Can I plug my 230V compressor (NEMA 6-20P) into a dryer (NEMA 10-30R) receptacle?
 

On 2004-10-20, Martin Mickston wrote:

I may have been *wrong* about that dryer being alone on one circuit.
There *is* an outdoor permanent air conditioner unit hooked to the same
fuse in the main circut breaker panel. When I shut down that main fuse
(which looks like four fuses wired together with a copper wire), both
the outdoor A/C compressor and the dryer shut off.

When you say fuse, I assume you mean circuit breaker. Since you say
it looks like four breakers wired together, could it be two double
pole breakers with a common trip? That would be one double pole for
the A/C and one double pole for the dryer circuit. What are the
markings on the ends of each of these four breakers? You could
definitely answer this question by removing the panel cover and taking
a look at the wiring, but that is not advisable if you are not
comfortable with it.

Cheers, Wayne

P.S. If it is two double poles breakers in the space of a single
normal double pull, why would all four be wired to trip together?
Perhaps because the inside pair and the outside pair need to trip
together, but it is not easy to do this separately?

When you say fuse, I assume you mean circuit breaker. Since you say
it looks like four breakers wired together, could it be two double
pole breakers with a common trip? That would be one double pole for
the A/C and one double pole for the dryer circuit. What are the
markings on the ends of each of these four breakers?

Boy, I've learned a LOT from you guys!
It's exciting to find out so much about things I just took for granted.
Thanks!

You are correct.
What I *thought* was four breakers wired together, *appears* to actually
be two sets of two breakers (one I can read is labelled "TYPE BRD,
2 pole unit J1076, BR3030").

It appears that one set of two breakers handles the dryer circuit.
The other set of two breakers appears to handle the outdoor A/C unit.
All four are wired together with a copper wire through the handles.

Why would they be wired together?

All I know is I seriously doubt the house is not to code as it was
just recently purchased and the inspector & lawyers gave the previous
owners about 5 pages of stuff to do. The electricians had to remove
all the wiring in the garage for example, (bummer, the previous owner
had lights all over, now the garage is dark) and they had to install
that copper wire (making it currently impossible to remove the main
circuit breaker panel covering plate without either cutting the
plate metal between the two middle breakers or snipping the copper
wire looped through all the four breakers).

Why would they have a common trip wire?

Does that play a role in hooking up a 230V x,y plus safety ground
compressor temporarily to the dryer x,y plus neutral-tied-to-ground
at-the-breaker circuit?

MM
P.S. Thanks for all the wonderful help. You guys are great!

Martin Mickston wrote:

When you say fuse, I assume you mean circuit breaker. Since you say
it looks like four breakers wired together, could it be two double
pole breakers with a common trip? That would be one double pole for
the A/C and one double pole for the dryer circuit. What are the
markings on the ends of each of these four breakers?


Boy, I've learned a LOT from you guys!
It's exciting to find out so much about things I just took for granted.
Thanks!

You are correct.
What I *thought* was four breakers wired together, *appears* to actually
be two sets of two breakers (one I can read is labelled "TYPE BRD,
2 pole unit J1076, BR3030").

It appears that one set of two breakers handles the dryer circuit.
The other set of two breakers appears to handle the outdoor A/C unit.
All four are wired together with a copper wire through the handles.

Why would they be wired together?

All I know is I seriously doubt the house is not to code as it was
just recently purchased and the inspector & lawyers gave the previous
owners about 5 pages of stuff to do. The electricians had to remove
all the wiring in the garage for example, (bummer, the previous owner
had lights all over, now the garage is dark) and they had to install
that copper wire (making it currently impossible to remove the main
circuit breaker panel covering plate without either cutting the
plate metal between the two middle breakers or snipping the copper
wire looped through all the four breakers).

Why would they have a common trip wire?

Because some idiot put it there. The house inspector is paid to find
stuff that's wrong but can be easily fixed (so as not to break the
deal). Some of the stuff they find is totally imaginary.


Does that play a role in hooking up a 230V x,y plus safety ground
compressor temporarily to the dryer x,y plus neutral-tied-to-ground
at-the-breaker circuit?

The 2 poles of the dryer circuit should be tied together. The 2 poles
of the air conditioner circuit should be tied together. The dryer and
AC should not be tied together (unless for some silly reason the
electrician used a 4-pole breaker and they were tied from the factory)

Some thin 2-pole breakers are installed in pairs, with 4 breakers in one
unit and the middle ones form a pair with internal common trip, and the
outside 2 form a pair with a metal clip that provides the common trip.
Maybe that's what you have (I'm too lazy right now to look up the number
you posted)

-Bob

(Martin Mickston) wrote in message . com...

What I *thought* was four breakers wired together, *appears* to actually
be two sets of two breakers (one I can read is labelled "TYPE BRD,
2 pole unit J1076, BR3030").

It appears that one set of two breakers handles the dryer circuit.
The other set of two breakers appears to handle the outdoor A/C unit.
All four are wired together with a copper wire through the handles.

Why would they be wired together?

Here's my best guess at what you got. Originally, there was a single
"2-pole" "common-trip" 30A breaker to run the dryer. This occupied 2
"slots" in the panel and carried the 2 hot legs to the dryer. Comes
time to add the A/C, there are no more slot pairs to add another
2-pole breaker. So the installer (probably the A/C guy) replaced the
2-pole with a pair of BR3030 "twin-pole" breakers. A twin-pole breaker
is like two half width breakers in the same package which can supply
two 120V branch circuits from a single hot bus in the panel. So, the
side-by-side pair of twins can supply two 240V circuits by considering
them as 4 poles with "inner" and "outer" pairs (poles 1-4 and 2-3) or
"over-under" (poles 1-3 and 2-4). The problem is, when one branch of a
240 circuit overloads and trips the breaker, it's supposed to trip the
other branch so that no part of the circuit is left live. That is why
common-trip breakers exist. The side-by-side twins were not originally
installed to do that, hence the home inspector flagged it. I've seen
worse combos.

Your situation is STILL potentially dangerous. A copper wire threaded
through the breaker handles is not the way to make a group of single
breakers into common-trip. Furthermore, one half of a twin-pole
breaker may not have sufficient strength to trip all 4 breakers hooked
together. The breaker manufacture sells appropriate hardware for
converting independent trip breakers to common-trip, and it is not a
piece of copper wire. If the hardware does not exist to fit that
particular combination, that combination is not meant to be hooked
together. Plus I don't think the BR3030 are listed for HACR service.
Your situation is almost certainly an "off label prescription" that is
not UL approved. Consider yourself so informed.

If you haven't had experience with working in a panel, you might not
want to start now. So the following merely tells some options. It's up
to you to make sure that it's up to code in your area and that it's
being done by qualified personnel.

Free up some slots in your panel by replacing some single breakers
with twin-poles for some 120V circuits. Depending on your needs for 15
or 20 amp branches, these would be Cutler-Hammer BR1515, BR1520,
BR2015 or BR2020 "replacement" breakers or BD1515, BD1520, BD2015 or
BD2020 CTL-tabbed breakers for notched bus stabs. This will leave you
enough space to install the PROPER separate 2-pole breakers for your
dryer and A/C, which would be breaker # BR230 in each case.

Another option is to replace the "homemade quad" with a real quad
breaker that's made specifically for this purpose. Cutler-Hammer makes
a model BRDC230230 which has inner and outer pairs hooked together to
make the equivalent of two 2-pole 230V breakers, but they also have a
less expensive BQC230230 for the notched bus panel if that's what you
have. No, you can't modify the cheaper one to fit the un-notched
busses.

See this for pictures:
http://www.eatonelectrical.com/unsec...B00300001E.PDF

%mod%

From:

(Michael Moroney)


writes:

In misc.industry.utilities.electric Michael Moroney
wrote:
| writes:
|
|There used to be 3-way Despard switches, but I never saw a 4-way one.
|Those are hard to find now days. Even the duplex switches that fit in
|a receptacle plate are hard to find in 3-way.
|
| The duplex 3 way switches aren't hard to find. I just bought two of 'em
| at Home Depot about 3 weeks ago. (they are both one ordinary, one 3 way
| switch, but they also sell duplex 3 way switches)

But are they of a major name brand?

Leviton, if I remember correctly.

| What's a Despard switch?

...

There is a strap with up to 3 rectangular holes and a couple tabs. This
becomes the yoke for a device assembly by inserting small separate devices
into each. They look like the duplex receptacle, except 3 holes instead
of 2, and smaller. Sides were rounded and the top and bottom were straight.

...

OK, I think I've seen these before, in an old house in Buffalo I lived
in.

I just had a need for 3 switches in a device, to switch the 3 components
of a bathroom light/fan/heater. I put in a Decora switch despite that
I dislike them. (what faceplate does a triple Despard switch take?)

A triple despard switchplate. Until Decora came out with a triple rocker switch
which fit into a single faceplate, a triple despard switch and faceplace.
factory labeled Heat / Vent / Light was included with every new HVL sold.


Speaking of multiple things in a device, I vaguely remember a kitchen
outlet in a summer cottage our family had. There were 5 outlets in the
single box device. (obviously no ground prong)
--
-Mike