How do I hook up two motors on my boat?

Boat lift 220v

• QUESTION: I have installed a boat lift that requires 12A at each motor 220v. I have run 10/3 to the dock. It is attached to a 220v 30A GFCI breaker at the home. The breaker has a white neutral and is attached to the neutral bus. Questions as follows: 1) The motors do not require a neutral - does that affect the GFCI? 2) Do I hook the white that runs to the dock to the breaker if not being used - would guess no but does it affect GFCI? 3)Since I do not need the white, should I put in 3 hole outlets with 3 prong 220v plus (need to rewire the plugs & wire from the motors as I have reconfigured from 110 to 220) or should I run 4 hole and 4 prong with nothing hooked to the white on the plug? 4) I want to run a standard 110 plug also - what are my options? ANSWER: Why not just run a sub-panel off the main panel, that will get you your 220 volts [hot to hot] then you can use the neutral to make your 110 volt outlet? I did not understand what you meant by "wire from the motors" I am assuming you are speaking about simply changing the motors from 110 volts to 220. If that is correct, you are going up in voltage and down in current, so if the existing wire is suitable for the higher current it will be way suitable for the lower, as I have no way of knowing what your logistics are, maybe you need smaller wire for space, but you do not need a change of wire if it is of the proper size already for a higher current. Again if it makes it easier, you can leave the motors wired for 110 volts, if it fits your logistics, as there is no real cost savings by going 220 [there is some in power but very little, most is for new installs to allow for smaller conductor sizing. Also how are you starting the motors, a breaker is a terrible motor starter, and will wear one out in a lot shorter than normal time. A switch or control voltage relay is much better, or a motor starter. However you are not going to use these motors like an air conditioner, where they are on and off or even on for long periods of time, so with the normal usage of a lift, there is not the wear and tear as with a device where the motor is constantly cycling. If you look up the KVA use, you will find it probably does not make much difference as power usage, you can use smaller wire with higher voltage, that is generally the reason. The actual efficiency and usage of the motors is what determines the cost and KVA you will be billed for. As far as the GFCI instead of typing that all out, please go to http://ecmweb.com/mag/electric_gfcis_work/ It is a great site that explains it all. You seem to have an understanding of electrical circuits and the above site will explain all about GFCI circuits. But multiple motor connections are tricky, especially inrush current on the breaker, not the GFCI in this case, but the overall inrush the breaker will see dependent on when the motors start, in parallel or one at a time, motors will draw in general terms 6 times the rated current for a short time on start up, loaded or not, it makes no difference, that is the amount of current it takes to begin rotation, load or not. You of course need to wire the sub panel per NEC and local wiring codes, if you are unsure the relative small expense of a Certified electrician would be a prudent idea, for safety and longevity of equipment, considering you are using multiple motors, are needing GFCI protection, which is sometimes tricky with GFCI protection, [I said sometimes due to the motor insulation values changing due to moisture etc] Boat lifts are always a possible hazard if not installed correctly, for obvious reasons. But the only way you are going to get 110 is to have hot to neutral. So from your description I would thing it would be much easier to just install a panel on the dock, wired by code, and sized properly and safely. Hope that gives you a start, it is hard to picture exactly what you are having to deal with, so write back if I missed the idea. Will Babbitt ---------- FOLLOW-UP ---------- QUESTION: Will. Thanks. As a follow up and for some more info. I have a sub-panel on the exterior of my house - 60A - that runs some pool stuff. I have installed a 30A double pole GFCI breaker for the boat lift. The boat lift is approx. 125' from the panel. I have burried 10/3 wire (2 hots, neutral, grnd) and run to the dock in conduit. The lift has two 3/4hp motors. As it is an aluminum lift and I live in a very corrosive environment the mfg strongly suggests installing 2 outlets at the dock and simply plug and unplug the motors when using to combat electrolysis. Also suggested to run 220 to use less amps due to the length of the run. Also suggested to run 3 wire in case I decide to use a remote control in the future?? I think it runs off 110 but not sure how that gets me there. I could put another small sub-panel out there, but would rather not. But I will if there is no way to break off 110 for a normal outlet.

• Answer:

  Well if you have two hots a neutral and ground, you have 110 from one hot to neutral. So I am losing something here. Next it makes sense to run 220 for the smaller wire, using less amps is about all that helps as I explained, kva is kva is kva, volts x amps, 220 volts x 10 amps is 2200 110 volts x 20 amps is 2200, your savings is in the wire size needed to carry 10 amps that distance versus 20 but power is power and USING LESS AMPS is meaningless unless the savings in wire size and other components are extensive. Corrosive environment, what kind of corrosive, the water? Three wires for a remote on 110 is the hot to neutral, but a remote could be wired to a control transformer at any voltage, so I am with you so what? Next this combating electrolysis stuff by unplugging the motors, I understand most aluminum lifts install/provide zinc anodes on steel cables for that problem, but disconnecting is not going to hurt anything expect wearing out the plugs, a disconnect makes more sense. But I guess if you do not want a sub-panel out there, then no matter what you do, how are you going to split off the 110, I mean what was your original thought? A .75 HP motor nominal amperage full load at 230 volt is right around 7 amps, so you got plenty of wire size, I cannot find my wire book at the moment but I believe 10 is right at 30 amps three insulated max buried, ambient not considered for 125 feet. Why don't you do this, just draw me out what you want or wanted to do, nothing fancy and scan in it in to paint or draw in it paint and attach, or however you want, maybe I need to see in my mind what you envision. I am thinking you want to take the 220 to the motors and somehow get 110 from there. I mean you could run the 220 with the neutral to the motors, out into a box, and peel off one hot and neutral to a plug, but I would take it to a box, put the 110 plugs on the box, feed the 220 out to the motors, but not sure if that is going to pass muster, think you need a disconnect, I cannot advise you to do anything but what the NEC and local standards demand, period. Originally you were concerned with the GFCI, and if you read up on that site you know it is a comparative trip, so as long as nothing bleeds through it wont trip. Maybe instead of another sub-panel you could take it to a disconnect, and then wire an outlet to the disconnect, but you will have to check code. I had two places on the Lake of the Ozarks and Lord it is no wonder there is anyone alive down there. originally you wanted 220 wanted three wires, or four, which way, the new 220 appliance wiring is like this two hots to the new appliance, neutral to the appliance marked neutral, and then a NOW a another ground, where you may be confused is the motors need only two wires to run period. Everything else, the neutral only in the past was the ground, they since decided it is better to run both the neutral and the bare ground, for severe ground fault protection but the truth is both are ground bigger than hell, the neutral buss doesn't go to the ground wire at your home, the ground wire goes to the ground wire, but the neutral wire is ground, it is the only way to get 110 from 220 unless you transform down, and you don't want to mess with that. It is your dock and money and want tos, so not for me to be deciding, but it seems to me a sub panel for no more than you need is dirt cheap, easy, probably code, and a disconnect will keep you from wearing out very expensive plugs and receptacles. Unplugging stuff is as bad as using a breaker as a switch or worse motor starter. The disconnect will save you a lot of aggravation, here is some info on electrical properties of aluminum in this back and forth forum: http://www.thehulltruth.com/boating-forum/180832-zinc-use-prevent-aluminum-boat-lift-electrolysis.html You will get a lot out of their experiences, then send me what you had in mind in the form of a sketch and let me see if I can think of something, By the way you will find that electrolysis can occur when all current even ground is disconnected, that is why they use the zinc anodes, to take the unwanted current and sacrifice itself instead of the aluminum, some say it is too close to aluminum, but from what I remember zinc is what most boat lift guys use in salt water, whatever. By the way, if you are paying out the wazoo for the boat lift motors, and you might be, you might call a local motor shop and ask how much to EPOXY COAT, not encapsulate the windings, would cost. Well worth it, and have them paint the interior parts while they are it, it does not take long to disassemble a motor, the epoxy is pricey probably 30 bucks or better for the material, but they could pop them apart and pour the two part clear epoxy over the windings, it will take forever for anything to eat through that stuff, plus added paint on the inside end housings, if real expensive and the motors are cheap then just figure them as throw aways, but they are probably on a gearbox and all that is needed is to pull the winding shell off, and one endbell, not a huge labor job, but great for corrosion protection.