Outlet will turn on vacuum when it's on Auto mode

Merry Christmas

Jordan_

Member
Location
Los angeles
Occupation
Contractor
Hello. Something strange happened. I have a vacuum in my shop, that has an "auto mode" which will turn the vacuum on every time I pull the trigger of the tool that is plugged to the vacuum (it has an outlet on it). It works perfectly fine except when the vacuum itself plugged to outlets on a particular line at the shop when it will turn on and stay on even when the tool is not in use.

Any Ideas?

Thank al lot!
 
Last edited:

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I assume a signal is sent thru the cord to the unit. If you insert the cord other than into the saw outlet then it will not work.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Hello. Something strange happened. I have a vacuum in my shop, that has an "auto mode" which will turn the vacuum on every time I pull the trigger of the tool that is plugged to the vacuum (it has an outlet on it). It works perfectly fine except when the vacuum itself plugged to outlets on a particular line at the shop when it will turn on and stay on even when the tool is not in use.

Any Ideas?

Thank al lot!
So, it works fine if it's plugged into some receptacles, but the problem only shows up on other receptacles? I would start by looking for a voltage drop on the problematic receptacles.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
That method of controlling a dust collector or vacuum has been around for ages. I always assumed that the receptacle on the vacuum that the saw or sander plugs into is just looking for a current draw. When it sees it the vacuum turns on.

Unfortunately engineers can't leave well enough alone and probably designed it down to nothing to save pennies. Betcha there is a standard chip for that application. My guess is that there is noise on that circuit that is triggering the piece of junk.

I assume this happens with no tool plugged into the vacuum receptacle?

-Hal
 

Jordan_

Member
Location
Los angeles
Occupation
Contractor
That method of controlling a dust collector or vacuum has been around for ages. I always assumed that the receptacle on the vacuum that the saw or sander plugs into is just looking for a current draw. When it sees it the vacuum turns on.

Unfortunately engineers can't leave well enough alone and probably designed it down to nothing to save pennies. Betcha there is a standard chip for that application. My guess is that there is noise on that circuit that is triggering the piece of junk.

I assume this happens with no tool plugged into the vacuum receptacle?

-Hal

I played with the vacuum a little bit now and it actually happens only when I plug two tools into the vacuum. when only one tool is plugged in or no tool at all it seems to be working ok
 

tom baker

First Chief Moderator
Staff member
That method of controlling a dust collector or vacuum has been around for ages. I always assumed that the receptacle on the vacuum that the saw or sander plugs into is just looking for a current draw. When it sees it the vacuum turns on.

Unfortunately engineers can't leave well enough alone and probably designed it down to nothing to save pennies. Betcha there is a standard chip for that application. My guess is that there is noise on that circuit that is triggering the piece of junk.

I assume this happens with no tool plugged into the vacuum receptacle?

-Hal
Now Hal you are being a bit of a Luddite, and I agree with you!
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I played with the vacuum a little bit now and it actually happens only when I plug two tools into the vacuum. when only one tool is plugged in or no tool at all it seems to be working ok

Probably there is enough leakage from L-N when both tools are plugged in to make the vacuum current sensor think a tool is turned on. At the same time, it might also be that the voltage is a little high on that circuit making the leakage current slightly higher and enough to trigger the control just on that circuit.

All-in-all I would say it's a defective or off tolerance current sense control in the vacuum. I would think it should be looking for a couple of amps before triggering, no less.

-Hal
 

acin

Senior Member
Location
pacific grove california
Occupation
general building contractor est.1984 . C 10 elec. lic.as of 8 / 7/ 2020
So, it works fine if it's plugged into some receptacles, but the problem only shows up on other receptacles? I would start by looking for a voltage drop on the problematic receptacles.
Hot / neutral polarity issue at receptacle or cords??
 

Jordan_

Member
Location
Los angeles
Occupation
Contractor
Probably there is enough leakage from L-N when both tools are plugged in to make the vacuum current sensor think a tool is turned on. At the same time, it might also be that the voltage is a little high on that circuit making the leakage current slightly higher and enough to trigger the control just on that circuit.

All-in-all I would say it's a defective or off tolerance current sense control in the vacuum. I would think it should be looking for a couple of amps before triggering, no less.

-Hal

I plugged into another outlet on the same line a small space heater and it solved the problem! any better Idea how to lower the voltage?
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
We don't know for sure if that is what's causing the problem. What we do know for sure is that the vacuum is defective. Who makes it, how old is it and can you return it or get it repaired. That's what I would be looking at.

-Hal
 
Top