I've been getting a lot of contradictory information from my local
electrical contractors on my way to get an estimate for installing a
manual transfer switch between my generator and my breaker panel. I
need to clear the picture and hope someone can help me:
I have an off-the-rack Lowe's bought "Troy-Built" 5500W portable
gasoline generator and want to install a transfer switch so I can
by-pass the house's main breaker and run the generator to supply
temporary juice when undergoing extended loss or power.
So far I have gotten the following advice (and prices):
1. Install a 6-circuit manual transfer switch for $600
2. Install the same as above for $1,200 to $1,800, depending on what's
3. Told my generator cannot work with a transfer switch
4. Told I'd be better off using a Square D Interlock kit instead of the
6-circuit transfer switch so I can use the entire existing house
breaker panel and manage the load myself, not being restricted to 6
circuits (My breaker panel is a GE and supports Square D)
5. Told *never* to use GE Interlock (or any other brand) and stick with
manual transfer switches instead, whether 6- or more circuits
All the above info provided by 5 different state-certified, licensed
contractors that operate in my local area.
So, I have learned nothing except I need independent advice.
Not sure if this is right for you, but my electrician supplied me with an
outlet / two plug extension cord. The outlet is outside behind the garage
(to keep the noise down when generating). I was told to,when the power is
out, throw the main breaker to the off position. Then I plug in the
generator to the outlet fire it up and I will have power to my house. You
must be careful here not to use everything as if you have normal
electricity. Only use what you need. My power went off once since this hook
up was in place and I was able to see, have my fridge running and able to
watch satelite. My phone and security system was also powered. My genny is
7350 watt, so buy a genny that will work for your application.
This is not for everyone, YOU MUST TURN OFF YOUR MAIN BREAKER, YOU CAN KILL
A LINEMAN WORKING ON THE PROBLEM.
Do not attempt this without first consulting a qualified electrician. sorry
legal had to be done.
A qualified, licensed electrician will not install that, and it
will not pass code inspection in North America. No code anywhere
allows it anymore because it's part of the NEC now and all local
codes are built around the NEC.
Also consider your insurance company's response if this setup
is the source of any problems, plus the lawsuits possible.
You need a transfer switch.
Whats to install POP? its an outlet, the extension cord is an extension
cord. What code do I have to pass? Its just a supplied outlet leading from
the back of my garage. When the power goes I simply cut my main then fire up
the genny, result is the same but the cost is nil. I'm not an ijut therefore
I KNOW to turn off my power. My power doesn't go out regular enough nor do I
need a back up supply for medical reasons, I simply want it so I don't miss
HOUSE on Tuesday night! No need to go to all the expense of having transfer
switch for an occasional power outage. Its not like my genny is going to
come on all by itself anyway, someone has to go pull it out of the garage,
wheel it around back, cut the main and plug in the genny.
My electrician installed the outlet (at the time I didn't realize how
easy installing a breaker was) and to think that cost me 75 bucks! He also
TOLD me how to go about installing my genny the proper way. Hell I hated
having an extension cord running through my door.
So, I am viloating no codes nor am I hazzarding a linemans life in this way.
My house has two seperate panels (one for the shop and one for the house)
plus a knife switch box for the main supply.
Safety is the concern here first and foremost, the key to my genny is hangin
on the knife switch box, so there is no way I can run the genny without
first throwing that main..
THROW THE MAIN, notice how many times I brought that up, IT IMPORTANT!!!!
That is wonderful that you know "to turn the power off"..... But what
if you have someone over and they don't know, or you sell the house and
the new owners don't understand.
The Codes in North America are written to ensure the safety of everyone
involved. It is fine that it works, but when it is not done properly,
people can get seriously injured or even KILLED!
If for some reason the power supplied by your generator is introduced
to your homes main electrical wiring and then manages to travel to your
panel, through the main breaker and back feed your power utilities
system..... people can get KILLED!
YES, I UNDERSTAND THAT YOU KNOW! But you have many people around you
that don't... and we are all human which means that sometimes we
It is not worth taking the chance of taking a life. If it is done
right the first time, everyone is better off!
Sorry if this has come off as a Rant, but electricity is dangerous and
if mis-handled it can injure and kill. Any and all work should be done
under the strict guidance of a qualified tradesperson. And all work
should be inspected by your local inspection authority. Their job is
to make sure that everything and therefore everyone is SAFE!
AS TO THE ORIGINAL POST:
I believe that you have found the best option for your situation. Any
system that ensures that the main breaker is turned off prior to the
generator breaker being turned on (so that anyone can operate it
correctly) is the way to go. After that, it comes down to load
management as the size of the generator can only handle so many things
In addition, I think the process you have followed in making the
decision is what should be done in all occasions. Educate yourself and
if you find it difficult to assess the information that you receive,
contact independant individuals who have no vested interest in giving
you advice in one direction or another and have them explain the
information that you have received.
Best of Luck on your project.
Who is going to be at my house when the power goes out? If I'm not there
then sure as hell no one else is going to worrying about the power! If I
sell the house, the genny goes with me, the outlet can stay, that way if the
new owners decide to listen to a radio outback, well what do ya know theres
an outlet out ther, and guess wht, IT Works, its actually transmitting power
throught it. Hmmm, hoodathunkit!
My genny is a portable emergency power unit, it IS NOT hooked into the house
ready and on standby, it is in my garage. If the power goes out, I< I take
the genny out throw my main fire it up and I have power. Whats so hard to
Be aware that it is becoming common practice to pull meters on any home
that declines a check on the connection of a generator during storm
recovery and individual services are the last thing restored. So keep a
lot of fuel on hand as you may be in for a long outage. The cost of a
laboratory listed interlock kit is around sixty dollars. A weatherproof
generator inlet is around eighty dollars. So you saved maybe two
hundred dollars by using a suicide cord. The International Brotherhood
of Electrical Workers (IBEW) is committed to seeking manslaughter
indictments against anyone who causes the death of an outside wireman by
back feeding receptacle outlets. But of course you'll never make a
"This alternating current stuff is just a fad. It is much too dangerous
Its too bad that individuals like Shopdog just don't understand that
when it comes to electricity "rules are NOT" made to be broken.
These types just don't get the fact that we are all human and we can
make mistakes. Instead of spending a few more bucks to make 100%
certain that no one can get hurt, they find ways to cheat the system
and then when someone does get hurt, they say "Oops I didn't realize
that could happen!"
Wonder if this guy has a hot tub without GFCI protection, "cause GFCI's
are only a money grab for manufacturers" "Electricity doesn't kill
people, people kill people!"
This is exactly the problem. You are backfeeding the house panel
through your existing electrical system. If you or someone else
forgets to throw the main breaker off, someone will get killed. In
addition, in order to do this, your extension cord has an ILLEGAL end
on it that is live --- and it can kill someone too if not disconnected.
IF YOU DON'T BELIEVE US ELECTRICIANS, CHECK WITH YOUR LOCAL INSPECTOR!
Again Sorry about the Rant,
For anyone reading this ---- PLEASE, PLEASE, PLEASE ---- Just follow
the correct rules. It isn't worth someone else getting seriously hurt
or killed over such a simple thing as electrical safety. The rules are
set out for a reason --- usually because someone has died from the
result of improper procedure.
If you have any doubts about what you are doing seek the advice of a
qualified tradesperson or the local inspector to get the direction you
need to have the work done properly.
What Shopdog has done is unsafe and if inspected by a local inspector,
he would have serious issues to deal with! There is no need for it ---
especially with the newer relatively inexpensive solutions available.
Hopefully the IBEW, the local power supply company or the local
inspectors will find these people who take shortcuts before someone
You just brought up another reason why the interlock switch appears to
be my best option: the size of the generator.
Right now I have a 5500w but my daughter is building a home here and
has already indicated a desire to have her own generator as well. She's
having her house pre-wired for this purpose. So, I will eventually give
her my 5500w gen and purchase a higher wattage replacement.
Had i decided on a 6- or 8- circuit transfer switch, I probably would
not have been able to take advantage of the increased gen power of the
replacement unit unless I had switched out the 6- or 8-circuit for a
higher one (or just added a second 6- or 8-circuit switch) to allow for
higher energy loads. With the interlock switch, I can increase my gen
size to wnything I want and not worry about the panel, since the
intelrock allows me to use any combination of loads any gen I use will
Boy, you sure did get a lot of contracictory information. See a
couple of my inline comments below, too.
I am NOT suggesting this is a do it yourslef job unless you are
I purchased an Emergen Transfer Switch and installed it.
I bought a length of appropriate cable and the conntectors and
built a cable to connect the generator to the transfer switch.
The outdoor "disconnect" is the plug at the generator.
The cord comes in thru the wall and plugs into the Transfer
The transfer switch has ten switches (breakers): The are
wired as follows:
One 220 pair for 1 HP well pump (that's a ganged set of 2
One for the furnace,
None for AC; power problems here are always winter.
One for water heater, set of kitchen outlets, and ceiling
lights in two rooms.
One for lights in three other rooms
One for outlets in main living areas; living room,
One for computer room. Don't run your computer off a
generator unless you have a power conditioner.
The rest go to whatever was handy in the panel: lights,
outlets for coffeemaker, microwave, gas stove, things like that.
The big advantage of a transfer switch is that it allows you to
turn things on or off at will, thus minimizing what's energized
at any one time, plus it makes it impossible to feed power back
into the power lines outside. Each switch on it has three
positions: Power from generator, all OFF, power from outdoor
In our case, the only time we have any problems is if the well
pump and say the freezer or fridge turn on at the same time, or
the furnace fan joins in. The turn-on surges are high enough
that they pull the power down so far the generator really lugs
down hard to start them. That's very hard on electric motors and
puts excessive wear and tear on the generator. So far we've
never popped a breaker on the genset, but that's because we're
careful about which switches we turn on at the same time. The
Transfer Switch breakers are a set of ganged 25A for 220, plus 4
20A, and the rest 30A. It's oversized a tad at 7500W capability,
but that was my choice in order to be able to control various
In general, you want your genset loaded to about half of its
rating or less for extended periods of time. Beyond that you are
causing excessinve wear and tear on them. There ARE better
generators, but one pays a fortune for them.
It passed code inspection first time with not even any minor
recommendations other than I hadn't yet fully plugged the hole
where the cord comes trhu the wall into the house. But, I
checked with code enforcement BEFORE I did the job, and even
supplied them with a detailed schematic and load estimates. A
contractor would take care of all that.
My only regret is that I wish I'd gotten a deisel genset. We
usually get at least one 3 day outage per winter (most are less)
and keeping enough gasoline around and stored for that purpose is
kind of a hassle and requires storage planning to keep the fire
dept. happy. I checked into a large storage tank for the gas,
but that's incredibly expensive with all the codes and stuff it
has to pass: You can't just set it down and fill it, it turned
So, if/when this genset bites the bullet, I'll make sure the
next one is a diesel set - fuel storage is much less dangerous.
Any further questions, just ask; I'll help where I can. I'm not
an installer, not an electrical contractor, nor any "expert":
I'm an electrical engineer and know how to read and keep up with
what the codes require is all, plus I enjoy do it yourself jobs
as a rule.
One inspector, that was out for a wiring change I made for our
foster care bedroom, laughed at the neatness of my breaker box:
I'm sort of a neat freak.
But, I can glance into it, and tell you exactly which wire
in all that mess of 40 breakrs goes to which fitting; seldom
possible with most installations. Made wiring the transfer
switch a LOT easier!
Contractors logically can't spend the time to do that sort
of thing; nothing special otherwise <g>.
There are lots of links on the subject; these may help you
understand some of it:
-- REasonable product, will handle furnace, fridge, lights & a
1 HP well pump per my own experience.
-- Decent price, IMO IFF it includes everything from the plug
that goes into the generator to a fully functional Transfer
-- Unless you confused him, put this one in the round file.
What was the reason given? Totally incompetent unless there are
-- a. 5500W isn't enough to run your entire house. You'll have
to decide what you NEED to run and go from there. You'd have to
run around each time making sure everything was turned off that
was going to overload the gennie.
With an interlock, you have no way to "sequence" the load to
the generator: ALL electric motors, etc, would come on at the
same time and probably pop the breakers (or worse) of the
b. It would still have to be a transfer switch "type" in
order to meet safety and code requirements.
c. Your local code enforcement officer can give you the best
info in this are.
-- Never say never, but ... a standard interlock, I don't think,
will not meet the codes and/or isn't really the right way to do
it, unless it's specifically designed to function as a transfer
switch. Besides, see my comments in your #4 above.
-- Either there was a lot of confusion running around or you
have misheard things. I would also recommend against an
interlock, and DID opt for the transfer switch. It works well.
You might also consider one like mine - tri-fuel. It'll burn gasoline,
propane or natural gas. If you have one of the latter two, you don't have to
worry about storage problems - or a tank for diesel storage. Only have to
install a hookup from your current gas line - or hook it to a separate
propane tank if you like.
(substitute strickland in the obvious location to reply directly)
Please send all email as text - HTML is too hard to decipher as text.
Nat. gas is a very poor choice for backup power as it is often
interrupted along with the utility power. A backup generator needs to
have an on-site fuel supply to be reliable.
That said, if you have a big "hot dog" LP tank or an oil (aka diesel)
tank for your normal needs then that is the primary fuel to look at.
Gasoline is a poor choice due to the issues with storing any significant
amount or storing it for very long. It's ok for short duration since you
can siphon fuel for an extra vehicle for a few days. Don't siphon from
your only vehicle though.
Will work just fine, but limits you to having to select which six
circuits will have backup capability.
May or not be a reasonable cost depending on the installation issues. If
you have a fairly new panel surface mounted in a basement or garage with
easy access and plenty of space for the new switch it's probably pretty
overpriced. If however you have a hideously old panel flush mounted in
an old stucco's wall in a filthy, cramped, spider infested basement with
no room for the transfer panel then the price might be good. Point is
that parts are pretty well known, but time and labor could vary
Utterly false, any 120V or 120/240V 60HZ (US) generator can work with a
manual transfer switch. Some really small ones it would be pointless
with since they couldn't handle more than a refrigerator (if that) and
an extension cord would be just as easy.
A 5,500W generator is quite adequate to power a "normal" 1,500-2,000 sq.
ft. home just fine during a power failure. It can power a well pump, gas
or oil furnace (no electric heat though), refrigerator, small window A/C
(no central), lights, TV, etc.
The Square D interlock kit is a very good and inexpensive option that
gives you good flexibility and also an easy upgrade path if you get a
larger generator down the road. Since it interlocks the main breaker in
the panel with any standard two pole breaker in the 2/4 position of the
panel it can accommodate generator feeds up to the maximum branch
circuit breaker size of the panel which is 125A (30KW).
I just installed the Square D kit ($30) along with a new Square D QO
200A panel in my house. If you have a Square D panel it's a great
option. I would never install a Square D interlock kit on a non Square D
panel however as it would void all approvals and testing that the kit
has passed. If there is a similar GE kit made for your panel use it to
maintain the approvals.
The interlock kits *are* manual transfer switches, indeed they are
closer to the "real" large transfer switches that switch the feed before
the panel than the little six circuit panels are. The little six circuit
panels are basically six tiny little 20A transfer switches vs. one large
The interlock kits are quite new so that probably explains what you were
told in #5. Old electricians are leery of new stuff and prefer to stick
with what they are familiar with.
The little six circuit transfer switches are still a lot newer than the
"real" large single transfer switches, but they've been around long
enough for electricians to get comfortable with them. When they first
showed up on the market you would have heard similar comments to #5.
Number 3 is out in left field and is either a crotchety old fart who
doesn't want to deal with a small job, or someone who wants to sell you
one of the much more expensive packaged standby generator / automatic
transfer switch units like the Guardian units sold a Depot and Lowe's
(nothing wrong with those packages though, just more expensive).
Number 4 is entirely correct that the Square D interlock kit is a good
option, but should not be recommending installing a Square D kit on a GE
For reference here is the link to the Square D product announcement for
the interlock kits:
With a transfer panel you wont have the possibility of making a mistake
with the wrong circuits open. The 2 watt meters allow you to know the
load. A 6 circuit should cost 4-500 installed complete, the Generac kit
even has the exterior box, cable , sockets and plugs, it is pre wired
for HO instalation.
Knowing the exact load is far less important than you might think,
knowing what is on which circuit is far more important. If you
accidentally overload the generator you just pop a circuit breaker on it
or worst case stall it, annoying, but not a big deal.
The best thing you can do is map out every circuit in the panel and what
is on it normally. In my case I have a full CAD print of the house
layout with every outlet, appliance and fixture indicated along with the
circuit number it's on. Add in the data for the normal current draw on
that circuit and it will make load management very easy.
Generally you'll want to leave all of the lighting circuits on since
they typically represent very little load, particularly if you use a lot
of CF type lamps. The refrigerator and the circuit that covers your TV
would also typically be left on. Only large loads like well pumps,
furnaces and window A/C generally require load management.
Well, I already had a detailed map of all the breakers in my panel,
detailing exactly what you suggest, down to the specific location of
outlets, whether they have any appliance or fixture plugged into them,
etc. Of course, I also have each breaker identified according to the
grid. Since reading your post, I've added the individual loads to the
master grid map I keep on paper (and my PC).
The experience I've had managing loads with this generator, when I ran
several extension power cords into the house, is that I preferred to
use the following circuits:
1. Below ground well pump
2. Above ground (house) pump
4. TV outets
5. Computer outlets
6. One outlet in kitchen for 1 x 100W bulb on one small lamp (clip-on)
7. One outlet in master bedroom for 1 x 100W bulb on one nightstand
8. One outlet in another bedroom for 100W bulb on another nightstand
9. Two portable fans
The well pumps never presented a problem, for we scheduled all water
use for the same time period while avoiding use of other appliances at
same time. Of course, we avoided washing/drying clothes until after
power was restored.
I suffered for 12 days without power while using the above loads with
the current generator I have.
The main attraction of the interlock switch is that I can simply go
from room to room, or upstairs, etc., and simply turn off lights (or
appliances) in rooms not being used, then turning on needed lights (or
appliances) in the room breng occupied, etc. Being able to use the
overhead fans we have in each room is also attractive.
BTW, the lowest estimate I have received for a contractor to supply and
install a 6-circuit transfer switch was $600. One other contractor
quoted me 3 x that amount.
Does your unit have 240 out, then a 6 circuit 2 watt meter transfer
panel is safest, you can see whats being used and balance it easily. A
complete prewired Generac transfer kit at lowes might be 2-300$ and take
2-4 hrs install, mine was free at lowes with a 5500w Generac Generator,
if it doesnt have 240 out call the manufacturer to see what they
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