Revisiting the PTO-generator question

   / Revisiting the PTO-generator question #51  
John, good point. It's a 30 amp breaker. Our dryer outlet is the only 220v outlet we have in the house as the stove is gas. I got a chance to use the cord this afternoon. Almost made it through the whole day with only a few momentary outages, until 3:50 this afternoon when power went out. Since the window candles came back on, my wife thought line power had been restored and she began turning things on as if it was business as usual, even though the generator was running on the front porch.

Given all the ice we got, I was expecting a long night of no power and trying to sleep with the generator running. However, power was only out for a little over 30 minutes. I also learned, almost the hard way, that before you turn the main breaker back on you not only need to unplug the cord from the generator, but also the dryer outlet. /w3tcompact/icons/shocked.gif Nasty things could have happened if I had touched the open prongs.
 
   / Revisiting the PTO-generator question #52  
Unless you need portable power, I would stick with a
permanant mounted generator for the house. They run on
LP or natural gas so you don't have to worry about long
term fuel storage.

I bought a 8kw Generac for about $2000, it included a
tramsfer switch and the whole thing was pre-wired. If
you do the grunt work, an electrician could wire it in
a couple of hours.

It transfers automatically when the power fails and
will transfer back when the power is restored. It will
come on and run once a week to keep it excercised.

Took me a couple of days to install the whole thing
including trenching over to our main propane tank.

Using a generator without a transfer switch is VERY
dangerous. I know YOU will remember to turn off the main
breaker, but if you are not there, would someone else ?
 
   / Revisiting the PTO-generator question
  • Thread Starter
#53  
An amusing little aside. My generator showed up yesterday, and my wife, who has the flu and isn't feeling too well, went out to see the new "toy."

Her eyes were a bit blurry, but she read on the front, under one switch, the words "Brain Maker." She blinked a few times, and the words resolved into "Main Breaker." For a few minutes she was wondering what on earth I had bought this time!!

Actually, it would be neat if it had a brain maker feature.. maybe I could jump start my own brain.. ;-)

Best,
Bob
 
   / Revisiting the PTO-generator question #55  
Tev:

When you get one of those lined up send me a replica. Age and deteriation seem to have taken their toll.

Egon
 
   / Revisiting the PTO-generator question
  • Thread Starter
#56  
Franz, et. al.,

<font color=blue>I personally run 2 houses and my shops on a 7'5 kva machine, and have run both of them on a 3.5 kva. Load balance is more important than load capacity.
For the average guy, a half dozen 3 way switches will more than satisfy his need for a transfer setup, and save him a couple hundred bucks. If all you're worried about is the furnace and freezer, and sump pump, you can do it with a single 3 way and some extension cords.</font color=blue>

If I can trouble you good folks with one more dumb question...

I'm puzzled about the expense required to put in a safe transfer box, with lots of circuits, breakers, wiring, etc.

Why not just put in a single switch which allows power from either the electric service or your generator, but not both.. and then hook this to the main power-in line to your master circuit breaker box?

Then all you do is switch your transfer box over to generator mode, and turn on whatever circuit breakers in your main box you want to power? If you have enough generating capacity, you could leave them all on and power the whole house. If not, then just pick them selectively, based on what you want to run at any given time.

I figure my new PTO generator is rated for 17KW with 35KW surge, but I only have about 28 HP at the PTO. So figure I can put out about 13KW. This should probably (I'll find out by experimenting) power our whole house. If not, I just turn off some circuits at the main box.

When the power comes back on, I simply throw the single circuit transfer box back from the generator to the normal service position, and turn on any circuit breakers I may have turned off in the main box.

If this sounds ok in theory, then why not just an inexpensive, single switch, transfer box without all the fancy extra circuits? This would meet the safety issues, while providing a relatively low-cost solution, no?

Did that make any sense at all? /w3tcompact/icons/smile.gif

Thanks,
Bob
 
   / Revisiting the PTO-generator question #57  
<font color=blue> "I can put out about 13KW. This should probably (I'll find out by experimenting) power our whole house."</font color=blue>

Bob - Unless you've got electric heat or some other serious load, that should easily power an average house. Really, I would think the only time you'd have any strain on capacity would be if everthing tried to start up at once (surges from pump motors, refridgerator compressors, etc). This might be the case if the power was off for an extended period before you started the generator. If you make your switch to the generator properly, this should not happen. Just turn off your loads at the panel (or at the individual appliances) fire up the generator, then turn your loads back on 1 at a time.


<font color=blue>"Why not just put in a single switch which allows power from either the electric service or your generator, but not both.. and then hook this to the main power-in line to your master circuit breaker box?"</font color=blue>

Our panel box is alsmost exactly what you described, except it's built in to the circuit breaker box. Our main breaker is mechanically linked to a breaker leading to the generator plug on the outside of our house. You cannot turn on the generator breaker unless the main breaker has already been turned off. The breakers for the individual circuits can be flipped on or off as needed for generator operation.

The house was a new construction (just moved in Oct '02), and we had it set up this way from the start. Not sure how expensive this would be to retrofit to an existing system, but it can be done. Northern Tool (as well as any good electtrical supply house) sells the little transfer sub-panels which let you do the same thing on a smaller scale (cheaper to retrofit to an existing panel). For these you just pick key circuits you'd need in an emergency (power to furnace and blower, fridge, water pump, and few lights and outlets, for example). As I understand it, when you flip the main switch on these, it isolates those circuits from your main panel to prevent backfeeding into the electric grid.

John Mc
 
   / Revisiting the PTO-generator question
  • Thread Starter
#58  
Hi John,

<font color=blue>Northern Tool (as well as any good electtrical supply house) sells the little transfer sub-panels which let you do the same thing on a smaller scale (cheaper to retrofit to an existing panel).</font color=blue>

I guess this is where I get lost. Why is it cheaper to have a box with lots of little breakers and switches than it is to have a box with *one* switch/breaker?? And those "cheaper" boxes don't look very cheap, from what I've seen. I have an image of one little box ... power line from power company comes in one side, generator input comes in the other side, and out the bottom comes the connection to the main box. Throw the switch, and choose your input source. Zero chance of connecting both at once. I would think someone could cobble that together for $20-50, minus installation. See where I'm confused?

Thanks,
Bob
 
   / Revisiting the PTO-generator question #59  
If you trying to power up the whole house don't try this. I put a male plug on both ends on an extention cord and plugged it in. With a 20 amp breaker on the generator, same as the outlet plugged into there is no problem. It will power up one side of the 220 system in your main box. Works well to keep the freezer, regridgerator and some lights on. I wouldn't recommend any heating fixtures.
BE SURE TO TURN OFF THE MAIN BREAKERS IN THE PANEL FOR THE HOUSE! You will be trying to light up the whole neighborhood, and could cause damage to your generator when the power comes back on.
 
   / Revisiting the PTO-generator question
  • Thread Starter
#60  
<font color=blue>BE SURE TO TURN OFF THE MAIN BREAKERS IN THE PANEL FOR THE HOUSE! You will be trying to light up the whole neighborhood, and could cause damage to your generator when the power comes back on. </font color=blue>

I'm sorry.. I'm obviously not communicating what I mean very well.

With the idea I have in mind, there would be no *possible* way to have both the generator and the power service connected together. As for one side of the 220 line, I'm afraid I'm over my head here. Some people say I can run the whole house (in all likelihood) on 13KW, others say not. I dunno. /w3tcompact/icons/blush.gif I figured I would turn off all breakers, and then bring them on-line one at a time until I found it either could or couldn't handle it. But that isn't really the issue. The issue is, a SAFE transfer box that doesn't cost me a fortune. I thought I had a way figured out.

I think I had better just get Glen (our electrician) out and we can draw diagrams and he can tell me what will work and what won't. I'm afraid I don't know how to describe my idea any more clearly than I have, and obviously my explanation leaves a lot to desire! /w3tcompact/icons/smile.gif

Sorry to take up folk's time....

Bob
 
 
 
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