Dangerous Inverter Setup?

Discussion in 'Electrical Stuff' started by Ky Tundra, Sep 6, 2017.

  1. Ky Tundra

    Ky Tundra Member

    46
    Sep 5, 2017
    Kentucky
    1989 Sundancer 340
    Twin 454 Mercruisers with v-drives
    Just bought an 89 Sundancer 340. Previous owner installed a 2000W inverter in the bilge on the starboard side. From the little bit of research I've done the installation has multiple problems, please correct me if I'm wrong. It shouldn't be installed in the bilge with gas engines. It shouldn't be installed right above the batteries . And he rigged up an extension cord with two male ends, presumably to backfeed the system. He did use a heavy gauge wire with a fuse to connect to battery, for what its worth.

    My questions:
    Is it safe to have it in the bilge? Maybe if you run the blower when its being used? Not sure how its different than the spark created when firing up the engines.

    Is there any scenario that the backfeed setup is safe?

    Is it OK in a compartment with the batteries since they are AGM?

    I'm not turning it on until I work out all of the details.

    Thanks for any advice.
     
  2. Little Ducky

    Little Ducky Well-Known Member

    Jun 5, 2017
    Chattanooga TN/Dickson TN
    1998 SeaRay 290 Sundancer
    Twin EFI 5.0L w/Alpha 1 drives
    Yikes.

    I'm not a electrician but just the sound of that makes me shiver.

    What was their end game? Did they do all that just to run 120v appliances?
     
  3. Ky Tundra

    Ky Tundra Member

    46
    Sep 5, 2017
    Kentucky
    1989 Sundancer 340
    Twin 454 Mercruisers with v-drives
    I'm not sure what the end game was, but I assume that was the goal. I'm not sure what else an inverter on a boat is used for. You'd need quite a bank of batteries and large inverter to run anything larger. Or am I missing something? I've never had one. The thing looks brand new and I'd like to take advantage of it if I can figure out a safe and practical way to use it.
     
  4. Bt Doctur

    Bt Doctur Well-Known Member

    Aug 21, 2010
    New Jersey
    Ex SRV 240 Weekender twin
    in between
    pictures would be helpful.But I would put it above decks, run atleast a 1/0 or 2/0 to the batteries. Just plug in what you need to run on AC
     
  5. ttmott

    ttmott Well-Known Member

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Is there any scenario that the backfeed setup is safe?
    Yes but not this way; there needs to be a transfer switch so the circuits that are to be connected are either on boat's AC system or the inverter; there cannot be a situation where through human error both power sources are energizing the circuit(s). And double male cords are a definite no-no.

    Is it OK in a compartment with the batteries since they are AGM?
    No issues here with the batteries but unless the inverter is rated for hazardous locations it cannot be in with gasoline systems.
     
  6. northern

    northern Well-Known Member

    Jan 17, 2007
    West coast Vancouver to Alaska
    380 Aft Cabin 1989 GPS and Charts by Nobeltec
    Twin 454 strait shaft
    Our is in the engine room. It was installed by a real marine electrician and inspected by a real marine electrical inspector. You may want to have your system looked at by a real electrician and inspected by a qualified inspector. We have had ours in service since 2006 and have not had any problems. Other real electricians have worked on the boat since then and they have found no fault with the system. Yours may be fine or could be a bad thing. You do not know until a quailed person looks at it.
     
  7. wayne0

    wayne0 Member

    357
    May 4, 2014
    Newburyport, Ma.
    2000 340 Sundancer
    Twin 7.4 ltr.V-drives
    ^^^^ Yeah, this!^^^^
     
  8. Ky Tundra

    Ky Tundra Member

    46
    Sep 5, 2017
    Kentucky
    1989 Sundancer 340
    Twin 454 Mercruisers with v-drives
    Thanks for the real advice. I'll post some pictures when I get a chance.
     
  9. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    Ky, I don't know the purpose of the inverter in your boat but if it were me I would not use it and get it out of there. You do NOT want to use an extension cord, or even have a 110v outlet in the ER.

    Several weeks after I bought my 340 the Norcold fridge took a dump. The dual voltage replacement was about $1200 and as I had just committed $3000 for the new swim platform and installation, I opted for a 110v AC GE fridge that fit the hole. It worked OK as long as I was on shore power or had the genny running. The problem was if I took a long cruise over 3 hours.

    I solved this by installing a Xantrex Pro Series XM1800. www.xantrex.com/power-products/power-inverters/pro-series-inverters.aspx and 2, 6 volt golf cart batteries wired in series to make 12 volts. The XM1800 is a slick inverter, designed for marine use, has a removable control panel that can be mounted remotely, a built in transfer switch and a 110 volt pass through circuit.

    Below the electrical panel on your boat is an access hatch. I made a marine plywood base painted with grey bilge coat and I glued that base inside of that access panel right to the inside of the hull using 3M 5200. I ran the 4/0 battery cablefrom the inverter, through a hole I drilled, and then sealed with marine caulk, through the bulkhead just in front of the generator. I ran the cables along side the generator. I found a battery box that stored the 2 golf carts end-to-end. I removed the battery that was on the port side of the engine room and mounted the new long battery box in its place. I think I removed the house battery.

    I wired the inverter to a spare breaker in the electrical panel then pulled the fridge 110 volt wires from the fridge breaker and into the inverter. In addition, I wired the 110 volt TV outlet near the v-berth TV through the inverter as well. This allowed me to watch TV and the DVD player when at anchor. Because of the inverter's built-in pass through and transfer switch when I was on shore power or the genny the 110v power ran from the breaker panel, through but bypassing the inverter, to the fridge. When I went off shore power the transfer switch kicked in and the fridge now got 110v power from the golf cart batteries through the inverter converted to 110v. It worked really slick and the batteries charged either from the engine alternator or the on-board battery charger. There was no inverter in the engine room, no extension cords and all was safe and to code. I did the work myself and I think I was into the whole project for about $600. You can buy the inverter on eBay for about $350 and I bought the batteries at Costco. Everything else was an online purchase.

    As I said, not sure of the reason for the invertor in your boat but you are wise to be concerned. Let me know if you need additional info on this.

    Shawn
     
  10. Ky Tundra

    Ky Tundra Member

    46
    Sep 5, 2017
    Kentucky
    1989 Sundancer 340
    Twin 454 Mercruisers with v-drives
    That's awesome. Thanks for all of the details.
     
  11. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    A couple more things about the inverter.... the remote display shows the voltage remaining in you battery, it also drops the output circuit if the voltage drops too low or gets hot.
     
  12. Creekwood

    Creekwood Well-Known Member

    Apr 26, 2009
    Oakville and Georgian Bay, Ontario
    '97 330 Sundancer
    2X 454 w/ vDrives
    I have the same Xantrex inverter with a 6v golf cart bank. Its installed in the cockpit storage compartment that is right above the batteries in the bilge. I used 1/0 battery cable for the feed to it because the run was short enough. Right now I have not yet wired the 110v side to the panel so I use a shore power cable to feed into the shore power input. The cable is pretty much out of the way so its a bit ghetto, but not dangerous. The inverter is pretty good for light loads. The little microwave works with it, but it labors a bit and its probably not good for it. I hardly ever use it for that. Truth be told I don't use it much. Our stays at anchor are not as often any more and we tend to not need the full 110v systems. I also have a 400w portable inverter that I can plug into the 12v outlet in the cabin to run the TV/DVD if needed and we use laptops and iPADs for electronic entertainment most of the time.
     
    NorCal Boater likes this.
  13. HUMPH

    HUMPH Well-Known Member

    Nov 4, 2009
    SF BAY AREA
    2003 410DA,
    2004 C14 Caribe
    CAT 3126TA's 350HP/
    50HP Honda
    Careful plugging inverters into the 12v outlets. If you utilize an inverter that is rated for to much wattage, the conductors feeding the 12v outlet become the weak link. Typically, these outlets have wire rates for 20 amps or so and 400 watts at 12 volts = 33 amps. This can break down the insulation on the conductors due to heating up too much. Try plugging the inverter in, load it up as you normally would, then feel the wires that feed the 12v outlet. I imagine they are pretty hot.
     
  14. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    I agree that that little inverter would not run much. For just my fridge it was perfect. I only suggested it as I know that boat and the OP didn't say what he wanted to use it for only that it was there and was it in the wrong place.

    My 52' Motoryacht had a 3500 watt inverter with 6 golf cart batteries and I could run almost everything on the boat (I didn't have AC) for a long weekend.
     
  15. Loyd Dinneen

    Loyd Dinneen Member

    240
    Jul 29, 2017
    Las Vegas
    1977 Sea ray 240 SDA cruiser w/ twin 470 mercs.
    Twin 470 Mercruisers
    I installed a 2000/4000 watt inverter and I mounted it in the small closet in the cabin which is way off from the engines. I only wanted it for the fridge so the fridge plugs directly into it and the battery I have is a grp 29 dual with 210 amp hours. The fridge only uses .01 volts per hour ( measured by keeping time over a 2 hour period). I have a 50 watt solar charger thats portable and I will use it when there is no shore power. When I don't need to use the fridge I just turn off the inverter and the fridge .The battery is not hooked to the engine charging system because I have twin 470 mercs and they have the old coolant cooled charging system and can't tolerate charging that many batteries.
    One good thing about this inverter is it also has two 12 volt plug ins on the top and three various amp usb ports on the front with the two 110v outlets. I paid less than 100.00 for it and seems to working great. Also it didn't need large cable since I wasn't going to run the whole boat just one appliance and the inverter isn't hooked into the rest of the boat. I do have a on board battery charger that is hooked to all the batteries and I use that to charge the batteries when there is shore power. It is only a 5/5/3 amp charger so it doesn't overcharge but just maintains.
     

Share This Page

Show Sidebar