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Really-Basic Transfer Switch Question...

  • Thread starter (PeteCresswell)
  • Start date
P

(PeteCresswell)

.... from somebody who knows *nothing*.

Looking at my breaker box.

Forget the double breakers for AC, kitchen range, and clothes
dryer. I'm guessing they're 220v.

That leaves sixteen single breakers, each rated "15" or "20"
(amps, I guess.... and 120v)

If I want to cover all but the single breakers, do I need a
transfer switch that can handle 16 "circuits"? Or can those
breakers be doubled up on the transfer switch so one "circuit"
feeds multiple breakers?

True?

Is installation as simple as hanging the switch next to the
breaker box and running the right wires back-and-forth to/from
the right places?
 
P

(PeteCresswell)

Per Solar Flare:
Transfer panels can be obtained with individual circuit transfers although
this is usually only seen in specialized generator packages. Most likely a
main switch transfer panel will be easily obtained with 16 or more
individual breakers. Buy the same kind and re-use your old breakers.

I think the concept *may* be starting to soak in.
------------------------------------------------------------------
- The outside feed to the existing breaker box gets connected to
a "transfer switch".

- The transfer switch has two inputs and one output.

- The output is, as above, routed to the breaker box.

- One of the inputs is the outside feed as above.

- The other input is a line to the generator.

- When one flips the transfer switch, it cuts off the
outside line and routes the generator's output to
the breaker box.

- One controls the max load on the generator partially by
flipping breakers in the breaker box. e.g. For a single
EU2000, AC=OFF, KitchenStove=OFF, ElectricDryer=OFF.

- All of the above seems to me to imply a single "circuit"
in the transfer switch
------------------------------------------------------------------

If the above is correct, what are multiple "circuits" on the
transfer switch used for?

Maybe to front end different things like AC, ElectricDryer,
KitchenStove, and "everything else"....thereby relieving the
operator of the need to flip breakers back-and-forth when
going between gennie and outside power?
 
B

Bruce in Bangkok

Per Solar Flare:

I think the concept *may* be starting to soak in.
------------------------------------------------------------------
- The outside feed to the existing breaker box gets connected to
a "transfer switch".

- The transfer switch has two inputs and one output.

- The output is, as above, routed to the breaker box.

- One of the inputs is the outside feed as above.

- The other input is a line to the generator.

- When one flips the transfer switch, it cuts off the
outside line and routes the generator's output to
the breaker box.

- One controls the max load on the generator partially by
flipping breakers in the breaker box. e.g. For a single
EU2000, AC=OFF, KitchenStove=OFF, ElectricDryer=OFF.

- All of the above seems to me to imply a single "circuit"
in the transfer switch
------------------------------------------------------------------

If the above is correct, what are multiple "circuits" on the
transfer switch used for?

Maybe to front end different things like AC, ElectricDryer,
KitchenStove, and "everything else"....thereby relieving the
operator of the need to flip breakers back-and-forth when
going between gennie and outside power?

Somehow you seem to be making this more complicated then it really is.

Most installations that have more then one power source are simple:

1. A Main entrance switch - possibly a requirement of your electrical
code.

Essentially is a main switch to connect or disconnect the entire
"house" from the commercial electrical system. Mainly in case of a
fire or other catastrophe. Also acts as a isolation switch if work is
done on the electrical wiring between the "Entrance" and the load
center.

2. A multi input switch, single output switch, rated at the maximum
total house current load. For example OFF - Commercial - Generator,
located after the Main Entrance (if required by local electrical
codes) or replacing the main entrance switch and before the main load
center. This switch MUST be the type that disconnects one circuit
before the next circuit connects..

That is it.

If the generator is not capable of powering the entire house then you
can restrict current requirements by (1) turning off certain
appliances, or (2) turning off certain breakers at the main load
center.

That is all there is to it.



Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
 
V

Vaughn Simon

Pete C. said:
If you're feeding it with such a small generator, the little "GenTran"
style transfer switch units are a better choice. Those transfer switches
are available at both Lowe's and Depot, and not just in a package with a
generator. Since they let you individually switch each circuit they
service between utility and generator feeds they make it a lot easier to
do load management on a small generator than trying to make sure you
turn off the correct breakers before switching a whole panel transfer
switch. Some models also have Amp / Watt meters so you can monitor the
load.

http://www.homedepot.com/webapp/wcs...Id=10053&productId=100030284&N=10000003+90401

That is how I do it! I have the 6-circuit Gen-Tran unit. One advantage or
that type of switch is that all of the wiring is done on the "user" side of your
branch circuit breakers. I think that makes the job safer and more in line with
skills of the amateur electrician. You are only dealing with #12 or 14 wire so
wiring is easy. The only down side is that you have a large number of
individual wires to connect inside your panel, (18 for the 6-circuit panel) but
the process is simple and repetitive.

Yes, I find it a bit limiting to only be able to power six circuits, but I
bought mine at a Home Depot "yellow tag" sale for a fraction of its value, so I
happily took what was available. Since it is conjectured, I can simply unplug
my Onan and plug a portable generator into the same panel if I have generator
trouble. This is a feature that has been very valuable to be in the past. As
already mentioned, the built-in wattmeter means I don't have to guess about load
management.

In short; even though I am a licensed electrician and can do it any way I want,
if I had the job to do over again I would still use that style switch.

Vaughn
 
P

(PeteCresswell)

Per Bruce in Bangkok:
Most installations that have more then one power source are simple:

1. A Main entrance switch - possibly a requirement of your electrical
code.

Essentially is a main switch to connect or disconnect the entire
"house" from the commercial electrical system. Mainly in case of a
fire or other catastrophe. Also acts as a isolation switch if work is
done on the electrical wiring between the "Entrance" and the load
center.

2. A multi input switch, single output switch, rated at the maximum
total house current load. For example OFF - Commercial - Generator,
located after the Main Entrance (if required by local electrical
codes) or replacing the main entrance switch and before the main load
center. This switch MUST be the type that disconnects one circuit
before the next circuit connects..

That is it.

If the generator is not capable of powering the entire house then you
can restrict current requirements by (1) turning off certain
appliances, or (2) turning off certain breakers at the main load
center.

That is all there is to it.

That's pretty much what I had in mind - albeit in fewer words.

But where do the multiple "circuits" come in with some transfer
switches? For instance http://tinyurl.com/5sum2h is touted as
having six "circuits".
 
B

Bruce in alaska

(PeteCresswell) said:
- When one flips the transfer switch, it cuts off the
outside line and routes the generator's output to
the breaker box.

- One controls the max load on the generator partially by
flipping breakers in the breaker box. e.g. For a single
EU2000, AC=OFF, KitchenStove=OFF, ElectricDryer=OFF.

- All of the above seems to me to imply a single "circuit"
in the transfer switch
------------------------------------------------------------------

If the above is correct, what are multiple "circuits" on the
transfer switch used for?

Maybe to front end different things like AC, ElectricDryer,
KitchenStove, and "everything else"....thereby relieving the
operator of the need to flip breakers back-and-forth when
going between gennie and outside power?

One BIG problem, with the above IS:
If your Genset Output is significantly Smaller, than the normal load
of your house, then you have NO Over-Current Protection for the Genset.
If you make a small mistake, in your loading of the Genset, like
having Momma forget, and turn on the oven or starting the Microwave,
while vacuuming the bedroom, your going to let the MAGIC SMOKE out of
the Stator Windings of your Genset, at minimum, and end up with a pile
of Copper Slag in the Genend Housing, or burning the house down at a
Maximum. You really need to have an appropriately sized Breaker between
the Genset and the Transfer Switch, to protect the Genset from
Over-Current. (appropriately being Genset Maximum Current Rating, plus
say 5%)
 
P

(PeteCresswell)

Per Pete C.:
If you're feeding it with such a small generator, the little "GenTran"
style transfer switch units are a better choice. Those transfer switches
are available at both Lowe's and Depot, and not just in a package with a
generator. Since they let you individually switch each circuit they
service between utility and generator feeds they make it a lot easier to
do load management on a small generator than trying to make sure you
turn off the correct breakers before switching a whole panel transfer
switch. Some models also have Amp / Watt meters so you can monitor the
load.

We've got a rather large breaker box - that seems less than 50%
used. viz: http://tinyurl.com/3pn2e5

Would there be any sense in trying to install the transfer switch
in the same box? Seems like plenty room.... plus it would make
a cleaner installation.
 
B

Bruce in alaska

Pete C. said:
What???? Every consumer generator has on board overcurrent protection,
and the EU2000i the OP referenced is no exception. If the OP switched in
too much load for the EU, he would just find himself in the dark again
and have to go reset the generator circuit breaker after correcting the
load situation.

Every UL Rated Consumer Generator built in the last 5 years, Maybe....
BUT the OP didn't specify the Genset he was using, and there are
literally thousands of Gensets out in the wild, that came from RV's
and other places that DON'T have built in Breakers. Like ALL the CCK,
NH, BE, type Onans, RM, CK, CKM Series Kohlers, and just about every
Lister or Lister type Powered Gensets. Not everyone in the world buys
New Equipment, that was designed for Uninformed Installations.
 
P

(PeteCresswell)

Per Bruce in alaska:
Every UL Rated Consumer Generator built in the last 5 years, Maybe....
BUT the OP didn't specify the Genset he was using, and there are
literally thousands of Gensets out in the wild, that came from RV's
and other places that DON'T have built in Breakers. Like ALL the CCK,
NH, BE, type Onans, RM, CK, CKM Series Kohlers, and just about every
Lister or Lister type Powered Gensets. Not everyone in the world buys
New Equipment, that was designed for Uninformed Installations.

Op owns an EU2000.

But your comment is relevant bc when I do install a transfer
switch it will be 30 amp/7500 watt no matter what.

For the extra hundred dollars, it seems worthwhile not tb locked
into any particular generator capacity.
 
P

(PeteCresswell)

Per Solar Flare:
but each
circuit has to be transfered.

Now we're getting somewhere.

What does "transferred" mean?

From context, I'm guessing one set of wires from the main box to
the transfer switch box and another set of wires from the
transfer switch box back to the main box - for each "circuit".
 
B

Bruce in Bangkok

To be frank, I can't imagine the system that you are describing and I
have been installing and maintaining generator sets at remote area
construction sites (jungle of Irian Jaya, Sumatra, Mountains of Java,
Viet Nam, etc., over the past forty years or more.

In those cases it was usually two generators which could be switched
on individually to provide camp power allowing the alternate unit to
be maintained or serviced. When you wanted to switch units the
electrician went out and started the second unit and manually flipped
one switch open and the second one closed.

From your description it sounds as though you have a generator that is
substantially smaller then necessary to power your house/installation
that you want to use in the event of commercial power failure and that
you want some sort of automatic device to shed load when the auxiliary
generator is switched on.

Of course, it is your house and your generator but I would like to
interject one comment. "The fewer automated devices you have to depend
on during an emergency, or in a remote area, the few chances there are
of something failing." Manually operated switches seldom fail,
automatic stuff does, quite frequently. As an example, see the Trace
Inverter thread in this group...

(I top posted to continue the thread logically.)

Those boxes are more special and usually only seen with a generator suplied
kit.

I am quite surprised at the low price. Maybe a nicer way to do it but each
circuit has to be transfered. Probably gives some nicer testing facilities
though. You could disturb only circuits that don't matter much to test your
generator occasionally.

The comment about whole house transferring was incorrect and probably not
desirable. Who needs the basement dehumidifier on secure power when you
generator/wind/solar/batteries may be limited?

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
 
V

Vaughn Simon

daestrom said:
This setup is a little bit cumbersome

I am not sure that I would use the word "cumbersome", just different. For
one thing, it gives you options that you don't get with a whole house switch
because it does not present with and "all or nothing" choice. Specifically, I
can run part of my house on the generator, while leaving the rest on the grid.
Why would I want to do this? First, for test runs. but also so that in heavy
weather with unreliable power I can run sensitive loads (electronics) as a
fuel-saving light load on the generator while the rest of the house uses the
grid for as long as it lasts. In nasty weather, this feature is more useful
than you would think.

Second, my panel is connecterized. (of course, you could connecterize most
any transfer switch installation). The connector allows me to disconnect my
Onan and substitute a portable generator, or even an inverter. Since my luck
with my old Onan has not always been stellar, this feature has been highly
appreciated in the past.

Vaughn
 
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