generator question

Status
Not open for further replies.
I agree with Dennis and Larry. A 4500 watt water heater should only draw 18.75 amps at 240-volts and you probably would not allow it to run for "3 hours or more", so hook it up to the existing 20-amp breaker/receptacle and let her go.
 
grant - A couple of questions:
It's possibly your Powermate is wired differently that the identical appearing Troybuilt.

Does the gen have more than one CB? -- Maybe one for the 240V receptacle, and one for the 120V receptacles?

Does the 240V recptacle have a neutral? -- Or just a ground? I've only seen one where the 240V receptacle did not have a neutral.

I'm pretty sure you already know about this:
The gen connection likely will not be an SDS. You likely will have to go inside of the gen and remove the N-G bond. And you wil need a 4pole receptacle (separate N from G).

carl
 
A couple of other issues:
grant said:
i thought of calling the manufacturer, but being a large corporation, i'm sure they'd tell me, no no no. ...
Click to expand...
That's a good bet. There's nothing it for them to help you modify their product. But you should be able to get a wiring diagram and parts list. They might even be in the owners manual. I highly recommend getting those two before attempting any mods.

What you are contemplating is outside of the mfg scope. You are doing original research. I'm not against what you are suggesting, but it is a science fair project. So don't feel bad if things don't work out per plan and you end up shoveling the gen into the garbage can. (Of course that sort of thing has never happened to me :rolleyes: :mad: )

As has been mentioned, consider connecting the gen in its current configuration and see exactly what load it will handle. As for it making rated load - I suspect that residential grade gen mfgs lie about the ratings - hopefully not as bad as Sears compressor ratings. Every residential grade gen I've seen doesn't have enough engine - The RPM sags off under heavy load. I don't think any (resi grade) are designed to run continuous at even 80% .

If you do any load tests, I'd be interested in what you discover.

carl
 
Some survival gen thoughts (I'm pretty sure you have already considered all of this):

grant said:
... i just didn't want to have to go spend $600 on another one ...
Click to expand...
I understand that. Since I live in an area where temporary gen power a few times a year is called normal, I'll offer a few suggestions:

List out your survival priorities - here is a sample list:
Heat (top of my list - likely not yours)
Potable Water (If I didn't have a well, I'd have a tank)
Fuel for the gen and a vehicle
Preserve existing food (refrigerator/freezer)
Cooking (I use a two burner propane camp stove)
Lights (some of the newer camptype propane lamps with an attached small bottle are excellent)

The gen has to power up the "have to have loads". My "have to haves" are power for the furnace, well pump, refigerator. Everything else we can get around. Could be taking a washrag bath for a few days is an option.

grant said:
...if i could make this one run my water heater when the 'canes come.
Click to expand...
I don't know your expected power duration. If you are looking at a week, could be your water heater makes the "have to have". In that case, maybe you are looking at a little 1800rpm diesel. The idea of running a residential grade 3600rpm gas engine at 75%+, 24/7 doesn't sound real reliable. But if that is what you got, you might consider having oil and filters to change oil every other day (50 hours)

Just some thoughts - hope they help.

carl
 
thanks for all the replies.
you're right about the "have to haves". i really only need fridge & freezer - i already have full camping gear. and if the gen won't run the water heater, i'll heat water on the propane stove, like the old days.
this is all hypothetical, since the 'canes usually miss us here in jacksonville.
i just like to be prepared.
thanks again, guys.
 
IMHO it is quite a waste to run a generator in order to run an electric water heater. You end up wasting a good 70-80% of the energy value of the fuel. If hot water is so important, I'd figure out a way to use the waste heat off the generator (while powering your 'gotta have' loads) to heat up a tank of water at the same time.

That being said, if you run a 240V heating element at 120V, it will draw half the current (of course putting out only 1/4 the heat). It would take much longer for the tank to heat up, but unless the insulation is shot it would get hot eventually.

-Jon
 
Nice little thing about waters heaters is that you can connect one leg to the neutral bar and it will operate at half the wattage (ok guys was that the right word, resistance stays the same, voltage decreases) and get warmer water, but it might take longer.
Thanks Winnie, beat me to it.......
 
jrannis said:
Thanks Winnie, beat me to it.......
Click to expand...
Yeah, and by only three hours, too. :rolleyes:


(Just kiddin' :grin:)

But do remember that, when the voltage halves across a constant impedance, the current also halves, quartering the power. 1/2 x 1/2 = 1/4

Conversely, when voltage doubles, current also doubles, quadrupling the power. That's how convertible hot tubs can run on a 20a 120v. circuit. 6kw x 1/4 = 1.5kw
 
Status
Not open for further replies.
Top