I have a Delta 1.5 Hp dust collector I bought used, so I'm not sure
how old it is. I currently have it plugged into the 20 amp circuit in
my shop. I also have a Rigid TS3650 Table Saw, plugged into the same
circuit. This works fine if I walk over and turn on the DC then go
use the TS.
I bought one of those vac switches at Woodcraft the other day. This
is the thing you plug your DC into and then a tool. When you power on
the tool, the DC comes on. This works fine with my sander, mitre saw,
router, etc. But when I use the TS the breaker pops. This is new
electrical as of 1 year. I guess my question is does anybody know if
there is a kind of breaker that will handle a momentary spike like
this or could there be something wrong with my DC that is causing
this. I do know that if I try to run the DC on a 15 amp circuit all
by itself it will blow the breaker.
both are powering on at the exact same time, the high current draw is
can you put the saw on one breaker and the dust collector on a
table saws live better on a dedicated 20 amp circuit.
You can use a "slow trip" breaker - but be very aware of what you are
doing and the ramifications thereof.
This saw draws 13 A at 120 VAC.
Many (most) tools have a higher draw when starting than when running.
Also, make darn sure that your "20 amp circuit" is actually WIRED for
20 AMP and not 15. Just something to check.
Also, what else is using that line?
Immediately, or after it runs for a few seconds? What does the motor
dataplate list for amperage at 120v?
A DC is typically harder starting than a TC because of the rotary
inertia of the impeller. That will extend the DC's startup current
inrush for a longer time as compared to the TC. That's why
manufacturers of most DC's recommend a limit on number of starts per
Residential type circuit breakers are not usually instantaneous trip
and will tolerate a considerable overload for a short period - the
higher the overload, the shorter the period. So the breaker you have
should tolerate the startup "spike". But, If the DC is hard enough to
start and the running current is close enough to the breaker rating,
the starting inrush could last long enough to trip the breaker.
1.5 HP is getting pretty close to the limit for a 120v/15a circuit
even for a high efficiency motor. And a 120v/20a circuit is definitely
too small for a 1.5HP DC and a 13amp TS.
Yes, it is wired 20 Amp, 12 gauge yellow. I had the electrician wire
it for this when we renovated the house. Nothing else would be using
the line, I just power on one tool at a time.
How hard is it to change the breaker?
0. Remove breaker panel cover.
1. Turn off the target breaker.
2. Remove the wire by unscrewing the connector.
3. Lever out the old breaker (look at the new breaker for the technique)
4. Insert the new breaker - push it down really hard
5. Re-connect the previously disconnected wire. Tighten the screw really
6. Turn on the new breaker.
7. Replace panel cover.
Alternatively, you might try a radio controlled on-off switch. The kind that
allows you to turn on a lamp from across the room. Attach the remote control
to the table saw. Plug your jig saw (or a lamp) into the switch.
Start the saw, wait a sec, push the button to turn on the jig saw/lamp,
which, in turn, will activate the dust collector.
What you're trying to do here is avoid two high-current motors from starting
at the same time.
If you read the above posts carefully, I think you'll see that it isn't
a good idea to change the breaker without increasing the wire size,
since you are really pushing that 12 ga. wire. You didn't say how long
the run from the main disconnect to the wall receptacle is. The longer
the run, the bigger the voltage drop to the tools, particularly in
I suggest that, to make sleeping at night easier, you get that
electrician back, replace the 12 ga wire with 10 ga, and THEN go to to
30 amp breaker.
If you DO consider going that way, anothe option is to consider
having them bring 220 to that point. Your saw, and maybe your DC may
be able to be rewired to run on 220. If so, you won't have to replace
the wires (you mentioned that they are yellow, (which is
wrong,anyway)so, as long as there's a gound wire, you have enough leads
to do the job.
OK, I would agree with that on the surface. But bear with me a minute
and point out the folly of my logic. Say I put a 30 amp breaker in
there to handle the initial spike. The point of this entire
exercise is to have the DC running as little as possible and only as
needed. So, that being said, how dangerous is it if I have the 30 in
there, fire up the TS and DC for all of maybe 3 min at a time at the
absolute max, probably less, and that's it. I do this as a hobby, not
production, so my typical style is to turn on the TS, make 1 or 2
cuts, and turn it off. Is there something I'm missing?
Yeah. The 20 amp breaker is to protect the 12ga wire. A 30 amp breaker
will not do it.
As you said in your original post, you can manually start the DC then
start the saw without tripping a breaker. The short delay while you
move from one switch to another allows the dc to get up to speed and
reduce the current draw before you start the saw motor, keeping the
total draw under 20 amps. It is possible that a heavy cut on the saw
could then bring the total draw back over 20amps, but the wiring is
still protected by the breaker.
Your automatic switch is trying to start the DC while the saw motor is
still starting up, so the total draw exceeds 20 amps, and the breaker
trips. A 30 amp breaker might let you use the auto switch for startup,
but then if a heavy cut requires more current, you could exceed the
20A limit of your wiring for a more than momentary period.
Also, you have created a circuit that is , at ALL times, unprotected,
illegal, unsafe, and probably not covered by your insurance. A time
delay 20amp breaker would be a better option, but expensive.
Just flip the switches yourself...
You are a DIYer, after all.
Yes. 12ga wire isn't rated (by Code) for 30A.
It is a _VERY_ bad idea, akin to albeit not as bad as the penny in the
bottom of the fuse socket but the overcurrent condition required to trip
a 30A breaker on 20A-rated circuit is dangerous and should not be
Either find a sequential switch or use something like the remote switch
I posted a link to, rearrange to use two circuits and a control suitable
for that arrangement, pull 10 ga and upgrade to a 30A circuit or revert
to manually starting one and then the other from their respective manual
The problem is not the current needed to trip the 30 amp breaker. If the
current is there it will trip the breaker.
The problem is the 29 amps that don't trip the 30 amp breaker. That is
where the excess heat comes from to start the fire.
dpb actually suggested a 30A breaker with appropriate #10 wire, but a
30A circuit is also a bad idea. Other than that I agree with dpb's
A good solution is 2 circuits using a relay/contactor as suggested by
Bob Haller and dpb. The contactor coil connects to the Woodcraft
control. The contactor contacts are in the second circuit that powers
the DC. You could connect a time delay relay between the Woodcraft
control and the contactor so the DC would start a little later. A time
delay relay and contactor could also be connected to start the DC on the
same circuit after a short delay. It may be possible to add a time delay
relay to the Woodcraft control.
All circuit breakers that are used in a house have a time delay trip on
If motors are hardwired, a breaker may be larger than the wire size, but
it has to be designed properly.
Why not compromise and replace the breaker with the "slo-blo" variety? They
are built to accept temporary surges without going all crazy. One variety is
"High Magnetic Circuit Breaker" which will withstand temporary loads of up
to 20x its rated capacity. Here's one:
It may not be dangerous at all. The wire ampacity is based on the
temperature rise in the wire at a given current level and the maximum
temperature the insulation can withstand without damage. It could be
that for brief periods of usage and enough down time to allow the
wires to cool, you'd never exceed the temperature limits of the
wiring. But that's a pretty big if.
If you decide to go that way, and the danger isn't trivial, when the
fire department completes its investigation and finds a 30amp breaker
feeding 12 ga wire, expect the company that wrote your homeowners
insurance to refuse to pay the claim.
Incidentally, if the circuit is properly sized for the full load
amperage of the motors on the circuit, the starting inrush will not
trip a properly functioning breaker. You don't need to size the
breakers for the inrush, only the full load running amperage. If you
want to size for inrush, look at the motor dataplate and multiply the
amperage shown by about 5. Your 13 amp DC would need a breaker that
supported over 60 amps.
Well, you guys put the fear of God (and the insurance company) in me.
No 30 Amp breaker. I will look for the "slo-blo" though. What I
don't get is how this product ever works, at least with table saws. I
think I have a prettty standard setup for the market they are trying
I'll see how the breaker change goes...
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