Generator Voltage Question

[jedens]

I just got a Coleman Powermate 5500 generator. One of the outlets is a 120/220V twist lock outlet. My question is how is this outlet set for either 120V or 240V? I don't see any type of switch or anything to switch between the two voltages. I'm concerned that if I plug a 120v appliance into it that it may be configured for 240v and burn it up. Thanks for any help
Joe

 

[gws]

Its 120/240 the same way the one on your dryer is.

240 across the outside legs.
120 between the inside and outside leg.

 

[jedens]

Does that mean that I just buy a 120v twist lock plug adapter with the 4 prongs on one side and a standard 3 prong 120v outlet on the other side and the adapter will be wired to the correct legs for plugging into the generator to get 120V?

 

[JATO_RaT]

Only one receptacle will fit into that outlet on your generator. If its a 120/240V 20 amp, that is exactly the plug end you will need to buy, no others will fit it. If its a 120/240V 30 amp, then you will need to buy that receptacle and only that one will fit the pinouts on the generator. The fact that your asking this question leads me to ask why are you using this outlet? Do you have a application for 120/240V device or are you building a receptacle box with a 240 Volt and a 120V receptacle? Perhaps you also have 120V outlets and a separate 240V outlet on this generator, at least many do set it up that way. To wire up the 120/240V you will need to know a little about what your doing, if you cross up one of the hots with a neutral, you will supply 240V to a 120V device. Rat

 

[hayden]

The plug in question should have 4 prings, one each for:

1) Ground
2) Neutral (not to be confused with ground)
3) Line 1
4) Line 2

Which prongs are wich will require looking at the plug for labling or checking the manual for the generator. I don't know off hand.

Between Line 1 and line 2 you will get 220V

Between Line 1 and neutral, and between line 2 and neutral you will get 110V.

Ground is just for safety and should never carry current in normal operation.

 

[jedens]

My reason for the question is that I have an RV sitting on my property and I intend to use the generator to charge the RV batteries. I've only tried it once so far and that time I just plugged the RV AC cord into one of the two standard 3 prong 120v AC outlets on the generator. I think those outlets have a 15 amp rating. Anyway, it was working fine until I turned on the air condition in the RV, then it tripped the breaker on the generator. I think the 120v/240v twist lock outlet on the generator has a higher amp rating, so I started looking at the generator manual for how to put it in 120v mode. Apparently there is no such switch and it depends upon the wiring of what is plugged into it. What I think I need to do is get a 4 prong twist lock to 120v 3 prong outlet adapter so that I can plug in my 3 prong RV plug into the adapter then plug the adapter into the 4 prong twist lock outlet on the generator. I think I'll also pull out my AC volt meter and check to see that I'll only be connecting between one hot line and neutral before I actually plug anything in. Thanks for the help!

 

[tomt5]

Jedens,

I have the same generator and EXACTLY the same question. I hope somebody here can answer this mystery. Why is this recepticle labled 120/240? I didnt find the owners manual to be of much help. We shouldnt have to build modified plugs to use this recp. What I finally decided was to use this only for 220 and just ignore the 120/240 label.

I think that Rat had the best explaination for this so far. Maybe thae 120/240 recp. is designed for wiring a box which can then be wired as 120 and 220v circuits.

Good question, hope we get furthur clarification.

tom

 

[chim]

The receptacle is marked "120/240V" because that's what it is. It will supply BOTH 120 and 240. For example, if you had a camper to plug in with a 240V service, the breaker box in the camper would accept two "hots", a neutral and a ground. From this box, a single pole breaker would supply a 120V lighting or receptacle circuit. A two-pole breaker would supply 240V to a large air conditioner.

This isn't exactly what you have, but picture two 12V car batteries connected in series. At one end there would be a "+" and the other would have a "-". the batteries would be connected to each other "+" to "-". With the two batteries connected in this manner, anything wired across both batteries would see 24V. You could still connect something across each battery individually and get 12V. This would be a "12/24V" equivalent.....kinda................chim

 

[Anonymous Poster]

ballancing the generator and 120/240

it appeares that you have two problems, one is that you want to run the battery charger and the second is that you want ot run other appliances. just as has been mentioned in other posts a generator has two sides to its windings. that way it can give two different 120 vac supplies. if you hook 120 to 120 you get 240. if you hook each of the 120 legs to neutral you get 120vac but you have two 120v circuits. so what you really need to do is to connect the battery charger to one side of the generator ( one of the 120 circuits) and connect the air conditioner to the other leg of the generator.

now the second part of the equation comes into play. you would like to have a somewhat equal load on each leg of the generator or you may find that you are popping breakers, this is called balancing the generator load, and may also be why you have had trouble. a generator does not like all the power to be pulled from one side of the windings and none from the other side. so you may need to plug something into the second set of 120v recepticles on the generator. there are usually two sets of 120 recepticles on the front of the generator one set runs off of one leg and the other set runs off the other leg of the generator. so there are two 15A circuit breakers on the front of the generator one for each leg. try plugging in a few lights to the oposite side of the generator, a couple of 100w lights would do, then try the charger and aircond. they may work now.
you also may be asking a lot from the 4000w generator that you have check the amperage draw on the airconditioner and the charger to see if you are exceeding the output of the generator.

alex

 

[pajoube]

Re: ballancing the generator and 120/240

alco 141,
Thanks for that great run down, was very easy to understand.
I am looking at a Honda 6500 generator (honda generator and honda motor) liquid cooled. Not knowing all that much about them I picked this unit with the intent that I could plug in almost anything and it would work. Ballancing the load really makes sense. As a back up for the home, going into a 12 circuit pre-wired transfer panel as well as field use for powering tools and welder.
PJ

 

[patrickg]

Re: ballancing the generator and 120/240

alco141, There may be more than just the two problems you mentioned, depending on the AirConditioner in question. If the unit isn't "soft start" or at least a "scroll" compressor the locked rotor or starting surge current may be something like 4-5 times the run current. 5000 watt gennys (likely an absolutely max short period rating) probably won't source 50-60 amps too well to start some RV A/C units and could "pop" a breaker trying.

In the "typical" RV installation, battery charging is provided by an auxiliary function of the "converter" which provides 12 VDC when you are plugged into "shore power" or are running the genny. These battery charging functions are pretty darned poor in most instances, a trickle charger at best. You might have a 12 VDC converter rated for 45, 65, or over 100 amps to run lights, radios, sat tv etc. but that is NOT how the battery is charged. It is a slow and innefficient method of battery charging to run a genny to power the converter to get the converter's charging circuit to charge the RV batteries.

You will get the job done much better and faster if you use a batery charger sized to charge the total amp hours of batteries to be charged at one time and power that charger from the generator. My converter AT BEST charges at 5 amps and as I have 325 amp hours at 12 volts that is way undersized. It is not too expensive to buy a good regulating (automatic adjusting) charger and be way ahead. You will save generator fuel and run time and you could save your or a neighbors nerves.

In my case, if battery charging were a perfectly efficient operation and my battery bank was at half charge, I would have to supply 162.5 amp hours to top it off. At a 5 amp rate that would be 32.5 hours. Battery charging is NOT 100% efficient so the actual time required is much longer. I use a 20 amp charger and wish I had bought a larger one. Your battery bank capacity and condition and built in charging rate will likely be different but this illustrated the main idea.

A parting shot: I sometimes camp where it is really dry (low relative humidity). For that situation I have a rooftop mounted swamp cooler (evaporative A/C) which uses about 5-6 amps at 12 volts depending on high or low speed. It is powered by the rooftop solar cells (up to 14 amps in bright sun) and boy are those solar cells quiet compared to the aux gen.

Patrick

 

[Spencer]

If your 120/240 volt outlet is a 20 amp outlet then this would probably work.

 

[Spencer]

If your 120/240 volt outlet is a 30 amp outlet then this would probably work.

These cords have a box on the end with both standard 120 volt outlets and a 240 volt outlet.

They are pricey but if you want to utilize all of the power available from your generator this is the way to do it.

 

[Spencer]

Here is the specs on these gen-cords.

 

[jedens]

Re: ballancing the generator and 120/240

Alco141,
Thanks for the explanation. The load balancing idea sounds like something I need to try.
thanks again
Joe

 

[bgott]

Grainger has just about anything but one thing about them, they sure are proud of their stuff! If a fellow was handy he could build the same cord for $50 or under. The last time I bought SO cable, which you could use instead of the SOW, it was under a buck a foot for 12/2 w/ground. 10/2 shouldn't be a lot higher. If I think about it I'll price the parts out at Lowe's or Home Depot when I'm there in the next day or two and post them.

 

[Anonymous Poster]

#10 sw cable

the cheapest 10-3 sow cable i could find was atr walmart in the rv section, colored orange and has a regular plug and recpticle on it about $27.00 for 25 feet, i cut off the ends and added my own special plugs ends to fit into my transfer panel and generator, used a separate ground wire on the generator (always a good idea). works well, and was the least expensive cord i could find.

 

[bgott]

I know this is an old thread but I finally got to Lowe's and priced out the cable. 10/3 SJEOW runs $1.24 a foot. I didn't get the price on the ends because I got distracted. If you find somewhere that stocks SO or SOW it would be cheaper. I also chased down the meanings of the letters...
S: Hard Service Flexible Cord
SJ: Junior Hard Service Flexible Cord
E: Thermoplastic elastomer insulation
T: Thermoplastic insulation
O: Jacket is oil resistant
OO: Jacket and conductors are oil resistant
W: Outdoor rated
The article I read listed "W-A" as outdoor rated but all I've seen and bought as outdoor cord had just a "W" on it.
After taking the time to find this stuff I just had to post it!

 

[pajoube]

bgott,
Thanks for posting this information; I have wondered what all the acronyms meant. I like you have many questions regarding the right purchase of a generator. I have identified what it will be used for but have not been able to find reliable information from the sales people.
PJ