To avoid these ads, REGISTER NOW!

Generators - Switch Or No Switch?

BuickBoy

Well-known member
Joined
Feb 1, 2009
Messages
145
Hi all,

I live in city limits with underground lines, but the power fails occasionally. My parents have always had a generator in the garage. We had an outlet specific for the generator. It was wired the less ideal way, turn the main off and let it flow.

I'm interested in a simple 3500w portable for my own house now. I'm interested in powering my chest freezer (it has the venison in it!), my fridge, my stove, and more importantly my sump (I have foundation drains). Is 3500w sufficient?

I like the portable idea, because I can take it with me or loan it out if needed. I'm not so excited about the $300+ for a switch.

Thoughts?

Thanks!
 
To avoid these ads, REGISTER NOW!

Charles (in GA)

Well-known member
Joined
Jan 11, 2006
Messages
12,489
Location
50 mi south of Atlanta
Both the codes and the power company will require a properly installed switching device or lockout that will prevent accidental back feeding. Everyone says they would never do such a thing on purpose, they know better, etc, but when you are gone out of town and your wife has the neighbor help her get it up and running, the neighbor will not know your secret procedures. It needs to be foolproof and that is what the code and the poco expects.

Oh, and if that is an attached garage, be sure and don't run the generator in it. Lots of people die from stupid stuff like that.

Charles
 
OP
B

BuickBoy

Well-known member
Joined
Feb 1, 2009
Messages
145
It is attached. Generator would always be outside. Are there lockout devices for the main breaker? Cheaper alternative to a switch?

Sent from my Nexus 7 using Tapatalk
 
OP
B

BuickBoy

Well-known member
Joined
Feb 1, 2009
Messages
145
I see an interlock kit may be what I'm looking for. Opinions?

Sent from my Nexus 7 using Tapatalk
 

theoldwizard1

Well-known member
Joined
Feb 22, 2011
Messages
43,077
Location
SE MI
There are transfer switches that are "prioritized" so that only the items you want to receive power from the generator do. These are not automatic. They do cost close to $300 plus labor to install. Here is a typical one.

51406C.jpg


The problem with this solution is that you have to select your most "important" circuits when you install it. Only these can be powered.

A generator interlock is an alternative but it is similar to what you described at your parents house.


All of those appliances should have a plate near where the cord enter that states the amount of power (watts) each requires. Add them up and then add another 10-20% for cushion.
 

Charles (in GA)

Well-known member
Joined
Jan 11, 2006
Messages
12,489
Location
50 mi south of Atlanta
Yes, there are interlocks. They won't allow the generator back feed breaker in the panel (usually the upper right hand corner) to be closed if the main breaker is closed. You would first open the main, slide the interlock up and then close the generator backfeed breaker. You first want to turn off all high draw items before doing this. This allows you to pick and chose your loads. Heat up a tank of hot water, then open that breaker and close one for the stove for instance so you can use one eye on it.

Square D makes a couple to cover their line of QO panels. Of course you have to have a main breaker in the panel, and not a main lug panel.

Charles
 

nehog

Well-known member
Joined
Jan 2, 2010
Messages
7,935
Location
Jaffrey, NH
...

I'm interested in a simple 3500w portable for my own house now. I'm interested in powering my chest freezer (it has the venison in it!), my fridge, my stove, and more importantly my sump (I have foundation drains). Is 3500w sufficient?...

(assuming an electric stove... If gas, then the stove's electrical requirements are nominal.)

No, a 3500 watt generator won't power the stove. It might power the fridge and the pump, or the freezer and the pump, but likely will be straining hard to do all three.

You will need at least a 5KW generator (5 KW run, not surge) or better yet a 7.5 KW. And you'd have to restrict yourself to not using all the stove's burners on the 5KW unit.

BTW, that transfer switch shown in a post above won't work with an electric range: maximum circuit current for it is 20 amps and the stove will be a 40 amp circuit. Restricting yourself to a hot plate and/or a microwave (not used at the same time) will greatly ease your needs.
 

pattenp

Well-known member
Joined
Jun 4, 2008
Messages
10,175
Location
Virginia - USA
I have an interlock on my panel and a 30 amp power inlet using a 7500W generator. I've been satisfied with the setup. It gives me great flexibility with choosing circuits to power.

Edit: Have you seen this site for information about the interlock? http://www.interlockkit.com/intro2.htm

I see an interlock kit may be what I'm looking for. Opinions?

Sent from my Nexus 7 using Tapatalk
 
Last edited:

PowerGenGuy

Well-known member
Joined
Aug 25, 2011
Messages
299
Location
British Columbia, Canada
Spend the money and get the switch, and hire a pro to install it. Get a PERMIT. Then you are going to have a safe backup power system set up. Don't cheap out. The damage that occurs to your existing house and wiring, and cost, will be nothing compared to a good and safe switch installation. I have seen the damage caused when people have used a genset, fed power through the dryer receptacle, and then accidentally turned on the utility breaker. Do it right, and you will never have to worry.
 

jjpp

Well-known member
Joined
Mar 20, 2011
Messages
190
Location
michigan
Not sure how someone could run their generator with the main closed??????
It will over draw the genset and shut down the generator.
And yes I completely agree with the switch or interlock rules but just saying.....
 

Chilliwack Murray

Well-known member
Joined
Dec 10, 2012
Messages
1,501
Location
Chilliwack BC
Spend the money and get the switch, and hire a pro to install it. Get a PERMIT. Then you are going to have a safe backup power system set up. Don't cheap out. The damage that occurs to your existing house and wiring, and cost, will be nothing compared to a good and safe switch installation. I have seen the damage caused when people have used a genset, fed power through the dryer receptacle, and then accidentally turned on the utility breaker. Do it right, and you will never have to worry.

I'll second that. Below is a link for a product that the power company in Saskatchewan (Saskpower) recommends which is ideal for using a portable genset if not idiot proof, it is at least ***** resistant.

http://www.generlink.com/about_generlink.cfm

Personally, I use a 200A manual transfer switch which costs a fraction of what an automatic switch does however it does require installing a disconnect between the meter and the panel. When pricing a manual transfer switch, don't bother with a 2 pole 240V transfer switch, they are residential equipment, less common and therefore more expensive. Use an industrial switch 3 pole switch rated for 480V or 600V, they are higher quality and half the price. You can use two pole only or use the third to switch neutral if you have your generator neutral grounded... Make sure your electrician does this to code.

Anytime the genset capacity is less than the rated service you will risk overloading the genset and causing damage - usually to the electronics in your house from low frequency before the genset is damaged. Buy a digital meter that can measure frequency and check it from time to time.
 
Last edited:

2ManyProjects

Well-known member
Joined
Jul 18, 2013
Messages
757
Hi all,

I live in city limits with underground lines, but the power fails occasionally.

Which "city"? And due to what sort of causes, typically? Both of these questions will help answer a third, probably more critical, one: How long of an outage do you want to be "covered" for? Hold that thought.

My parents have always had a generator in the garage. We had an outlet specific for the generator. It was wired the less ideal way, turn the main off and let it flow.

As others have explained, that is a VERY bad idea -- as in, "so bad an idea that it can KILL people."

I'm interested in a simple 3500w portable for my own house now. I'm interested in powering my chest freezer (it has the venison in it!), my fridge, my stove, and more importantly my sump (I have foundation drains). Is 3500w sufficient?

If, and ONLY if, that "stove" is powered by natural gas or propane, 3-3.5kW might be marginally adequate. But if it is an electric range/oven, you absolutely will need a considerably larger genset.

Also, what about your furnace and/or other heat source? If the power fails in the winter, you do NOT want to be tempted to do things like run the oven to "take the chill off". Again, people have DIED from such silliness.

I like the portable idea, because I can take it with me or loan it out if needed.

I would ONLY consider a portable genset if I was absolutely certain that my needs would never exceed the 3kW or so which can be supplied by of of the "quiet" Honda or Yamaha inverter-based models. Neither you nor your neighbors want to listen to a typical open-frame "contractor grade" portable genset for hours (or days) on end. And even then, this approach has some major down-sides. This is where those questions above come in...

At least in my area, the event which has seemingly driven more genset sales lately than for perhaps the past decade or so put together was Hurricane/"Superstorm" Sandy. As you may be aware, the power was out in MANY places for a week or more; AND gasoline was next-to-impossible to get for a similar period of time, in part because the service stations could not run their pumps without electrical power. The upshot here is that if you want to make it through an extended power outage, you da*m well better be sure to have an "uninterruptible" supply of fuel. That in turn means either natural gas (which itself is not 100% reliable, as also proven during Sandy), OR storing enough fuel ON SITE to run the genset for the entire time, WITHOUT counting on outside replenishment. Gasoline (particularly modern ethanol-diluted gasoline) does not store well for more than a few months at a time. So, as a practical matter, we're down to propane -- and lots of it; you can effectively forget about schlepping 20-lb. barbecue cylinders back and forth to the exchange dealer, as you would be kept busy doing almost nothing else but swapping those cylinders around for the duration of the outage (even if the local supplier doesn't sell out within the first day or so, which they probably will). So to ensure a ready supply of USABLE fuel, a large-ish permanently installed propane tank is the only really practical answer.

All of which brings us to... Since the fuel source you will need cannot, as a practical matter, be portable, there is precious little point in having a "portable" generator (unless of course you need it for some other primary purpose, and backup power for the house in only a distant secondary consideration). Which in turn means a properly installed PERMANENT standby generator is THE way to go -- at which point, there's also no good reason to stop at 3-3/5kW. As a DEAD MINIMUM, you should be looking at something like:

http://www.generac.com/Residential/CorePowerSeries/7kW/
http://www.homedepot.com/p/Generac-...or-with-50-Amp-Transfer-Switch-5837/202214401
662a6551-083f-4595-a3a6-40c08bd21055_1000.jpg


And really, at this point, the whole "In for a Penny, in for a Pound" thing starts to apply -- meaning, going still-larger (up to and including a model capable of seamlessly powering the entire house) becomes more feasible (at least by comparison) than you might imagine.

I'm not so excited about the $300+ for a switch.

Time for an attitude adjustment: If you're worried about a $300 switch, you have not budgeted NEARLY enough to do a standby generator safely and correctly.

 

racerex

Well-known member
Joined
Dec 3, 2013
Messages
345
Location
NY
There are transfer switches that are "prioritized" so that only the items you want to receive power from the generator do. These are not automatic. They do cost close to $300 plus labor to install. Here is a typical one.

51406C.jpg


The problem with this solution is that you have to select your most "important" circuits when you install it. Only these can be powered.

A generator interlock is an alternative but it is similar to what you described at your parents house.


All of those appliances should have a plate near where the cord enter that states the amount of power (watts) each requires. Add them up and then add another 10-20% for cushion.

That's the exact transfer switch that I have. I have my heat/hot water, fridge, alarm/shop outlet, kitchen outlets, kitchen lights and second floor hallway/master bath lights on it. I have a 5,000w generator. I also have a small 2,500w generator that I use for carpentry projects that I can also fire up and run extension cords off of if I need power anything else. My friend is an electrician and he helped me install the switch.....the install went pretty quickly. I used the switch/generator for a few days during Sandy and all worked well.
 

theoldwizard1

Well-known member
Joined
Feb 22, 2011
Messages
43,077
Location
SE MI
That's the exact transfer switch that I have. I have my heat/hot water, fridge, alarm/shop outlet, kitchen outlets, kitchen lights and second floor hallway/master bath lights on it.

When you say "heat/hot water" I am assuming these are gas units that require a fan to operate, correct ?
 

cj7365

Well-known member
Joined
Feb 13, 2012
Messages
816
Location
New Mexico
Spend the money and get the switch, and hire a pro to install it. Get a PERMIT. Then you are going to have a safe backup power system set up. Don't cheap out. The damage that occurs to your existing house and wiring, and cost, will be nothing compared to a good and safe switch installation. I have seen the damage caused when people have used a genset, fed power through the dryer receptacle, and then accidentally turned on the utility breaker. Do it right, and you will never have to worry.

Well although I don't condone feeding through the dryer receptacle, whoever has their genset hooked up to the dryer recept and running and then goes and turns on the breaker deserves whatever damage they incurred.

How in the hell do you accidentally turn on the utility breaker, with a generator running, jeeze no wonder they put all those warning labels on everything
 

theoldwizard1

Well-known member
Joined
Feb 22, 2011
Messages
43,077
Location
SE MI
Well although I don't condone feeding through the dryer receptacle, whoever has their genset hooked up to the dryer recept and running and then goes and turns on the breaker deserves whatever damage they incurred.

Does the linesman working up on the pole deserve to be electrocuted ! Strong possibility.
 
To avoid these ads, REGISTER NOW!

nehog

Well-known member
Joined
Jan 2, 2010
Messages
7,935
Location
Jaffrey, NH
...
How in the hell do you accidentally turn on the utility breaker, with a generator running, jeeze no wonder they put all those warning labels on everything

That is a good question: but apparently it happens and has happened too often to ignore. People do stupid things, like: "I'm next to the box, so I'll flip the breaker on and turn off the generator because we have lights..."

Of course, the only reason he has lights is because the generator is on, and there's a lineman on the pole working on the lines, but that escapes him. Then all of a sudden that dead circuit becomes live and that lineman's family's future is bleak, at best.
 

racerex

Well-known member
Joined
Dec 3, 2013
Messages
345
Location
NY
When you say "heat/hot water" I am assuming these are gas units that require a fan to operate, correct ?

Yeah, the fan and controls for the natural gas fired forced hot air heat and the vent exhaust fan on the free standing natural gas hot water heater.
 

racerex

Well-known member
Joined
Dec 3, 2013
Messages
345
Location
NY
Well although I don't condone feeding through the dryer receptacle, whoever has their genset hooked up to the dryer recept and running and then goes and turns on the breaker deserves whatever damage they incurred.

How in the hell do you accidentally turn on the utility breaker, with a generator running, jeeze no wonder they put all those warning labels on everything

I know a guy that burned a nice mid-'30's house to the ground back-feeding through the dryer outlet. I don't know the full story as to what happened.

Side note, I met the guy a month prior to the fire. He was having financial problems and he was selling off a number of his cars. I went to his house to look at a pro-touring '69 Camaro and '07 Z06 Corvette. The Camaro was in a detached garage, but the Vette was in this wierd garage that was under a portion of the house. I was told that the Vette made it through the fire.....sounded like it just had some light water damage.
 

Jbullfrog

ALLIANCE MEMBER
Joined
Jan 9, 2007
Messages
2,347
Location
Avoca, Iowa
I have a Miller Trailblazer welder/generator. It is 11,000 watt. I spent under $2000 for it with 64hrs on it. Auctions are your friend. I have a pole-top disconnect with a generator connection at the base of the pole. It's just a matter of hauling the generator across the yard to plug in. It handles the house and has enough for the lights and furnace in the shop. We have a second transformer for the well, so we can turn the faucet on to know when the power is back.
 

Davefr

Well-known member
Joined
Jan 7, 2010
Messages
11,815
Location
OR
How in the hell do you accidentally turn on the utility breaker, with a generator running, jeeze no wonder they put all those warning labels on everything

The issue is that conditions are generally at their worst when it comes time to use a backup generator.

- There's no light
- Your cold
- You might be tired or stressed out
- You might not be thinking clearly

It's these factors that can cause mistakes to be made.

The is absolutely no margin for error backfeeding. I used to do it but quickly realized that I didn't want to rely on having to do everything perfectly when conditions are at their worst.
 

ambenz

Well-known member
Joined
Dec 12, 2010
Messages
4,236
Location
NW Chicago Suburbs
I do what your parents did...but have a Manual interlock safety guard on my circuit breaker box.
Pretty inexpensive to just make your own!
They want $150 for it here... http://www.interlockkit.com/interlockselect2.html
Made mine for about $25.

newCoverPic101613A.jpg


I have a 5550 continious watt generator I bought from a Toro repair guy in town for about $450.

g1.jpg

I now have it set up in the detached garage with a backfeed outlet.
It supplies power to 2 sumps, 2 refrigerators, 2 HDTV televisions, multiple lights, internet, a fan to exhaust garage and a microwave. I ran them all to verify it could handle the load...NO air conditioning though...for my 1,000 sq ft home,,,it works great but uses it 10 gallon tank in about 10 hours or less.
 
Last edited:

FarmerPete

Well-known member
Joined
Jul 24, 2013
Messages
258
Location
Lansing, MI
I'm currently at hour 108 of a power outage. In the 6.5 years I've lived in my house, I've never lost power for more than a minute before this. Now it seems it may be another day or two (or more) before I get power restored. I had never thought much of a generator, since I am cheap, and spending $500 on a device I hope to never need seemed silly. Having said that, I think I may be changing my mind pretty quick. I just wish there was an easy way to route a generator in to my garage sub panel safely and cheaply and still be able to provide power to devices on my main panel. If I have to install a transfer switch plugged in to my main panel, it would require +60 feet of heavily routed line to reach my back deck. It would also virtually pass inches from my garage sub panel. I suppose it's doable, but may be more work than it's worth.

If I wanted to install a NEMA L14-30 receptacle outside, I would obviously have to puncture a hole in my garage wall, as well as the siding, correct? Is there any consideration that needs to be made other than drilling a hole and using the appropriate caulk to seal the hole after you run the wires through it?
 
Last edited:

racerex

Well-known member
Joined
Dec 3, 2013
Messages
345
Location
NY
My panel is located in my shop area....which is about 25' away from my garage (attached/under my home). I ran 8-3 cable from the transfer switch (mounted next to the panel) to the L14-30 outdoor power inlet box. The ceiling in my shop is not closed up (it's insulated and I have tyvek stapled to the bottom of the joists...the tyvek provides a finished look, reflects light in my shop and it allows for easy access to run cable, etc.), so running the 8-3cable was easy. I did not install the power inlet box outdoors, I recessed it into an interior wall in my garage.....about 2' up off the floor and about 2' in from the roll-up garage door. The transfer switch came with a 10' long 30A generator power cord that plugs into the L14-30 outlet on my generator. I place the generator out in the driveway, I run the power cord from the generator into the garage and plug it into the power inlet box.....I then place a 2x4 on ground, next to the power cable and I manually lower the garage door....the door rests on the 2x4, not on the power cable. As a side note, I chain the generator to my kids in-ground basketball hoop.....as generator have been stolen in my area.
 

racerex

Well-known member
Joined
Dec 3, 2013
Messages
345
Location
NY
The switch that I have is rated up to 7,500W and they spec it for 10 gauge wire for up to 100' from the switch (i.e. distance from the transfer switch to the outdoor power inlet box). I ran 8 gauge in the event that I want to step up to a larger generator and transfer switch down the road at some point.
 

6768rogues

Banned
Joined
Nov 28, 2007
Messages
4,524
Location
Western NY
I put my generator outside and run two 12 gauge extension cords with quadplex outlets into the house. 5500 Watts runs the fridge, freezer, lights, sump pump, wood furnace blower, computer, and everything else so life seems normal. If you wire it to your electric panel, you MUST have an automatic switch, no exceptions. A mistake on a dark cold night might electrocute a utility worker.
I have several generators at my farm and one at home (best one I have). We seldom lose power, but I have had the generator for 20 years and it is nice to have. I get it out once per year and run if for a while under load, change the oil, fill it with fresh gas and stabilizer. It has electric start but I don't use it; batteries don't last when not used. It has never failed to start on the second pull of the cord.
 
Last edited:

geaugafletcher

Well-known member
Joined
Jan 9, 2008
Messages
215
3500 watts won't run what you described, an electric stove by itself would bring a lot of portable generators to their knees. I ran a fridge, furnace, washer OR dryer, a few lamps, phone chargers and a biggish CRT tv for a week on a 5500/8500max generator with no problem. Of course, it was best that all three electric motors not start simultaneously :shocking: ...an unlikely scenario, it never happened in fact.

Get someone with experience to show you how to set it up. In spite of what panic-y, self-righteous electricians tell you, a homebrew setup can be just fine if you have your wits about you. Only you can judge whether you trust yourself enough, act accordingly.

See this from John de Armond for some good reading:

http://yarchive.net/electr/generator_transfer_switches.html

ambenz also offers some good advice. Read a lot, be well informed, then do what you're comfortable with.
 

Jeff95TA

Well-known member
Joined
Aug 11, 2008
Messages
886
Location
Pittsburgh, PA
I inquired with my power company about the interlock and they wouldn't accept it since it wouldn't prevent a failure of the main breaker. The transfer switch is (I believe) a break-before-make setup.

I know the odds are slim of a main breaker failing in that manner, and I didn't want to find out what the ramifications could be, so I went with the transfer switch.

On a side note, what protects a linesman from the something like a solar or other power generating system where you're selling power back?
 

Stuart in MN

Well-known member
Joined
Sep 8, 2005
Messages
22,996
Location
Minneapolis
I inquired with my power company about the interlock and they wouldn't accept it since it wouldn't prevent a failure of the main breaker.

That's the thing about those interlocks - some electric utilities are okay with them but others aren't, so you have to check with your local utility to be sure before installing one.
 

jlmemt

New member
Joined
Jan 4, 2014
Messages
1
Location
Ohio
On a side note, what protects a linesman from the something like a solar or other power generating system where you're selling power back?

The answer is surprisingly simple, and I found annoying. It senses power like a automatic transfer switch and if there is no utility power it locks you out from providing any.
That is why I find a grid tie system, without battery backup, to be almost worthless in many cases. It is like everything else though, weigh cost vs. benefits. I decided I had no interest in grid tie, however I recently found one that does everything I want plus that so I may eventually go that route.
 

JoeFin

Well-known member
Joined
Sep 13, 2013
Messages
717
Location
NorCal - where the Rednecks Race
You tittled this thread wrong

Generators: Lawsuits and Manslaughter charges or No Lawsuits and Manslaughter charges

Because I'll tell you what - if I hear of a lineman getting fried in your neck of the woods I would give you up in a New York second.

Blatant disregard for human life and the lives of men required to keep Grandma's oxygen machine powered with electricity gets no sympathy in my book

Sorry but that's just the way it is
 

tfinniii

Well-known member
Joined
Aug 13, 2013
Messages
124
Location
Balto., Md.
Hopefully some of these switches are repairable ,as I had a friend with one that started to go bad(started loosing a circuit then another ),he moved wires around ,but he has to replace the whole switch to repair it.
 

Twiggss

Well-known member
Joined
Jul 3, 2011
Messages
425
Location
middle
You tittled this thread wrong

Generators: Lawsuits and Manslaughter charges or No Lawsuits and Manslaughter charges

Because I'll tell you what - if I hear of a lineman getting fried in your neck of the woods I would give you up in a New York second.

Blatant disregard for human life and the lives of men required to keep Grandma's oxygen machine powered with electricity gets no sympathy in my book

Sorry but that's just the way it is

Go get em tiger.
 
To avoid these ads, REGISTER NOW!
Top Bottom