DPDT ac/dc switch

RocketQ

It's Not Rocket Science
Silver Member
Any one know if you can use a DPDT ac switch on dc to reverse a dc motor?
As long as the voltages and amps are within the switches limits.
 
RocketQ said:
Any one know if you can use a DPDT ac switch on dc to reverse a dc motor?
As long as the voltages and amps are within the switches limits.

If you are switching the DC voltage, one throw this-a-way and the other throw that-a-way, I don't see why not. Just be very careful about the ratings as many switches have much higher ratings for AC than for DC.

Also be very very careful not to flip the switch from one 'direction' to the other when the motor is running ... you could let the smoke out and as we all know, things do not work after the smoke has escaped.

If you are switching AC then no, it won't work.

Dave
 
Hi John,
I'm going to say no. There aren't enough lugs on the switch for one. Also it doesn't provide for crossing circuits. There are inexpensive reversing switches available but their cost will be dependent on application and the load they'll control. Some DC mtrs. aren't reversible. Have you confirmed that yours is? KJ

Addendum : I was just thinking further on this and need to ask, is it a 3 position switch, with 6 lugs and with 'cntr.' off? If it is this type of switch, then yes, it will work.
 
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It must be an on-off-on style dpdt.
Also, some dc motors don't like to change direction. You might test that manually before going to too much trouble.
 
KJ Cues said:
Addendum : I was just thinking further on this and need to ask, is it a 3 position switch, with 6 lugs and with 'cntr.' off? If it is this type of switch, then yes, it will work.

The "DP" means Double Pole, so it switches two leads. The "DT" means Double Throw, so it can be wired up with one throw one way and the other throw the other way ( +- and -+ ). There should be 6 lugs on a DPDT switch. dchristal makes a fine point that the switch must also be an on-off-on style (you can get on-on style DPDT, and momentary-off-on configurations, etc.)

Dave
 
RocketQ said:
Any one know if you can use a DPDT ac switch on dc to reverse a dc motor? As long as the voltages and amps are within the switches limits.


John, if it is something like what you get at an automotive store, it will work fine. It is your choice if you want one with an "OFF" position in the center. Just do not switch it while the motor is running.

If you need a schematic on how to wire it, I can email you one.
 
WilleeCue said:
John, if it is something like what you get at an automotive store, it will work fine. It is your choice if you want one with an "OFF" position in the center. Just do not switch it while the motor is running.

If you need a schematic on how to wire it, I can email you one.
Sorry for the delay guys. Yes 6 poles cntr is off. Motor is reversible. Load of switch is 125vac 6 amps and I am running 90 vdc .5 amps. From what I can see the 2 cntr poles go to the motor and the outter 4 go to the power source. All I have to do then is flip the pos and neg to wire it up. Radio shack had the switch but there is no diagram or schematic for the poles on the switch.

+ | -to motor | -
- | +to motor | +

Thanks for the help...
 
RocketQ said:
Sorry for the delay guys. Yes 6 poles cntr is off. Motor is reversible. Load of switch is 125vac 6 amps and I am running 90 vdc .5 amps. From what I can see the 2 cntr poles go to the motor and the outter 4 go to the power source.

The four outer poles are connected with wire to make like an X and one set is wired to the power + and -.
The center set of poles go to the motor as you stated.
This reverses the power to the motor when you throw the switch.
I think you got a good handle on it but if you need help let me know.
 
On AC motors you normally need a three pole double throw switch as you have more to switch than just the positve and negative. But with most DC motors you only need to switch the positve and negative.
To wire a double pole double throw switch for normal DC motors you hook the wires from the controller with the hot up to one middle pole and ground up to the other middle pole. You hook up the motor hot and ground to one end side by side. But now you make two short jumper wires and hook to the same lugs you just hooked motor hot and ground to. Then jump them over to the other end, but cross them like an X over to the lugs on the other end. Now it will work forward or reverse. If you throw this thing in reverse with it running forward, usually you will burn your motor up or blow out the controller.
 
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tsp&b said:
YES It will work the same for dc as for ac....:)

Most AC mtrs. are NOT reversible unless they're 3 phase, in which case, swapping any of the 3 'hot' leads will cause the mtr. to run in reverse.

As far as wiring the DPDT switch to control a DC mtr., Chris's method is spot-on. It's the simplest, cleanest method for crossing the circuits externally.
 
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not reverseable ?

In Chris Hightowers video i see him reversing the a/c motor several times without stopping it . i am assuming the motor on the deluxe is a/c also.
i would like to add a switch to my midsize in the recipticle that the variable speed switch is located.

carl
 
nympfisher said:
In Chris Hightowers video i see him reversing the a/c motor several times without stopping it .

You can certainly do it, the question is "how many times ?" ... it is rough on the motor (and motor drive) and typically not recommended.

Dave
 
nympfisher said:
In Chris Hightowers video i see him reversing the a/c motor several times without stopping it . i am assuming the motor on the deluxe is a/c also.
i would like to add a switch to my midsize in the recipticle that the variable speed switch is located.

carl

I doubt very seriously if the Hightower machines use a reversible A/C motor. A/C reversible variable speed motors are very expensive and must come to a complete stop before the reversing switch can be thrown. Most of these smaller, lightweight motors are what are called Universal motors that use A/C current but the motor is actually a D/C motor. Drills, routers, sewing machine motors and such are actually Universal motors.

Dick
 
nympfisher said:
In Chris Hightowers video i see him reversing the a/c motor several times without stopping it . i am assuming the motor on the deluxe is a/c also.
i would like to add a switch to my midsize in the recipticle that the variable speed switch is located.

carl
I thought I always stop my lathe before reversing it. So if someone like me who tries to stop before reversing a AC motor slips up and reverses before stopping. You can see why I don't put a reverse switch on a those Mid Size DC motors. One throw in reverse on that DC motor while running forward and you burn up the motor. If you install a reversing swith your motor and controller are no longer under warranty.
 
rhncue said:
I doubt very seriously if the Hightower machines use a reversible A/C motor. A/C reversible variable speed motors are very expensive and must come to a complete stop before the reversing switch can be thrown. Most of these smaller, lightweight motors are what are called Universal motors that use A/C current but the motor is actually a D/C motor. Drills, routers, sewing machine motors and such are actually Universal motors.

Dick
You really should stop in and see one of my lathes sometime in person. I will give you a tour if you ever head to Florida or come by my Expo booths. I am only about 1/2 hour off of I-75. So to satisfy your doubts. Yes, I do have a 110 volt reversing AC motor on my Deluxe Cue makers lathes. My AC motor is not variable speed but believe it or not they are reversible. Simple switch with only about 20 total wire connections to make it do so. :)
 
cueman said:
You really should stop in and see one of my lathes sometime in person. I will give you a tour if you ever head to Florida or come by my Expo booths. I am only about 1/2 hour off of I-75. So to satisfy your doubts. Yes, I do have a 110 volt reversing AC motor on my Deluxe Cue makers lathes. My AC motor is not variable speed but believe it or not they are reversible. Simple switch with only about 20 total wire connections to make it do so. :)

I never go to Fl. but if I ever run into you at a show of some kind I'll definitely take you up on your offer. The reason for my comment was from the information that Nymphfisher made in the twelfth comment, about seeing you reversing your motor without stopping first. This can be done on universal motors but not normally on standard A/C motors that use a capacitor starter as the motor will continue in the same direction.

Dick
 
oops

i see now that the motor is d/c , didnt notice that before i posted. just assumed it was the same as the deluxe , although it is very obvious that the motor is bigger , just assumed it was a/c. and to have a variable speed on ac requires and expensive vac unit..

i stand corrected...

carl
 
rhncue said:
I never go to Fl. but if I ever run into you at a show of some kind I'll definitely take you up on your offer. The reason for my comment was from the information that Nymphfisher made in the twelfth comment, about seeing you reversing your motor without stopping first. This can be done on universal motors but not normally on standard A/C motors that use a capacitor starter as the motor will continue in the same direction.

Dick
You are right, unless I allow the motor to slow way down before hitting reverse it will continue running forward. So I always try to let it stop first. It might be possible I am breaking the motor with one hand grabbing the wood then hitting the reverse the instant I force brake it. I really can't remember what was being referred to in my video.
 
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Unique's ac motor with Minarik controller is somehow reversible.:confused:
http://www.distel.co.uk/DC_MOT_CON1.htm
I dunno if that helps.
 
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