# How to get HF 20A Dust Collector working at 15A or less?



## JavaGeek (Jul 25, 2010)

How can I get a 20 amp dust collector with an induction motor to only use 15 amps? Also, how can I measure how much current I am using?

I ordered a heavy-duty speed control  from MCS Had 2 questions:

Is there any reason this shouldn't be used with an induction motor (I know nothing about induction motors...is it troublesome to throttle their current?)
How can I figure out how much current it is using?

I have a kill-a-watt which I use around the house to measure computer power consumption, but it's only rated for 15A. I don't want to set the DC too high and burn it out. The company doesn't appear to sell anything rated higher. Does anyone know of any tools or techniques to measure power consumption?


I am trying to configure a router with a dust collector in a porter cable omnijig. I am using a switch so that the DC turns on and off when I turn on/off my router.

I tried at first using my trusty shop vac, but the jig is just too large and is designed for an actual dust collector, so I bought the Harbor Freight 2HP Dust Collector after hearing wonderful reviews about it. 

Unfortunately, it uses up to 20amps and every switch but the $120+ wireless combo is only rated for 15. I ruined a crappy iSocket switch and bough the iVac switch and trigger the built-in breaker each time. (it's the first time I've ever complained about a harbor freight tool having TOO MUCH power).

I can't afford to return or discard the DC and it's quite a pain to turn on and off manually because 9 times out of 10, I forget to turn it on and leave a huge mess.

Thanks in advance!!!


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## Cassandra (Mar 15, 2006)

Hi Steven:

Check the label on the dust collector's motor. Does it indicate that the motor is 120V only or are there ratings for running it on 240V?

A 120V 20A motor will usually take 10A at 240V.

Cassandra


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## BigJimAK (Mar 13, 2009)

Steven,

Cassandra has the most straightforward solution, if the motor is rated for it.

Another option would be to replace the motor with a 15A rated induction motor, recognizing it will be underpowered and may clog if heavily loaded.

An induction motor would technically work if you could use a large enough pulley on the dust collector to get the fan down to the desired speed but the motor wouldn't last very long. Universal motors are designed to provide a lot of power in a small size but are noisy, tend to run hot, and have a much shorter life. A good induction motor has a very long life.

If Cassandra's solution won't work the next best option, IMO, would be to post it on craigslist looking to trade dust collectors with a smaller one.

There is no magic inexpensive solution that I'm aware of.


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## bobj3 (Jan 17, 2006)

Hi Steven


I use the one I have on a 20 amp. outlet but I have a power bar in place (with 5 outlets on it) that's rated at 15 amps. and it runs just fine on that...

Dust Collector - Great Deals on Dust Collectors at Harbor Freight

http://manuals.harborfreight.com/manuals/97000-97999/97869.pdf

to turn it on or off.
H2797 Remote Control - 110V - 75' Range
H5397 220V Remote Dust Collector Switch

But it's not needed  ▼
http://www.amazon.com/BM804-Pocket-...ref=sr_1_1?s=hi&ie=UTF8&qid=1320007455&sr=1-1
http://www.amazon.com/W-Sperry-DSA5...ref=sr_1_6?s=hi&ie=UTF8&qid=1320007455&sr=1-6

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JavaGeek said:


> How can I get a 20 amp dust collector with an induction motor to only use 15 amps? Also, how can I measure how much current I am using?
> 
> I ordered a heavy-duty speed control  from MCS Had 2 questions:
> 
> ...


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## Cherryville Chuck (Sep 28, 2010)

I have a 2 hp DC with induction motor but it came wired for 240v and runs on a 15 amp circuit. If I remember correctly, it pulls 9 amps. If you can switch yours to 240 you only need to put your switch on one hot lead to turn it off and on.


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## Gene Howe (Jul 10, 2007)

I use a remote designed for out door decorative lamps that's rated at 15 amp to turn on my HF DC.
No problems.


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## Relative (Apr 24, 2008)

The surge on the HF is way beyond 15 amps - measured by someone else on another forum at approaching 60 amps or so. Also, the ON/OFF switch is rated at 15 amps and is known to fry after a while - unless HF has addressed this problem in more recent models. 

My switch fried and I removed it completely and use a lamp remote tied to a high capacity relay to turn it on and off remotely. 

Mike


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## xplorx4 (Dec 1, 2008)

My HFDC is rated 20 amps and is not convertible to 240V. I have mine on a dedicated 20amp service with the receptacle at the unit and an isolated 20amp switch in the shop. For a short while I ran the HFDC on the same circuit with my Jet 650 and after 10 or 15 minutes the breaker would trip, I submit that if the HFDC ran at 20amps continually it would have tripped right away, therefore it draws less than 20 amps how much less I do not know. My plan is to run another dedicated circuit for the Jet with a switch in the shop.


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## Relative (Apr 24, 2008)

xplorx4 said:


> My HFDC is rated 20 amps and is not convertible to 240V. I have mine on a dedicated 20amp service with the receptacle at the unit and an isolated 20amp switch in the shop. For a short while I ran the HFDC on the same circuit with my Jet 650 and after 10 or 15 minutes the breaker would trip, I submit that if the HFDC ran at 20amps continually it would have tripped right away, therefore it draws less than 20 amps how much less I do not know. My plan is to run another dedicated circuit for the Jet with a switch in the shop.


Similar experience. Now the HFDC is on its own 20-amp breaker in the shop. What I found when the ON/OFF switch burned up is that it was labeled as a 15A switch but the manual for the HFDC said "120 Volts, 60 Hz, 2HP, Single Phase, 20 AMPS Peak". I located the DC outside the shop in its own cubby and a remote control was the ideal setup. (I used the circuit breaker as the on/off until I put the remote setup in place.)

Mike


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## Relative (Apr 24, 2008)

*Remote circuit reference*

A good reference to build a remote circuit that has a relay large enough to handle just about any tool and also uses the cheap (less than $15) remotes that can be found in the big box stores can be found in this thread on the bt3central forum:

remote-Relay for DC - BT3Central Forums 

The author did a nice job with the schematics for various circuit possibilities, and includes enough instructions for anyone to understand the setup and how to build it - along with some safety warnings.

Mike Cebula


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## BigJimAK (Mar 13, 2009)

"I ordered a heavy-duty speed control from MCS Had 2 questions:
Is there any reason this shouldn't be used with an induction motor (I know nothing about induction motors...is it troublesome to throttle their current?) "

I missed part of your question. No, these universal motor speed controllers cannot be used with an induction motor.


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## RJM (Apr 11, 2010)

Just run it on the 15 amp circuit. More than likely, it will not be an issue. I run my delta 3HP unisaw on a dedicated 15 amp circuit and the only time it tripped was when a bad blade caused a board to bind, stalling the motor. As for the 60 amp peak at startup, this is a very fast transient and is over before the circuitbreaker can respond (in most cases). Unfortunately, the contacts on an underrated switch will "feel" the surge every time and the cumulative effect can eventually lead to a switch failure.

Also, Ivac makes a 115V, 20 amp switch that should work with the same sensing unit.


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## jlord (Nov 16, 2009)

RJM60 said:


> Just run it on the 15 amp circuit. More than likely, it will not be an issue. I run my delta 3HP unisaw on a dedicated 15 amp circuit and the only time it tripped was when a bad blade caused a board to bind, stalling the motor. As for the 60 amp peak at startup, this is a very fast transient and is over before the circuitbreaker can respond (in most cases). Unfortunately, the contacts on an underrated switch will "feel" the surge every time and the cumulative effect can eventually lead to a switch failure.
> 
> Also, Ivac makes a 115V, 20 amp switch that should work with the same sensing unit.


Now I thought that 15amp circuits were usually for lighting circuits & 20 amp circuits were for the outlets. I think if I ran power tools off a 15amp circuit it would put the breaker at maximum rating. I have always been advised to not load the wiring more than 80% of continuous load to avoid overheating the system & tripping breakers.


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## jlord (Nov 16, 2009)

JavaGeek said:


> How can I get a 20 amp dust collector with an induction motor to only use 15 amps? Also, how can I measure how much current I am using?
> 
> I ordered a heavy-duty speed control  from MCS Had 2 questions:
> 
> ...


They sell adapters for the dust collection ports. I use them with the router table. I can use either a shop vac or the larger dust collector hose. Penn State might have something you could use. 

Dust Collection at Penn State Industries

Dust Collection – Rockler – Dust Collectors, Hoses, Attachments, Adaptors, More


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## RJM (Apr 11, 2010)

jlord said:


> Now I thought that 15amp circuits were usually for lighting circuits & 20 amp circuits were for the outlets. I think if I ran power tools off a 15amp circuit it would put the breaker at maximum rating. I have always been advised to not load the wiring more than 80% of continuous load to avoid overheating the system & tripping breakers.


My house was built in 1998 and only my bathroom has a 20 amp breaker for the outlets. The outlets in all other rooms (including the garage and kitchen) are on 15 amp circuits. There are actually 2 bedrooms on a single 15 amp outlet circuit. I wish they were on separate 20 amp circuits. I run my master bedroom window AC off the bathroom to avoid tripping the breaker. Other than that, it hasn't been too much of a problem. With all the electronics, etc. I imagine most new homes are wired with 20 amp circuits on the outlets. if I were building a new house, that's how i'd do it. I'd also have dedicated breakers for specific purposes - like entertainment center, window air, etc. Easy to do when no walls are up.


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## bobj3 (Jan 17, 2006)

Hi

My house was built in the 50's and I updated the service panel about 8 years ago to a 200amp service and replace all the breakers to 20 amp ones all but 3 light circuits, easy stuff to do..

===


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## Cassandra (Mar 15, 2006)

bobj3 said:


> Hi
> 
> My house was built in the 50's and I updated the service panel about 8 years ago to a 200amp service and replace all the breakers to 20 amp ones all but 3 light circuits, easy stuff to do..
> 
> ===


Did you increase the wire size from 14 AWG to 12 AWG? If not, does your insurer know you have increased the risk of fire?

One thing people either don't know or have forgotten is the purpose of the fuse/circuit-breaker panel. The fuse or circuit breaker is there to protect the wiring and wiring devices (like receptacles and wall switches and lamp sockets.) The fuse or circuit breaker is not there to protect the load (what you plug in.) 

Cassandra


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## bobj3 (Jan 17, 2006)

Hi Cassandra

Yes on the 20 amp. circuits but not the light circuits (15 amp) they are still 14 AWG..


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Cassandra said:


> Did you increase the wire size from 14 AWG to 12 AWG? If not, does your insurer know you have increased the risk of fire?
> 
> One thing people either don't know or have forgotten is the purpose of the fuse/circuit-breaker panel. The fuse or circuit breaker is there to protect the wiring and wiring devices (like receptacles and wall switches and lamp sockets.) The fuse or circuit breaker is not there to protect the load (what you plug in.)
> 
> Cassandra


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## RJM (Apr 11, 2010)

bobj3 said:


> Hi
> 
> My house was built in the 50's and I updated the service panel about 8 years ago to a 200amp service and replace all the breakers to 20 amp ones all but 3 light circuits, easy stuff to do..
> 
> ===


I also upgraded to a 200 amp panel. I needed the extra (dedicated) circuits for the (240V) woodworking tools. Tis was easy since both the panel and tools are in the garage; however, upgrading the bedroom circuits would require opening lots of walls and ceilings to upgrade the wiring. Unfortunately, builders save wherever they can and if it's a 15amp circuit, they use 14AWG wire.


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## Vrtigo1 (Nov 1, 2011)

jlord said:


> Now I thought that 15amp circuits were usually for lighting circuits & 20 amp circuits were for the outlets.


It depends on the local building codes. Here in FL it is common for all residential receptacles to be on 15A circuits, but receptacles in a commercial setting will be 20A. Keep in mind that 20A 110V receptacles are different than standard 15A receptacles in that they have both a vertical and horizontal slot for the left prong. Most of the cheap receptacles you can find at home centers will be 15A, and they have a hard time accommodating 12ga wire at the screw terminals and won't accept it at all if you're using the push in terminals.

I have the HF DC as well and am running it on a 15A circuit with no problems.

To answer your question about measuring the load, you could use an ammeter. I have one of the clamp type ammeters which you clamp around the hot wire and it gives you a digital read out of the load. These are relatively inexpensive, and you can often find them at garage sales or on craigslist for next to nothing (I think I paid $5 for mine). Once you have amps, you can also estimate wattage if you had a need to know it. Watts = Volts * Amps. If you also have a voltmeter / multimeter, then you can calculate watts. I distinguish between estimating and calculating because your average electrical service isn't exactly 120V, it's probably something like 115-125V, so you need to know what your voltage is in order to calculate exact wattage, but you can get close by assuming 120V if you can't measure it.


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## JavaGeek (Jul 25, 2010)

Vrtigo1 said:


> To answer your question about measuring the load, you could use an ammeter. I have one of the clamp type ammeters which you clamp around the hot wire and it gives you a digital read out of the load. These are relatively inexpensive, and you can often find them at garage sales or on craigslist for next to nothing (I think I paid $5 for mine). Once you have amps, you can also estimate wattage if you had a need to know it. Watts = Volts * Amps. If you also have a voltmeter / multimeter, then you can calculate watts. I distinguish between estimating and calculating because your average electrical service isn't exactly 120V, it's probably something like 115-125V, so you need to know what your voltage is in order to calculate exact wattage, but you can get close by assuming 120V if you can't measure it.


So I did some research and apparently, you can't just use a clamp-on ammeter on a regular electrical cord (has positive, negative, and ground), right? You need a line separator? 

Every line separator I found is only rated for 15A 

Extech 480172 AC Line Splitter

Otherwise, I would have looked for something along the lines of:
this Craftsman ammeter


Thanks for the responses everyone!

My breaker is rated for 20A, BTW. However, nearly every switching device of every sort is only rated for 15A. At this point, I want to measure how much current my DC is using on startup...just to get a sense of what's going on. 

If I can confirm that the startup power draw is reasonable, say 16A, then I can just buy the expensive iVac Pro switch:
iVac Pro Tool/Switch Wireless Dust Collection Controller System and just run everything on one 20A breaker.

I use my DC with a tablesaw as well, so I wanted to get a sense of how much current is actually being used to see if I need to call an electrician to have another circuit put in.


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## RJM (Apr 11, 2010)

JavaGeek said:


> So I did some research and apparently, you can't just use a clamp-on ammeter on a regular electrical cord (has positive, negative, and ground), right? You need a line separator?
> 
> Every line separator I found is only rated for 15A
> 
> ...


You're way overthinking this. If the HF unit says it needs a 20 amp breaker, then the 20amp Ivac will work fine.


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## Vrtigo1 (Nov 1, 2011)

JavaGeek said:


> So I did some research and apparently, you can't just use a clamp-on ammeter on a regular electrical cord (has positive, negative, and ground), right? You need a line separator?
> 
> Every line separator I found is only rated for 15A
> 
> ...


Well, it's true that to use a clamp on ammeter, you need to clamp around just the hot wire. Probably the easiest way to do that is to determine which circuit it is in your main panel then remove the cover and clamp the wire there, but obviously I wouldn't recommend doing so if you aren't proficient and comfortable working with electricity.

You could also potentially pull the receptacle out of the wall and clamp it there, depending on how much of the outer sheating is stripped off the romex.

You could also make your own line splitter if you were so inclined, just use some stranded 12ga wire to connect a male plug to a female receptacle. Or if you had a short extension cord you can sacrifice you could remove some of the outer sheathing to separate the hot neutral and ground and clamp them there.

The startup load is likely alot more than 16A though. I haven't measured it but from what I gather, motors typically have a start load that is several times their running load, so you could be looking at 50A there. Now, I am getting outside the areas of electricity that I know, but I BELIEVE that circuits and wiring are designed with this in mind. That is to say, that a 12ga circuit which can safely supply 20A continuously can also handle the much higher startup load because it's only for a very brief period of time. But again, I want to reiterate that this is only based on what I've read on other forums, so do your research first before you believe it


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