must be grounded.
In a mobile installation (for example, with a shore current plug),
interrupting the shore connection will simultaneously disconnect the
grounding connection. In that case, the casing must be connected to
the chassis (of the vehicle) or to the hull or grounding plate (of the
boat).
In case of a boat, direct connection to the shore ground is not
recommended because of potential galvanic corrosion. The solution to
this is using an isolation transformer.
The terminal blocks can be found on the printed circuit board, see appendix A. The
shore or mains cable must be connected to the MultiPlus with the aid of a three-wire
cable.
- The AC input cable can be connected to the terminal block “AC–in”.
The AC input must be protected by a fuse or magnetic circuit breaker rated at
50A or less, and cable cross-section must be sized accordingly. If the input AC
supply is rated at a lower value, the fuse or magnetic circuit breaker should be down
sized accordingly.
- The AC output cable can be connected directly to the terminal block "AC-out".
With its PowerAssist feature the MultiPlus can add up to 5kVA (that is
3000 / 120 = 25A) to the output during periods of peak power requirement. Together
with a maximum input current of 50A this means that the output can supply up to
50 + 25 = 75A. Not sure if I would need this... don't have a genset yet and the heavy loads are not connected to the inverter.

An earth leakage circuit breaker and a fuse or circuit breaker rated to support
the expected load must be included in series with the output, and cable crosssection
must be sized accordingly. The maximum rating of the fuse or circuit
breaker is 75A.

Not sure I understand this.
The shore power is a 120/240v 50 amp with a 6 awg wire to a 50 amp BSS 120/240 v breaker. This one hot leg then goes to the inverter charger, and one to the non inverter loads, which are 2 air conditioners and a hot water heater.
From the inverter, it goes to a second 4 breaker panel, with the inverter loads which are the port, starboard and galley outlets. 4 circuits with 15 amp
breakers for a total of 70 amps. Is that what the install is refering to?

Also what size wire for the AC side should I use for this install. I was going to use 10/3. The distance from the inverter to the charger is about 10 feet one way

Thanks for the input. I realize that this install is my responsibility, and I take full responsibility for installing it. Just would like to help on this one.
Thanks.
Bob

[bobfnbw]

The earth leakage circuit breaker... I guess thats a GFCI wired in series on the loads? If that is it, then no problem there, all 4 circuits will have Marinco GFCI breakers on the first
outlet. Was going to use BSS GFCI breakers, but to expensive and takes up to much room.

[btrayfors]

Bob,

You said, "The distance from the inverter to the charger is about 10 feet one way". I assume you meant the distance from the inverter/charger to the panel is 10 feet one way.

For 50A circuits (with 75A potential for momentary loads), you need AWG6 cabling, just like from the shore cord.

Yes, your interpretation of the GFCI is correct, IMO.

Love my MultiPlus.

Bill

[bobfnbw]

Yes, Sorry Bill, I meant that from the inverter charger to the Panel.

I will use AWG 6 gauge for it. Appreciate the input.

Did you use the voltage sense capability, and if so, how did you wire it. The unit only comes with a temp sense wire. Which has a polarity to it, but the connection seems to be to just a single lug terminal.... why the polarity then?
thanks,

Bob

[btrayfors]

Bob,

Many temp sensors use inexpensive thermistors. These little devices change their characteristic resistance with temperature. Resistance drops as temperature increases. You can then get a pretty good fix on the temperature by measuring the resistance across the thermistor.

The Victron temp sensor is most likely this type. The single lug is just a convenient way to connect to the battery post, but the thermistor circuit is inside the lug. The two wires go to the measurement circuit inside the MultiPlus.

Bill

[Zednotzee]

Have a look at this thread too. I believe Nick (aka s/v Jedi) has already installed one of these, so he may be able to shed more light on the issue.

http://www.cruisersforum.com/forums/...tem-29667.html

[sailvayu]

Also just a reminder be sure your inverter loads are on a separate neutral buss separate from the shore neutral.

Fair winds

Wayne Canning, AMS
projectboatzen.com

[David M]

I am inclined to say you should consider hiring a professional who knows the ABYC standards inside and out. I do not know your experience with AC and DC marine electronics, but you are asking a few pretty basic questions like which wire gauge to use.

At the least, consult with a professional before the installation and then have him look at the finished installation. This will insure that you have made a safe and reliable installation and do not have to go back and re-do your work. It will also give you some piece of mind.

[CharlieJ]

Also just a reminder be sure your inverter loads are on a separate neutral buss separate from the shore neutral.

Wayne-I do not understand your recommendation. A single leg of 240 VAC/50 A split phase shore power is input to the I/C, and if it is qualified (voltage and frequency) then it is passed through the inverter to the sub panel. Since he has 240 VAC/50 A split phase, L1 and N will pass through the I/C and L2 will by-pass the IC, picking up N on the output side of the I/C.

Bob-What is the model number of the Victron you are installing? If you could, please provide all of the numbers as the Victron model numbering scheme is a bit difficult.
(The Victron site is down right now and the only manual I have downloaded is the 12/3000/120-50/230-240)

[bobfnbw]

Thanks all for the input.
I learn as I go. As for hiring a marine electrician... I don't mean to sound pig headed but in my town, I don't have a lot of confidence in that. The local here charged me 5000 usd to remove and reinstall my engine, and 12,000 usd to replace 13 thru hulls, a cutless bearing...and a bottom job. Needless to say, I felt taken to the cleaners.
I have wired many houses, and understand that it is different than a house, yet it's not rocket science. But I don't want to mess up, so I ask for help here. And as you can see, I put in the disclaimer that I am sole responsible for what I do or do not do.
anyway the victron unit I have is the VICPMP123021100W, purchased and located here..
http://shop.pkys.com/victronmultiplus123000120-50120vwhitevebusinvertercharger.aspx


Charlie, the way I planned to wire this is the 4 wire 6AWG from the shore power connection goes to a Blue sea 50 amp 120/240 volt breaker. I am splitting the power legs, with one going to the inverter/charger and one going to the heavy a/c loads which are 1 12K btu ac, 1 10K btu ac, and a indel 750 watt hot water heater. the other breaker is for future use. The other power goes to the inverter/charger then back to the house load, which will power 4 15 amp circuits. All these will have GFCI outlets on the first outlet of the leg. 5 outlets on the stbd side for one circuit. 1 on the microwave. 1 for a induction cooktop. and the last 15 amp circuit is 5 outlets on the port side. All is with 10/3 ancor wire.
On the dc side, from the main bus, 2 2/0 cables go thru a 400 amp Class T fuse to the battery in on the inverter, and 2 2/0 cables go from the main ground buss to the negitive side of the inverter.

At this time, I do not have a Isolation transformer, but plan on adding one in the coming years. I had a galvanic isolator but did not rewire it on this rewire. Do not plan on adding one. All thru hulls are not forespar marelon. The shaft and rudder are not bonded. The keel is encapsulated.
I do not have a genset of any kind yet, but plan on adding one, either a diesel built in 5kw or dual honda 2000 watt gas generators at some time in the future.

Why does the neutral need seperate buses? Since they will ultimately be connected back to the neutral side of the shore power connection... what is the difference? Just trying to learn here.

The case is connected with a 6 AWG wire to the neg bus.

Bob

[bobfnbw]

OK, found this thread, http://www.cruisersforum.com/forums/...ing-26104.html
I think I understand the reasons for the dual neutral bus now. Still only one AC ground bus though, right?

Bob

[Zanshin]

Bob - I hope you enjoy your Victron, I have the next unit up in 220V and think it was a worthwhile investment - charging my batteries quicker and supplying that extra "oomph" of power when I fire up the watermaker off the genset. The inverter is used for a high-drain coffee machine and low-drain elements such as now with the power supply to the notebook I'm posting from. If you do intend on using it with low powered sources such as a genset then the external control panel where you can adjust the charging rate is very useful. I posted some pictures at Victron Inverter

[sailvayu]

Bob yes the grounds are connected.

Charlie I am not sure I understand why you would not use a separate neutral with a split 240 system? And I am asking because I really would like to know. I have always seen it separate even on 240 volt systems. I looked in ABYC this morning but do not see any mention of it being different with 240. I would think if you were running inverter loads alone you are a 120 VAC system and need to be wired like that. If you combine them even on a 240 VAC system you can still leak back to the non Inverter side in the event of a fault. So if I am wrong here I would like to know.

Thanks

Wayne Canning, AMS
projectboatzen.com

[bobfnbw]

Originally Posted by Zanshin

Bob - I hope you enjoy your Victron, I have the next unit up in 220V and think it was a worthwhile investment - charging my batteries quicker and supplying that extra "oomph" of power when I fire up the watermaker off the genset. The inverter is used for a high-drain coffee machine and low-drain elements such as now with the power supply to the notebook I'm posting from. If you do intend on using it with low powered sources such as a genset then the external control panel where you can adjust the charging rate is very useful. I posted some pictures at Victron Inverter

Love your website, and the name as well.

thanks for posting it.

Bob

[CharlieJ]

Wayne/Bob-A vessel with separate 30 A shore power services may have the two outlets on the dock derived from separate sources. In this case, there are separate neutral busses on the vessel and the neutrals from the vessel loads are maintained on the bus that corresponds with the hot wire that serves that load.
See ABYC July 2009-2010: E11.17.1.3

Different animal with 50 A/250 VAC. With a single shore power service, only one neutral comes aboard from which you can derive 240 VAC (no N); and two legs of 120 VAC, each utilizing the same N. See ABYC July 2009-2010: E11.17.2.2.

With an I/C in the mix, things get a bit more interesting as the I/C bonds the N and G internally when the I/C is inverting. And this is why I need to change my recommendation in Post #9.

L1 and N are input into the I/C and pass through to feed the I/C load panel when on shore power. N and G are bonded where the power is derived, probably a transformer on at the entrance to the marina. When there is no qualified power available, the I/C starts to invert and N and G are bonded inside the I/C as the I/C is now the source of power for that load center. All N's from the loads supplied by this load center must be tied to the N provided by the I/C so that there bonding/non-bonding is controlled by the I/C.

Meanwhile, L2 and N have to supply the non I/C loads. My advice in Post #9 did not take into account the internal bonding that occurs when the I/C is inverting. The non-I/C panelboard should be fed from upstream of the I/C through an appropriate double pole circuit breaker. All the N's from the loads served by this panelboard need to be tied to this N bus as it is bonded at the marina transformer and is not subject to what the I/C is doing.

So, Wayne is correct when there is an I/C is involved using 50A/250V shore power in the manner described. There are two N busses, one served by the I/C and one served by the transformer at the marina entrance.

Bob-
I will look at the techman later. One tip for installing the Victron is to install short pigtails while you have the unit on the bench. Lead the pigtails out to a box with a 50A terminal strip for the AC in and out and to a 20A terminal strip for the voltage and temperature sense. I have found that is much, much easier installing AWG 6 down hand then when the unit is mounted and you have the added advantage of an easy place to check voltages without removing the six panel screws!

Hope this helps and sorry for the confusion in Post #9...it was late.

Charlie