Electrical Breaker and dust collector question

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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.
-Jim
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both are powering on at the exact same time, the high current draw is too much.
can you put the saw on one breaker and the dust collector on a different circuit.
table saws live better on a dedicated 20 amp circuit.
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I could do that, but then I couldn't use the vac switch.
-Jim
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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?
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Gus wrote:

13 amps for the saw and about the same for 1.5 HP dust collector. Typically a 110 volt auto-switch is rated for 15 amps or less. Also check the current rating of the switch before you burn it out.
--
Jack Novak
Buffalo, NY - USA
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So could there be something amiss with the DC as it blows a 15 amp breaker?
-Jim
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wrote:

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 hour.
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.
Tom Veatch Wichita, KS USA
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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?
Jim
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jtpryan wrote:

Almost trivial.
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 well. 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.
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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 Power-up mode. 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.
Pete Stanaitis ---------------------------------------------------------------
jtpryan wrote:

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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?
-Jim
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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.
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jtpryan wrote: ...

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 considered.
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 switches.
--
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dpb wrote:

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.
Dave
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David G. Nagel wrote:

I agree.
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 solutions.
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 overload.
If motors are hardwired, a breaker may be larger than the wire size, but it has to be designed properly.
--
bud--

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jtpryan wrote:

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: http://www.siscobreakers.com/browseproducts/HOM120HM.html
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wrote:

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.
Tom Veatch Wichita, KS USA
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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 to reach.
I'll see how the breaker change goes...
-Jim
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jtpryan wrote:

Jim;
You shouldn't fear the god of electricity or even insurance. Just have an extremely healthy respect for both.
Dave
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jtpryan wrote:

The product is designed for relatively low amperage devices, a sander and a shopvac for example. It's not meant to be used with two 1.5 HP motors.
--
Jack Novak
Buffalo, NY - USA
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