Generators and generator transfer switches?

[best defense]

Hi everyone,

The recent power outages in the Portland metro area left my home without electricity for almost 4 days. Luckily I bought a small generator this past summer during the outages in relation to forest fires. My little $300 generator was good to run our fridge, a space heater, a lamp and even the tv/WiFi but I want to upgrade!

I own a 680 sq foot house that is all electric. No gas. I've got a normal fridge, a small reach in freezer, a 4 burner oven, hot water heater, washer, dryer, dishwasher, 3 cadet heaters, lights, tv, WiFi and some lights and plugs in the shed I call my shop.

All that said. What size Generator should I buy? Let me hear some opinions on the dual fuel generators, and how much Is a reasonable amount to pay to have a transfer switch installed in my house?

Also, maybe there's an electrician reading this who wants to take the gig. If so send me a private message.

I hope this thread promotes some good discussion on the topic and maybe next time more of us will be comfortable when the power goes out again.

Unfortuately, you listed the water heater and the stove. If you were to go to one of the outdoor or sporting goods dealers and buy a two or three burner gas stove you could get around that one fairly easily. A good one will usually cost $100 or maybe a little less. When you are not using it, it can be left stored in the garage for a long time and still be ready to go buy just hooking up a propane tank to it. The refrigerator and freezer are probably both 115 volt, so you would be OK there with most small generators, same for the other non heating appliances, but adding in the dryer to the 220 volt list is going to run things up to a minamum of 1000 watts, assuming that you don't run them all at the same time. If you plan to run a whole household on a generator, especially an all electric house, I would suggest that you check out one of the larger Generac generators that will run on either diesel or natural gas, and go ahead and get a building permit and have a professional install it.

 

[jbett98]

Most folks use their propane BBQ's to cook on when the power is out.

 

[solv3nt]

How is turning off your main, and backfeeding your panel any more dangerous than doing it with a transfer switch? Other than eliminating the possibility of human stupidity and actually not flipping off your main.

I'm a licensed electrical engineer, have MBA, small business etc, but everybody is capable of stupid things, myself included. Years ago, I was remodeling my kitchen and had the water off to let the glue dry in the kitchen. I took a leak, and went to wash my hands, damn, the water is off. I proceed to turn the water back on before checking that the valves are closed. Long story short, they weren't....

 

[Knopfplayer]

I went through this with a friend in Aumsville several months ago. He loses power frequently and his electrician already had a 'suicide' cord wired directly to a 220 breaker in the panel. He understands the operation and risk. During an outage he rolls the generator outside the garage door and connects the cable. Total time for deployment is about 2 minutes. He was more concerned about overloading the generator than about forgetting the circuit breaker sequence.

My part was to measure the various circuits, including each stove burner, with a loop ampmeter while he wrote down all the values. He can manage his load easily, and with relative safety, by keeping the total draw this limit. His water heater was right at the limit, but he could run it if he turned off everything else in the house.

He finished the house less than a year ago and I don't understand why he went all electric...

 

[Member 38805]

IBEW 125 JL ticket in my pocket.

Wow! I can only shake my head that a JL would recommend back feeding a panel, and possibly encouraging the average person to do things against NECA codes.
And more shocked to hear you've never heard of scenarios where JL's were harmed. Read it and weep.

back fed generator kills line man.

www.homesteadingtoday.com

Lineman Survives Shock from 7,200-Volt Power Line Monday [Archive] - Powerlineman.com Forums

Polk County, Fl Wednesday, September 2, 2009 10:12 AM EDT http://www.polkcountydemocrat.com/articles/2009/09/02/news/local/doc4a9dade2d4283632518688.txt A Bartow electric department employee escaped a brush with death Monday night when a downed line he was repairing became energized by a...

powerlineman.com

And OSHA is full of incidents:

Accident Search Results Page | Occupational Safety and Health Administration osha.gov

www.osha.gov

 

[Member 38805]

How is turning off your main, and backfeeding your panel any more dangerous than doing it with a transfer switch? Other than eliminating the possibility of human stupidity and actually not flipping off your main.

It's not foolproof, nor idiot proof. Where a transfer switch is exactly that! A transfer switch not only wont allow mistakes, but additionally is a 3 position switch, so it can be switched from normal power to no power, to generator power. But regardless of what the home owner might accidentally do, he can never accidentally make a wrong step.
Idiot proof is always much better.

 

[USMC1911]

So the first article is a Pike lineman. Anyone in the trade would understand. Second a COLD apprentice with LEATHER golves was handling a primary conductor. Backfeed in no way killed them but lack of and ignored saftey rules did.

 

[solv3nt]

Backfeed in no way killed them but lack of and ignored saftey rules did.

Technically speaking, electricity killed him.... Ignorance definitely played a role, but ignorance alone did not kill him. It would be like saying that gravity didn't kill a person that fell to their death, but the sudden stop at ground level did.

 

[USMC1911]

Looked through the first 10 of the OSHA incidents and not a single one is from backfeed of a customer owned gen that is used in the manner we are discussing. Like I said before, backfeed is something that is accounted for every day. Especially during large power restoration events. Lots of stuff in the trade can and will kill you. Backfeed is just one of the many. Like I said still never hear of a lineman killed by backfeed of a customer gen. Backfeed can come form almost anywhere.

 

[Kruel J]

And a transfer switch is still the right way to do it. Period. Just because I don't know anyone that's been killed in a car accident doesn't mean I'm gonna ditch my seatbelt.

 

[Dinglenutz]

And a transfer switch is still the right way to do it. Period. Just because I don't know anyone that's been killed in a car accident doesn't mean I'm gonna ditch my seatbelt.

I was an Oregon Journeyman in my misspent youth. What he said. If you're going to tie into the home electrical system, do it properly. The other reasonable option is to make critical appliances plug connectable and unplug them from the house, plug into the genny.

 

[Nick Burkhardt]

Do all of those home solar panel systems end up back feeding the lines when the utility power goes down?

 

[Kruel J]

Do all of those home solar panel systems end up back feeding the lines when the utility power goes down?

No. They have transfer switches.

 

[titsonritz]

No. They have transfer switches.

If they're done right.

 

[Kruel J]

If they're done right.

Goes without saying.

 

[titsonritz]

Goes without saying.

It should, but...

 

[solv3nt]

If they're done right.

Grid tied inverters have a UL listing that causes them to shut down on loss of power. There are some that utilize a shunt trip that causes the utility connection to be disconnected in loss of utility power. This trip is similar to an ATS as it will not allow for the battery/PV system from backfeeding.

 

[ZigZagZeke]

Going on 15 years ago we had a second breaker panel with an interlock installed. An outlet from the second panel is hard wired on the outside of the house. When we need the generator a pretty major cord (two male ends NO! lol just went and looked... it was late when I typed this) is plugged into the generator and that outlet. I switch off the breaker for the line power and switch on the breaker for the generator power. This is where the interlock comes in - only one of those breakers can be "on". The interlock physically prevent both from being "on" at the same time.

The second panel is a subset of all the outlets/hardwired equipment in the house - basically the kitchen, garage and family room. We cannot run the whole house off the generator. With a 5,500 watt generator we run:

Fridge
Small Chest Freezer
Gas Furnace
Gas Stove Top
Garage Door Opener
Approx 12 lights (many canned lighting)
Approx 10 outlets

We tend not to turn on the kitchen canned lighting, it's the majority of the lights and really works the generator. We run led lamps from the outlets, plus a couple of regular ceiling lights. Also the router, TV, receiver, BR, and my desktop.

A gallon of gas runs the generator between 2 and 3 hours. We tended to run it from around 6 to noon, shut it down for a couple of hours, then 2 to 8 or 9. But it never got really cold, other times we've run longer hours to keep the heater going.

Kept us comfortable for the week we were out of power.

One thing that's changed is the availability of really powerful, portable, rechargeable led lights. We no longer miss not having most of the house powered, we just use those in the other rooms.

Very similar to what we have. I put in as 60A sub-panel and moved all of our 120V receptacle and lighting circuits to that panel. All that remains on the main panel are things like the electric stove/ovens, heating system, welder, compressor, etc. There is a manual 100A Square D transfer switch mounted between the two panels. It's a break-before-make switch, with one side feeding generator power to the sub-panel and the other side feeding utility power to the sub-panel.

When the utility power goes down I flip the transfer switch, plug in the generator cord and start the generator. Actually, I prefer to turn off the individual breakers in the sub panel until the generator is up and running and connected. Then I can turn on one breaker at a time and load the generator gradually. We currently have a 9600W gas generator which will be replaced this year with a 15,000W dual fuel unit.

 

[solv3nt]

Very similar to what we have. I put in as 60A sub-panel and moved all of our 120V receptacle and lighting circuits to that panel. All that remains on the main panel are things like the electric stove/ovens, heating system, welder, compressor, etc. There is a manual 100A Square D transfer switch mounted between the two panels. It's a break-before-make switch, with one side feeding generator power to the sub-panel and the other side feeding utility power to the sub-panel.

When the utility power goes down I flip the transfer switch, plug in the generator cord and start the generator. Actually, I prefer to turn off the individual breakers in the sub panel until the generator is up and running and connected. Then I can turn on one breaker at a time and load the generator gradually. We currently have a 9600W gas generator which will be replaced this year with a 15,000W dual fuel unit.

One thing to consider, most breakers aren't switch rated, so try not to operate those things too often. Also, the UL listing for thermal magnetic breakers is a one and done deal for use, it is recommended that you replace them after an overcurrent incident.

 

[Dinglenutz]

Do all of those home solar panel systems end up back feeding the lines when the utility power goes down?

Most of them won't generate without a grid based 'load' to work with. If the grid goes down they won't even power your house. The 'offline' systems that will, have a transfer switch or the equivalent.