My house was built in the 1960's and is "electrically challenged."
Rewiring would be the optimal solution, except for the cost. ;-)
For now I'm trying to figure out if I can get a 220v dust collector
without rewiring. (The service box is maxed.)
My shop is right next to the laundry room. I already unplug the washer
and plug in a heavy duty extension cord to run my contractor saw -- I
found out the saw and shop vac on the same circuit can trip the breaker
halfway through ripping a 2"x4".
Any reason I couldn't build an extension cord to make use of the
220/110 of the dryer outlet, converting it to a standard 220 outlet for
a dust collector? Or is this A Very Bad Idea (TM)?
In Canada, separate ground wires were mandated sometime in the late '50s or
early '60s. Outlets for ranges and dryers were made law in 1970, at the same
time they required all NMD cable to have 90 degree celsius insulation, 60
degree insulation was dropped. US was much later in requiring these
This only an issue if the item hooked to the circuit has a 120V motor
along with other parts that are 240V.
All of the 220V circuits in my new house are just 3 wire except the dryer
circuit. This all passed electrical inspection.
If you can pull a new wire in why are we dancing around. Just put in a bigger
breaker, pull in some fat 4 wire and put a sub panel to serve the dryer and
We beat that subject to death a few days ago but we can hit the high points
again if this is a possibility.
;-) There's a large time & effort difference between making a short extension
cord & getting up in the attic where the the wild dust bunnies have free range.
The last time I was up there I almost came through the ceiling -- 40 year old
1/2" 3-ply plywood doesn't like my 250+ lbs... I wanted to try "fast" &
"cheap" first. ;-)
I just discovered this NG yesterday & I don't see the topic in my downloaded
messages. Do you recall the title? I can google group for the info.
That reminds me of visiting the shop that belonged to the brother of a
friend of mine. He had a rule: never plug white painted plugs into
red sockets or vice versa --- see they were all 110V connectors but
the red ones were wired 220V. He was very impressed that he a) saved
all that money avoid spendy 220 plugs and b) could use regular old
110V extension cords anywhere. Well you can guess where this is going
.... he plugs in two cords (one 110, one 220) and they are both orange
and indistinguishable on the other end........
Some years later the building burned down and nobody knew quite why.
Wilson -- Your writing shows you know something about electricity. Let
me as a question about dust collection system grounding. I've done
enough internet searching and reading in books & magazines to know this
is a bit of a religious issue. ;-) Suppose for arguements' sake I'm a
member of the Grounders sect.
- A neighbor told me the grounding is "weak" in the houses in our 40
year old subdivision.
- What good does it do to attach a grounding wire to the body of a
double-insulated but no ground wire router?
- Likewise, attaching to a TS that is grounded but not plugged in
doesn't do any good.
- If my DC isn't plugged in all the time it won't be grounded
Is there any reason to not separately ground the DC ductwork, such as
by driving a 6' copper rod in the garden outside the shop and running a
wire to it?
The reason is this won't clear a ground fault. (trip the breaker)
The ground has to be bonded to the center tap of the utility transformer. This
is accomplished in your service panel via the main bonding jumper. A separately
driven rod is required to be bonded to the service grounding system by the NEC.
What they are probably telling you is that some of your branch circuits don't
have grounding conductors in the wiring method. There has not been a
sifgnificant change in the code in reference to grounding the service in close
to a century.
Homes that were built to "GI Bill" or FHA standards after WWII should have a
grounding conductor brought to the box but you still could have 2 prong
receptacles. You can pigtail a ground out to a 3 prong receptacle if this is
true. If the house was built to minimum code it may only have a 2 wire cable
serving the branch circuits. The only fix in that case is to run supplimental
grounding from the panel or to rerun the cable feeding the circuit.
So what is your opinion of this solution, quoted from
Brent Dugan was the Maintenance Supervisor/Plant Engineer for a large
polypropylene manufacturer (oil sorbents) for 9 years. He shared his way to
eliminate those nasty static shocks:
"Our product was plastic and our conveying systems, both air and mechanical were
plastic. Polypropylene fibers traveling through 3" or 4" PVC piping creates
massive amounts of static electricity. Our problem was so severe that we had
sparks jumping 1 1/4" from our piping that would leave burn marks on your skin.
Our employees dreaded working with the equipment. We tried all of the available
methods you proposed and more; e.g., wire inside, wire outside, wrapped wire
outside, etc. We spent quite a bit of my company's money to try and solve the
problem with consultants and experts all to no avail.
I finally came up with a solution. It was so simple and inexpensive that you
not believe it. As you stated, static is electrons building on the surface of an
object. Well, I solved the problem by sticking 2" wide aluminum foil tape to the
outside and inside of the PVC piping and then grounding that tape. Putting the
tape on the outside of the piping was easy, just stick it on. Unfortunately that
was not enough and I also had to put a strip of tape on the inside of the duct.
Putting the tape on the inside was an interesting challenge. I wanted my tape
inside and tape outside to end up right next to each other with just the PVC in
between so I could use a screw and nut to ground the two layers together. I was
only able to make the aluminum tape with a backing like double-sided tape work
the inside. To do so I started by sticking the aluminum tape to the bottom edge
of the PVC pipe. Slightly peel the backing and adhere the aluminum tape to the
end of a piece of 1/2" emt, conduit pipe, or other long rod. Feed the aluminum
tape through the pipe as you unroll it from the roll. When you have the tape
through the PVC, stick the aluminum tape to the end of the PVC pipe. Now 'tape'
the backing to the rod then stretch the aluminum tape tightly angling it towards
the top of the PVC piping (12 o'clock position). This keeps it from sticking
prematurely. Now gently pull the rod out of the PVC which also removes the
'backing strip' off as you go. Keeping the aluminum tape stretched tightly lower
it to the bottom side of the PVC pipe. To smooth it onto the inside I slipped in
a longer piece of PVC and simply rolled that pipe inside to "iron" the aluminum
Having the tape back to back made grounding easy. I drilled a hole near each
end through both layers of foil, inserted a 1/4-20 screw from the inside of the
pipe, put on a nut to make a good circuit, then connected each section using 14
gauge wire. I connected each end with alligator clips to another strip of the
aluminum tape adhered to the concrete floor. That totally eliminated the massive
static electrical discharges and earned me a bonus!"
Apples and oranges. Grounding static electricity is a different animal than
bonding against electrical faults. As he says, you can ground out a static
charge in the manner he described.
>I connected each end with alligator clips to another strip of the
"> Wilson -- Your writing shows you know something about electricity. Let
Questionable report. Who knows what he means. Someone talked about two
wire wiring, which is pretty common. I wouldn't worry about it except in a
kitchen or bath, where upgrading could be worthwhile. There should be a
good ground rod at the box.
None. Did someone suggest it? Most such tools are plastic. Do you have
Are you talking about the duct ground for spark suppression? No, the TS
won't isn't a ground if not plugged in. Interestingly, it may have enough
leakage through a concrete floot to suppress static buildup, even if not
plugged in. This is spooky stuff and explosions are rare, but it's easy to
do the grounding and be sure.
True, but so what? If it isn't running it can't build up static???
No. Any sort of ground will do it. If you have a neutral connected to the
body (3 wire cord), just take the static collecting wire to the frame of the
I like someone's idea of the subpanel to serve the dryer and shop. You
could mount it at the dryer location and run wires to outlets in the shop.
Check the feed. It's probably 10 ga for a dryer. That's rated at 30 A, but
can do 40 in tool service, although that's not "legal". I think the 30 A
main we discussed, either in the main box or in the sub will do you fine. I
don't remember if your DC is 120 or 240, but if it will run on a house 120V
circuit you would have the 240 V circuit for big tools. Otherwise, you'll
have to do both on 240, which is probably OK.
I looked back and find your question ambiguous. Are you running the saw on
120 from the dryer outlet, or 240? I'm sure the vac is 120. If you don't
have the DC, just put the saw on 240 and you're there. Rigging the panel
and a couple of plugs will be nice for you and make you ready for a big
planer! Don't forget, you can also put in a 120V 30A circuit if you need it
for a tool that won't go on 240.
Good luck and let me know if you need help,
I am usually slow to jump on the "you need a sub panel" band wagon but from
what you have said here (out of circuits, questionable grounding etc) this may
be the best long term option. Then you would have the ability to install the
circuits you need in your shop and be assured that the grounding pins of your
tools are actually grounded.
If you are still going with the "extension cord" route, give me the name plate
rating of your dust collector (voltage, HP and FLA) and I will tell you how to
set it up.
The answer will probably start another fight ;-)
If your dust collector is 1HP or less at 240v you can probably use a 14ga cord
... on that 30a breaker and still be within the code. (using the NEC article
I currently have a Sears 110v shop vac which doesn't do too bad with my
sealed-up contractor saw and router table. But it would be overwhelmed by
what I hope to be able to afford in a little while, a joiner & planer.
Plus, I've been reading about the health hazards of micro-sized sawdust, and
according to the site below 800CFM is needed to suck up all the little
All the 800 CFM DS's need 220, which I don't have in the shop yet...
I still advise against trying to use the dryer circuit for any 120v loads but
if your dust cyclone is 240v you could just use a hard service cord, sized the
same as the manufacturer recomendation and put a dryer plug on it.
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