Adding Outlet for watermaker

Hi All,


First off, I'm super comfortable with DC wiring, but not so much with AC, I seem to get caught in the weeds every time I get involved in it. As such, I usually avoid do anything but the most basic work on my AC system myself. In other words, please forgive my ignorance.



So here is my question. My boat is 120/240 VAC. My panel has one side that is 240 ( Batt Charger, Air Conditioner, stove) and another that is 120 (outlets, fridge, microwave). I have a Rainman Portable Watermmaker, which I love. It is 230V-50Hz, it draws 1300 watts, steady, when running. I have been using it by plugging it into an outlet, which is on the 120 side of my panel. It works fine but I have to be careful of other loads or it will trip the breaker. We load shed when using it, especially if on the genset (8 KW).


I've been thinking of installing an additional outlet in my lazerette in a waterproof box specifically for the rainman. I have an unused breaker on both sides of my panel. Should I use the breaker on the 240 side? Should the outlet be GFI?



Also, any tips on the breaker install? Or pitfalls that I should watch out for?


I don't want to do anything stupid or dangerous, but this project seems like it should be within my skills, given a little help from my TF friends.



Thanks in advance.

I am amazed it is still running if it is a 230V appliance and you have been plugging it into a 120V outlet...


Am even more amazed how you can get the plug into an outlet as it should have a different plug on it.


That aside...yes to both the 230 side and yes to the GFI (outlet or breaker)...


But seriously...someone needs to look at what's going on as it doesn't make sense to me that it has worked this far.

psneeld said:

I am amazed it is still running if it is a 230V appliance and you have been plugging it into a 120V outlet...


Am even more amazed how you can get the plug into an outlet as it should have a different plug on it.


That aside...yes to both the 230 side and yes to the GFI (outlet or breaker)...


But seriously...someone needs to look at what's going on as it doesn't make sense to me that it has worked this far.

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See? this is the kind of thing that I'm talking about that gets me fouled up. One spot on the rainman website describes the pump unit as 230V/50Hz. Another spot says 230V/50Hz OR 115V 60hz. The pump I have uses a standard three prong plug, so it sounds like maybe it is the 115V? I bought it used, so i'm not 100% sure. I've never looked for a spec plate or anything on it.

Well if it works fine and has for quite a bit...I would just add a simple 110V outlet with a GFI in it.


I did when my new water heater and battery charger came with plugs instead of being hard wired.


So just use an unused 110V CB on the panel and if a totally separate circuit, 14 or 12 ga wire and a15A CB. If you want to get fancy you can use a waterproof outlet box but I thing they are overkill unless in a potential spray area.

I would contact Rainman and ask if the unit is OK with 50 or 60Hz (some air con units are plated this way, for example). If it is, I'd use the 240V side of your panel. I have a 240V/50Hz Rainman here in Australia that I'd like to bring with me to the States next year when we come over to start the Loop...so I'll be interested to hear where you land with this.

I’m guessing rainman sells the unit in either European spec or US spec and you have a US spec model which is 115v/60hz.

You should start at your panel on the 120v side. Take an un dedicated circuit breaker and run a black wire from there to were you plan to place your outlet. Next you will need to locate your neutral buss for your 120v panel. Now if you have an inverter you will have two neutral buses you will need to determine whether your circuit breaker is on the inverter side or non inverter side. Once you determine which neutral bus, run a white wire from the bus to your outlet. Finally, you need to locate your ground bus and run a green wire from it to your outlet. The gauge of wire you use is determined by the length of your wire and the amp rating of your circuit breaker. There are charts on line to help you determine which gauge wire you use. If you use Anchor brand wiring you won’t need to worry about heat ratings or non tinned issues. If you use another brand make sure your reheat rating is
adequate.

Doug: With all due respect your explanation above is confusing and it indicates you do not understand your AC system. Have a marine electrician explain it to you and install an appropriate breaker and outlet for your water maker.


David

At the very least find the model number, serial number and call the mfgr. If you are guessing and it sounds like you are then you could ruin the unit if it truly 115V and you connect to 230V.

We cannot see it so can only go by what you tell us which is maybe a disaster awaiting if you are wrong.

I have quit electrical advice on any forum unless darned simple for this very reason.

C lectric said:

At the very least find the model number, serial number and call the mfgr. If you are guessing and it sounds like you are then you could ruin the unit if it truly 115V and you connect to 230V.

We cannot see it so can only go by what you tell us which is maybe a disaster awaiting if you are wrong.

I have quit electrical advice on any forum unless darned simple for this very reason.

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Me too. The OP's statement of his problem was confusing and probably wrong. Any advice given and taken (other than seeing a marine electrician) is likely to cause trouble.


David

You guys are correct, I'm guessing as to which one my unit actually is. It's at home in my garage (6 hours away) and I'm on the boat. I'll check it out tomorrow.


What got me confused is that I looked on Rainman's website, they only make one AC powered pump (well, two I guess as one comes as a package for a honda generator) but it appears they make the pump in two versions. A 230V/50Hz and a 115V/60Hz. Their website is really vague on this though, so I'll take a look.


I have a very basic understanding of my AC system, and like I said I'm easily confused by it. I've tried to study it, and study AC power in general, and I never seem to make any headway. Therefore, I usually just leave it alone. It's the only "system" on my boat that I feel this way about. I do all my own work on everything else from the dinghy outboard to the engines to the DC side, but I HATE AC. I do know where my neutral bus is and I know where my ground bus is. I understand voltage drop and wire sizing as well, though I always thought it had way more relevance with DC than AC.


I read all of the posts on here regarding AC power and my head spins. It's like I have a learning disability.


Also, we travel to some pretty remote places and I take pride in being able to repair and maintain the boat myself. I try to do the right things to avoid trouble where possible but be able get us out of trouble when needed. If something goes on my AC system I'm screwed. I don't like that feeling at all.



I can't stand having other people work on my boat as they generally do worse work than I do, are hard to find, take forever to show up and charge an arm and a leg. But I know my weakness is AC power systems, so I may see if I can find someone to do this for me, simple as it is.

Doug, bite the bullet and pay for an online AC electrical class. AC is no harder to learn than DC. You just need some one to start you at the beginning and it will quickly make sense.

It is possible that the motor is dual voltage meaning it can be changed by the wiring in the motor case or terminal box to operate on either voltage. Some motors are dual voltage and dual hertz but without KNOWING there is a real possibility of damage.
BUT you must understand what it is. That's as far as I'll go.

I am curious how long it has been working on the 110V outlet.


If it has over a hundred hours on it....hard to believe that it's still running fine and on the wrong voltage.


Anyone have experience with AC motors run on half voltage for long periods????


Heck many AC compressors seem to burn up with just around a 20% reduction in voltage.

OK, I got home from the boat last night and checked on the water maker pump this morning. It has a sticker on it that reads 115V/60 Hz, so I assume it is their "US model?


I'd like to do this project myself, as it will help me to learn more about my AC system, which is a good thing.


I spoke with a good boating friend who is much more adept at AC power than I am, he is going to give me a hand. My plan is to install a new 20 amp CB on the 120 side of my panel and a GFI in the laz. I'm going to lay out all the wiring (I have to pull the fridge to gain access) put not hook it up until he comes over and gives his OK.


One thing that still confuses me though. I've been reading marinco's publication on Marine AC power, which I have attached here. My shorepower plug and cordset is what they describe as 50A 125/250, but on my AC panel it says 120/240. How does that work?


Thanks. Sorry for the dumb questions.

Here's my unit, I found it on their site with some digging: https://www.rainmandesal.com/products/115v-60hz-electric-pressure-supply-unit/


What threw me off is that they also make this one, which looks exactly the same, and that they mainly reference on their site. They are an Australian company: https://www.rainmandesal.com/products/230v-50hz-electric-pressure-supply-unit/

Dougcole said:

OK, I got home from the boat last night and checked on the water maker pump this morning. It has a sticker on it that reads 115V/60 Hz, so I assume it is their "US model?


I'd like to do this project myself, as it will help me to learn more about my AC system, which is a good thing.


I spoke with a good boating friend who is much more adept at AC power than I am, he is going to give me a hand. My plan is to install a new 20 amp CB on the 120 side of my panel and a GFI in the laz. I'm going to lay out all the wiring (I have to pull the fridge to gain access) put not hook it up until he comes over and gives his OK.


One thing that still confuses me though. I've been reading marinco's publication on Marine AC power, which I have attached here. My shorepower plug and cordset is what they describe as 50A 125/250, but on my AC panel it says 120/240. How does that work?


Thanks. Sorry for the dumb questions.

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110/115/120/125 V are all used interchangeably...I am sure there are reasons but generally transparent to the end users like us.