Combo Inverter / charger install

TN370

Active Member
Jul 20, 2016
213
Nashville
Boat Info
2001 460 Sundancer
Engines
6CTAs and Westerbeke
Hey folks, I bought myself an combination 2500w inverter / charger. It's the Promariner TruePower Combi. Planning to start install tomorrow but will likely only get it located, mounted, and assess the current wiring on the boat. The plan is to have this unit provide a third source of AC power to the entire panel (along with the shore power and generator options). Wiring the unit to a bank of batteries appears to be straightforward for the DC power into the unit when working as an inverter and DC power back out when charging (unit is auto sensing and switching in this regard). Secondly feeding AC power to the unit appears to be obvious. I plan to just use the circuit and breaker on the AC panel that's currently feeding the old battery charger that I'm removing. After that it gets a little confusing to me.
My first question, for anyone that's willing to give advise, is where I should feed the power provided from the inverter to power the panel? In other words, where do I tie it in? My first thought is to tie into the AC panel wherever the generator ties in. Without having the panel off I assume that's at the two slide breakers. The thought is that this would all me to use the inverter on short term occasions when I don't want to run the generator. But when the generator runs the inverter should auto detect alternate AC power and reverse to charging. The weird thing is that I know I have to be creating a loop on the AC side of the inverter, but I can think of any scenario where it wouldn't be. So why then does the inverter have separate "input" and "output"? Thoughts?
8ce56041623d175d61904fefd1f51429.jpg

9ab952f93b715a2d39594b4e3a1e487e.jpg

953f0d1820dfe45d509305656f2ee735.jpg
 
We have a 2500 Watt inverter. I got a real electrician to put it in. A few things he did. He rewired my panel so the items I use from the inverter are on one side of the boat circuit board. Items are galley, lights, plugs and ice maker. The stove, AC and watermaker are n the other side of the panel. All the inverter/charge are run through a smart controller. I power the inverter with ten 6 volt golf cart batteries. The charger portion of the inverter puts out 120 AMPs at 12 volts.
I have no real idea how it is physically wired but it seems that there are #2 wires from the batteries to the inverter then #8 or 10 to the eclectic panel to a 30 AMP breaker on the same side as the systems the inverter powers. It was put in in 2006.
 
Does the unit you have an auto switch? ie senses when there is either shore power or generator power and then switch from invert to shorepower and back when it's removed? I wired from the panel to the inverter then from the inverter back to the individual items. They are fed as a pass thru when there is either shore or genny running, and then from inverter when nothing else is present. I have a xantrex 3500. I also installed the auto gen start to recharge when my inverter batteries get low.. I have both 220 and 120 circuit. I'm only powering my 120 stuff. i actually did some changes inside the panel which allows for things on both sides to be powered. I bypassed the battery chargers, and all of the 220s stuff. Everything else on my boat works from the inverter... (Microwave, washer/dryer(may remove this), all outlets, tvs, icemakers etc..) i have a pair of 6volt batteries tied in series to power the inverter...
 
The inverter only works when the system is set for generator mode. I had it set up to run the watermaker but there was not enough power as the inrush current for the motor was too great it would trip the inverter breaker. Unit I have is 2500 or 2800 watt. White do not remember the name. The smart panel is set up to start the generator but I do not use it as the generator would go on with the blower off. If the unit would start the blower I would use it. If you run your dryer on the inverter you will draw your batteries down very quickly. The ten 6 volt golf cart batteries take 8 hours to charge at 120 AMPs when they are a 20% remaining. When they set it up it was a stand alone system for charging. I now have it set up so once the 12 volt start batteries are charged the excess power from the alternators will go to the inverter batteries. It is an automatic Blue Sea switch. I left in the 60 AMP converter to charge the start batteries.
 
Does the unit you have an auto switch? ie senses when there is either shore power or generator power and then switch from invert to shorepower and back when it's removed? I wired from the panel to the inverter then from the inverter back to the individual items. They are fed as a pass thru when there is either shore or genny running, and then from inverter when nothing else is present. I have a xantrex 3500. I also installed the auto gen start to recharge when my inverter batteries get low.. I have both 220 and 120 circuit. I'm only powering my 120 stuff. i actually did some changes inside the panel which allows for things on both sides to be powered. I bypassed the battery chargers, and all of the 220s stuff. Everything else on my boat works from the inverter... (Microwave, washer/dryer(may remove this), all outlets, tvs, icemakers etc..) i have a pair of 6volt batteries tied in series to power the inverter...

Pringle, yes the inverter does have an auto switch. When set to "on" it is suppose to sense shore or generator power and pass thru. Without sensing any AC power it should activate the inverter and fees AC power to where ever I have it feed. I guess I'm going to start looking to see how the generator feeds power to the panel. However since I'm placing the inverter in the engine room it would be nice if I could tap the generator feed somewhere in the engine room without having to feed a new 110 to the panel. Hoping someone on here has done so and can weigh-in on that.
I would try to have the inverter feed separate circuits like you have but it's just not worth the extra work in my opinion. The only thing I have to remember not to have on with the inverter is my two hvac units. And the inverter has safety shut offs for overload anyway. So for simplicity I'd like to just find the easiest way to feed the 110 power to the entire panel by tying in somewhere in the engine room if that's reasonable to do. Any more advice is appreciated!
 
I did not install an Inverter/Charger but rather an inverter with an automatic transfer capability. This schematic is how it's wired which is completely seamless regardless if the shore power is on or off or the generator is on or off. One thing that must be done is the neutral (Common) wires for the inverter circuits have to be all on the same terminal strip as the inverter; for example, the Galley Systems circuit was fed from line 2 but I wanted that circuit on the inverter so not only the Hot wire was fed from the inverter the common was required to be relocated to Line 1 common terminal strip which the inverter was using.
 
Last edited:
I can also put together a schematic if you need one, however you might not want to install it into the engine room. I see you have 454s so unless your invert is ignition protected i'd probably look for somewhere inside. As for mine, I pulled a couple of new sets of lines from my panel to the inverter and back. I moved the original lines from the 120 feeds on the breakers to make dedicated for each of my chargers, then connected the pulled lines to the breakers and the buses to feed the 120 items.. Hopefully that makes sense..
 
You might not want to wire the inverter to power your entire AC system. If you accidentally leave a high draw item on, (water heater, AC pump, fridge, etc), you will drain your batteries quickly. One other thing to consider is that if the inverter were to fail, you would probably lose all AC power as shore power would not pass through the failed inverter.
 
My Norcold refrigerator bit the dust and replacement marine AC/DC units are outrageously priced compared to an AC only unit. I've been considering purchasing an inverter and using that with a replacement AC only fridge but uncertain if the inverter can handle the load. Mind you, we don't "camp out" all that often so there will almost always be shore power or the genny running.

Anybody else powering a standard fridge using an inverter?
 
My Norcold refrigerator bit the dust and replacement marine AC/DC units are outrageously priced compared to an AC only unit. I've been considering purchasing an inverter and using that with a replacement AC only fridge but uncertain if the inverter can handle the load. Mind you, we don't "camp out" all that often so there will almost always be shore power or the genny running.

Anybody else powering a standard fridge using an inverter?

BlkBird, Most of our larger boats have AC only appliances, which means we either run our gennys all the time, or have inverters. My inverter will run my AC only refrigerator, AC only freezer with Icemaker, Wine chiller, and Second bridge AC only refrigerator for approximately 8 hours without need to run the genny. I then get my low battery capacity alarm and my generator will automatically startup and charge things back up. So yes, we "Camp out" and it does work.. Most of the time, when i shutdown the genny, is mainly late at night till early am.. hope that helps.. BTW your refrigerator doesnt run constantly either.
 
What model inverter Is used?
And do you run off a separate power bank of batteries?
 
I had a fellow boater at the marina show me his setup and it seems to work well. I think I'm going to mimic it. I'm going to leave the engine batteries and 3-bank charger that are currently in the boat as-is. New inverter/charger will be a separate system. Going to have the "120V IN" fed from a new breaker on the main panel. Will feed the "120V OUT" directly to the generator before it feeds to the panel. And "12V OUT" will feed a battery bank of 2 or 3 new batteries.
The plan is with the generator off the inverter will feed any needed 120V that the generator would normally serve (some longer than others). The inverter has an audible alarm for low batteries. With the generator on (upon low battery) the battery bank will recharge by the generator feeding the panel to the breaker that's feeding the 120V IN on the inverter.
This setup is intended to allow us to use 110V fans, small ceramic heaters, TVs, etc for a few hours when we anchor or raft up with other boats. All without generator noise and fuel burn. So the question now is, what batteries? I'm aiming to have approx 800ah.
 
I had a fellow boater at the marina show me his setup and it seems to work well. I think I'm going to mimic it. I'm going to leave the engine batteries and 3-bank charger that are currently in the boat as-is. New inverter/charger will be a separate system. Going to have the "120V IN" fed from a new breaker on the main panel. Will feed the "120V OUT" directly to the generator before it feeds to the panel. And "12V OUT" will feed a battery bank of 2 or 3 new batteries.
The plan is with the generator off the inverter will feed any needed 120V that the generator would normally serve (some longer than others). The inverter has an audible alarm for low batteries. With the generator on (upon low battery) the battery bank will recharge by the generator feeding the panel to the breaker that's feeding the 120V IN on the inverter.
This setup is intended to allow us to use 110V fans, small ceramic heaters, TVs, etc for a few hours when we anchor or raft up with other boats. All without generator noise and fuel burn. So the question now is, what batteries? I'm aiming to have approx 800ah.

I would have a safety concern as well as a concern with your generator's rectifier circuit as you will be "back feeding" the generator when on shore power or on inverter power. Also this configuration will not be NEC or ABYC compliant due to the potential loads on the system. Circuit breakers are there for fault current protection not to ensure you are not over-taxing the inverter by too many circuits.

A much better, safer, and fully automatic arrangement is to:
1 - feed the inverter "input" or line power from a new circuit breaker in your AC panel (as you say). Same as I have it in my schematic on a previous post. This will both provide either generator power or shore power through the inverter's transfer switch when either of them are connected. As you can see in my schematic I installed a new breaker (the red are new or changed wiring).

2 - feed the inverter "output" or load power to the circuits you want to feed in your AC panel which are all after your boat's generator/shore power transfer switches. Disconnect those circuits from their current power and uniquely connect the inverter to them.

In this arrangement the inverter will provide power to the connected circuits by generator, shore power, or inverter completely automatically and safely.
I can also post some pictures on how I connected the inverter to the unique circuits in the AC power panel.

As far as batteries and a point of departure - My inverter on the 400DA is smaller and I run it off three 900AH AGM batteries which will operate the boat's entertainment systems in the evening and morning as well as a couple of pots of coffee in the morning that's about it. Remember a 500 watt demand at 120 VAC is 5000 watts or about 420 amps from the batteries plus the inverter's efficiency rating of around 90% which puts the demand on the batteries at around 460 amps which in my case would only give about 1.5 hours maximum. Remember also that as you don't have a true sine wave inverter anything you power that is an electric motor is inefficient and will draw about 20% more than the motor's rating. Your "small" quartz heaters will definitely be demanding on the batteries.
You haven't illustrated you math on sizing but based upon your post you will need quite a large bank of batteries which there probably isn't enough room to install on a 370DA.
 
Last edited:
I would have a safety concern as well as a concern with your generator's rectifier circuit as you will be "back feeding" the generator when on shore power or on inverter power. Also this configuration will not be NEC or ABYC compliant due to the potential loads on the system. Circuit breakers are there for fault current protection not to ensure you are not over-taxing the inverter by too many circuits.

A much better, safer, and fully automatic arrangement is to:
1 - feed the inverter "input" or line power from a new circuit breaker in your AC panel (as you say). Same as I have it in my schematic on a previous post. This will both provide either generator power or shore power through the inverter's transfer switch when either of them are connected. As you can see in my schematic I installed a new breaker (the red are new or changed wiring).

2 - feed the inverter "output" or load power to the circuits you want to feed in your AC panel which are all after your boat's generator/shore power transfer switches. Disconnect those circuits from their current power and uniquely connect the inverter to them.

In this arrangement the inverter will provide power to the connected circuits by generator, shore power, or inverter completely automatically and safely.
I can also post some pictures on how I connected the inverter to the unique circuits in the AC power panel.

As far as batteries and a point of departure - My inverter on the 400DA is smaller and I run it off three 900AH AGM batteries which will operate the boat's entertainment systems in the evening and morning as well as a couple of pots of coffee in the morning that's about it. Remember a 500 watt demand at 120 VAC is 5000 watts or about 420 amps from the batteries plus the inverter's efficiency rating of around 90% which puts the demand on the batteries at around 460 amps which in my case would only give about 1.5 hours maximum. Remember also that as you don't have a true sine wave inverter anything you power that is an electric motor is inefficient and will draw about 20% more than the motor's rating. Your "small" quartz heaters will definitely be demanding on the batteries.
You haven't illustrated you math on sizing but based upon your post you will need quite a large bank of batteries which there probably isn't enough room to install on a 370DA.

Thanks for the feedback. I was hoping for some. Yes, I can see some concern with with back-feeding 110V from the inverter to the generator when on shore power.
I like how you described your setup but I have some concern with altering the boats factory wiring that much. That setup relies on the inverters internal switching to pass thru all power to the altered circuits when the generator is not running. That's most likely how the manufacture of the invert intended it to be wired but there's the "what ifs". I guess if the inverter ever failed and I couldn't replace it with one that functions the same way I would always tie the 110V IN and OUT together and it would be back at factory function, right?
 
Isolating the circuits that you want to power with the inverter is the safest way to go. A marine electrician should be able to easily isolate those circuits at the back of your electrical panel and connect the inverter AC output. Any setup that can potentially allow for two sources of AC power on one circuit is dangerous.

Depending on the low battery alarm on the inverter will shorten the life of your batteries. The low battery alarm is set at 10.5v. 10.5 volts is pretty much a completely discharged battery. A couple of complete discharges can kill a battery.

What will be the battery setup connected to the inverter?
 
What model inverter Is used?
And do you run off a separate power bank of batteries?

Hi Christopher,

Noticed you are in Atlanta as am I. I have a Xantrex 3024 Charger/Inverter installed on my 550DA. Used Bow Thruster Batteries (2 x 8D's) for shared service. Send me a PM if you want to take a look at the install. Boat is at Bald Ridge.

Brett
 
Thanks for the feedback. I was hoping for some. Yes, I can see some concern with with back-feeding 110V from the inverter to the generator when on shore power.
I like how you described your setup but I have some concern with altering the boats factory wiring that much. That setup relies on the inverters internal switching to pass thru all power to the altered circuits when the generator is not running. That's most likely how the manufacture of the invert intended it to be wired but there's the "what ifs". I guess if the inverter ever failed and I couldn't replace it with one that functions the same way I would always tie the 110V IN and OUT together and it would be back at factory function, right?

As it ends up there is no need to alter circuits, at least on the 400DA. Simply added a new breaker in the accessory empty breaker location (bottom left breaker in picture) then moved the copper buss bars off the breakers that needed to be tied into the inverter and then tied the inverter output wiring to those breakers (top two left and top one right in picture). Everything can easily be returned to original. It was very simple.
Lastly, inverters with automatic transfer switching integrated are very common so if yours went south many others are available. BTW the failed mode is bypass.
 
Last edited:

Forum statistics

Threads
112,950
Messages
1,422,861
Members
60,932
Latest member
juliediane
Back
Top