Refrigerator invertor mismatch?
Kevin
I have a Refrigerator that runs on 12 volt, 110 volt and LP Gas.
According to the manual, the 12 volt and 110 volt are two different elements but both require 125 watts.
I have a 1000 Watt inverter -12 volt to 110 volt – but in trying to run the 110 V on inverter it shuts off & on indicating a overload. How can that be if it’s only 125 Watt required ? The inverter works fine on other applications, e.g., 100 watt Bulbs.
I need help. What am I not seeing or knowing ?
John
John,
I doubt if you are overloading the inverter.
My first idea would be that your inverter is not capable of producing a pure sine wave output. Instead of being a sweeping curve like swells on the water, the wave form looks more like something you made on an “Etch a Sketch”. Or, the electronics in the refrigerator may be causing some form of feedback to cause the inverter to shut down.
Would it be possible to supply more info on the refrigerator and inverter?
Finally, I have not seen refrigerators that have separate 12v and 110v systems. Usually, the base refrigerator is 12/24v dc and has a rectifier that converts the 110v down to 24v dc. If this is the case on your unit, you would be converting 12v dc to 110v ac and then back to 12v dc.
Thanks,
Kevin
Marine electrical standards
Kevin,
I am wondering if an electrical code exists for marine applications.
I have been told that the National Electrical Code does not apply to boats. Is there a similar code in place by which to judge the safety of AC power and wiring in a marine installation?
Would love to hear back on this!
Thanks,
Jerry
Jerry,
The boat wiring electrical standard that most OEMs try to build to is controlled by the American Boat and Yacht Council.
The main electrical standard is E-11. There are also several other separate standards that deal specifically with components such as battery chargers and galvanic isolators.
Thank you for writing.
Kevin
Improper ground shorting our rectifier?
Kevin,
Firstly let me say thanks for taking my question. I just re-powered my 24 ft boat from twin outboards to a single 225 outboard (Johnson).
The boat now has two batteries and while I want to keep them both, I only want one for starting and I want to keep the other separate for electronics (it’s a dual type deep cycle/starting). I have a
Perko brand battery switch I want to change to a basic “on/off” switch instead of having both batteries hooked to it.
I also seem to be having an issue with my Tach in that I don’t think it’s grounded properly and I think this caused my rectifier/regulator to short out two of the four bridge diodes (the ones to ground). So after this long winded explanation my two questions are as follows.
- How do I rig the switch into a “on/off” switch
- Once I’m on one battery with all negative leads going to the same battery (I have a negative buss bar), will this solve my ground issue with my rectifier/regulator so I don’t blow another one?
I’ve tested my others wires leading to my tach and I have continuity, so I’m thinking the ground has to be it.
Thanks again for letting me bend your ear.
Mike
Mike,
A great solution for your single engine boat wiring system is to use the BEP Dual Pole Battery Switch. This switch will allow you to turn both batteries off at the same time.
Another smart item to add would be a BEP VSR. This could be connected between the two load posts on your new battery switch. With the switch on and the engine running, the VSR will parallel the two batteries and charge both of them. With the switch on, if the system voltage gets too low, the VSR will open the circuit and protect the voltage in your cranking battery for starting. With the switch off, the connection is broken.
Always connect all grounds together in a 12v boat wiring system. Several different ground references are possible if they are not connected and could definitely be the cause of your rectifier failure.
Kevin
Possible to salvage old switch panel?
Hi Kevin,
I recently purchased an older runabout on which none of the switches seem to be working.
While there seem to be a few switch panels available for sale on the web, none appear to be anything that would fit on my dash. I checked with my local dealer about fixing the existing part, but he is quoting more for the job than I paid for the entire boat!
Can you give me any advice as to how I might be able to do this job myself? I have had a little experience with electrical work, but the “rat’s nest” that I’m finding behind this panel is fairly intimidating.
Thank you in advance for any help that you may be able to provide.
Switchless in Seattle
Dear Switchless,
Unfortunately, what you are describing is an all-too common situation with older boat wiring.
The problem often started with an old-line boat manufacturer who used inexpensive, highly corrosive wire while paying no attention to standard boat wiring practices – like using consistent boat wire colors for specific functions. The good news 
is that these sort of builders are usually (thankfully) no longer in business – the bad news is that someone, i.e. you, are now left to clean up their mess!
Compounding the problem, this already bad situation can often have been made worse by a series of boat owners either trying to fix the builder’s original mistakes or making sloppy boat wiring modifications of their own. Either way, the end result is often a boat wiring system where, at best, wires colors do not match and that does not work correctly – and, at worse, something catches on fire.
Up until recently, your only option was to rewire each circuit individually until all of your desired components worked. To do this properly, you would use the appropriate wire color for each individual component.
A more convenient solution might be a slick new system from EzAcDc that I saw for the first time just last week. What these guys have put together is a top-quality harness that can be used to completely rewire your existing switch panel.
The EzAcDc system appears to have all of the wires and circuit protection that you would need for your project. Once you are finished, you can connect the rewired panel to your current boat accessory harness or, if that is in as bad a shape as your panel, EzAcDc even offers complete boat wiring accessory harnesses that are terminated to be plug compatible to the repaired panel.
I hope that this is helpful.
Kevin
Proper circuit protection for depth finder
Hi Kevin,
I am adding a depth finder to my 2007 Crestliner boat and have an Accessory switch that is not being used.
Do I wire the red wire directly to the toggle switch or to the accessory circuit breaker? Also where is the black wire attached?
Thanks for your help!
Tim
Tim,
Before you connect the depth finder to the accessory breaker, check your depth finder owner’s manual for their recommendation on circuit protection.
Most boat builders have 10 amp breakers on their accessory switches. You may need to add an in-line fuse for this boat wiring project if the supplied Accessory breaker is not the correct size for your depth finder.
As for the wires, if you want the toggle switch to turn the depth finder on/off, then you can certainly wire it to the switched side of the toggle. Personally, I like to use the power switches that are provided on the electronics and not a separate switch.
The black wire should be attached to a ground buss at your helm. It is common for boat builders to not provide additional grounds for boat owner add-ons. Although it is not the best place to ground your depth finder, you can connect it to the chain of grounds from your existing gauges or your switch lights.
Thank you for writing.
Kevin
Connecting two batteries with different capacities
Hi Kevin,
Many thanks for making this service available – reading the previous posts has been a real eye-opener.
I have what I think is a silly question, however I’d like to check:
I have two batteries, both lead-acid sealed 12 volt. One is a 70 amp/hour, which wasn’t up to the job of providing enough current
to turn the engine over in the mornings after sleeping over on the yacht. So, I went out and bought a 110 amp/hour which is.
I’d like to use both of these batteries – with the large capacity to run the boat systems and the smaller as a reserve / starter battery. The wiring to a main switch that allows Battery1/Battery2/neither /both is in place.
I think that I can simply connect the two batteries despite their different capacities, so that when ‘both’ is selected they will discharge together and/or charge together.
I believe that if one has a higher voltage than the other at the point of selecting ‘both’ then the higher will discharge to the lower until they are equal. I don’t believe that the fact they both have different maximum capacities will affect their use.
Am I right? Is there any drawback to connecting two batteries of different capacities?
Thanks!
Evan
Evan,
You are correct. You can certainly connect two batteries with different reserve capacities in parallel with your battery switch. 
You may want to consider modifying your boat wiring system by adding an emergency paralleling VSR like the one from BEP Marine instead of the battery switch.
This switch will automatically parallel the batteries when the engine alternator is charging the system. When the system is not charging and the voltage is below 12.6 volts, the circuit will open up. This device also offers an emergency paralleling feature that can be manually operated or remotely from a button.
Thank you for writing.
Kevin
Reconnecting a complex marine electrical system
Kevin,
I just purchased a boat with a fairly complex electrical system, which was disconnected.
I am trying to piece it back together again with an incomplete
wiring diagram. Some components have been added, removed or changed since the original diagram. In addition not of the components provides documentation for this full scale system.
The system is comprised of
- One engine battery (actually 2 6v serial),
- One house battery (also 2 6v serial),
- Solar Panel with Solar Regulator, Alternator,
- Battery Isolator,
- Heart Inverter/Charger
- Dockside AC.
I would love to see a sample wiring diagram for this type of system if one exists anywhere. If not, my biggest question is where to ground the AC? I have read conflicting information regarding whether the AC & DC should be grounded to the same common ground.
Can you shed any light on the subject and/or direct me to resources that might be helpful?
Dazed & confused,
Andi
August 19, 2008
Andi,
I have never found a great resource for boat wiring diagrams. It usually comes be piecing together schematics from several sites.
One of my goals for Easy Ac/Dc is that perhaps someday this site will become a no charge repository/library for this type of boat wiring information, which would be a real aid to all of us who work with marine electrical.
So, if any of the readers know of a source for diagrams and schematics – or, if you would be willing to contribute a few of your own – please send me an email. If everyone contributes just a little, the amount of material available to all of us should be impressive.
On a more helpful note, please check out the Guest battery isolator manual. This should help you to correctly connect your battery isolator.
AC Ground
- All AC ground green wires are connected at your AC distribution panel.
- The AC ground and AC neutral are not connected.
- The AC ground should be connected to the DC ground.
The main reason for this arrangement is to trip an AC breaker if there is a fault between the AC and DC systems on your boat. Without this connection, when a fault occurs, all metal components connected to the DC system will become energized at 120v ac. There is too much resistance in the water and no direct path back to AC ground to cause the breaker to trip.
I hope that this is helpful.
Kevin
Wiring a switch to monitor two fuel tanks
Hi
I wonder if you can help me. I am trying to wire up a switch for a fuel gauge on my boat.
There are 6 terminals on the switch, three positions on the switch off port tank and starboard tank. There is one wire from each sender on the tanks, two wires from the gauge and it appears there are two live wires.
Could you please advise which terminals are for which wires?
Thank you for your help.
Gary
August 18, 2008
Gary,
You can easily wire your single fuel gauge to both fuel tanks using the switch you are describing.
- You will need to supply 12v power (usually purple) to your fuel gauge. This will connect to the B+ terminal on the gauge. You will also need to supply a ground (usually black) to your fuel gauge.
- Connect a wire from the sender (S) terminal on the back of your gauge to the center left terminal on your switch.
- Connect the wire from the port sender to the top left terminal on your switch and the wire from the starboard sender to the bottom left terminal on your switch.
The gauge will be powered by the 12v power of your ignition switch. The switch will select which tank the gauge will read.
If you would like to have the switch turn off the gauge, you will need to reroute the 12v power wire to your fuel gauge.
- Remove the wire from the B+ terminal on the gauge.
- Connect the 12v power wire to the right center terminal on the switch.
- Connect a jumper wire from the top right terminal to the bottom right terminal.
- Connect one final wire from the top right terminal to the B+ terminal on your gauge.
The switch will turn the gauge on and off and on depending on the position of the switch.
Hope this helps,
Kevin
LED installation is blowing fuses
Kevin,
I have a 1997 Stratos 18′6″ bass boat that I’m restoring. I decided to install multiple LED Lights throughout the boat, however I can’t get them to work right.
I connected all three together (neg & pos), then connected them to my fuse box, then to a toggle switch. When I put the fuse in, the lights come on, but when I flick the switch the fuse blows.
I was told to take the negative off of the toggle switch, but then it doesn’t work at all. Should I remove the negative from the fuse box too? But, then where do I ground it?
Any help would be appreciated.
Thanks.
Sylvester
August 14, 2008
Sylvester,
It sounds like something is wrong with your switch or your boat wiring.
The switch should have 3 terminals on the back. Your 12v power should be connected to the center terminal on the back of the switch.
Your LED lights should connect to the lower terminal if the toggle is on in the up position and to the upper if the toggle is on the down position.
Your ground for the switch light should be the last terminal.
You can also test your switch with an OHM meter.
- Remove all wires from the switch
- Put switch in off position
- Connect the OHM meter between center terminal and lower terminal
- OHM reading should be as high as the meter can read. This should be an open circuit
- Connect the OHM meter between the lower terminal and the upper terminal. OHM reading should be around 100 ohms
- Put switch in the on position
- Connect the OHM meter between center terminal and lower terminal. OHM reading should be 0 OHMS or as low as the meter can read
- Connect the OHM meter between center terminal and upper terminal. OHM reading should be around 100 ohms
Hope this helps,
Kevin
Will polarity affect compass light?
Kevin,
I am replacing a failed lighted boat compass with a duplicate.
The old one has 2 black wires attached to a disconnect type plug, but I don’t know which wire is positive and which is negative. The new compass has the wires labeled. I would like to wire the new compass using the old plugs.
Since I don’t know the polarity of the old wires, what will happen if I hook up the wires in reverse? Will it blow the light, the fuse or simply not work?
Thanks
Larry
Larry,
If the new compass light is a traditional incandescent bulb, then polarity is not a problem. If it should be an LED without reverse polarity protection, the LED will blow when it is hooked up backwards.
Typically, accessories that are lit with LED include reverse polarity protection. Hooking them up backwards means that they simply don’t work. When this occurs, just disconnect the wires, reverse them, and you should be ready for night time navigation.
In general, most compasses have incandescent lights, so you should be good to go!
For future reference, standard boat wiring designates black as ground and dark blue as instrument/compass light positive. Some boat wiring systems use yellow as their ground.
I hope that this is helpful.
Kevin
