Centrifugal Start Switch and Drum Switch Retrofit

[Ulma Doctor]

I retrofitted a sinpak centrifugal start switch to my General Electric 1/2hp 1725 rpm 115v motor.

Centrifugal Start Switch Replacement/Retrofit

There are many ways to extend the life of older technologies by retrofitting them with newer technologies. My case is a perfectly functioning GE 1/2 Hp 1725 rpm 115v motor. i savagely harvested the centrifugal start switch, and tossed it aside to make way for a solid state relay made for...

www.hobby-machinist.com

it turned CCW by the OEM wiring.
i one up'd the manufacturer by making it turn both directions by means of an inexpensive 60amp drum switch

60 Amp Drum Switch Forward/Off/Reverse Motor Control Rain-Proof Reversing 60A D | eBay

Wash-down Safe and Rain Proof. 3 Positions: Forward, Stop, Reverse. Switch Action: Maintained (Stay Switched).

www.ebay.com

i first pinned out the drum switch


then i came up with the wiring diagram



T5 and T8 are the start winding ends.
when you reverse T5 and T8 the motor will turn the opposite direction,
given that the neutral and capacitor lead are also reversed in conjunction with T5 and T8.

i extended 4 leads out from the motor to hook to the drum switch for directional control.
i added incoming power and tested the motor.
with pride i can report, the motor turns both directions!

i made a video of the motor test and an explanation of the wiring.
if you have nothing better to do for the next 5:13 have a look!

as always thanks for reading and watching!

 

[Aukai]

So you drew these up tomorrow?
It's an electrical diagram, and the smoke has not been let out yet. That's all I got

 

[Ulma Doctor]

So you drew these up tomorrow?
It's an electrical diagram, and the smoke has not been let out yet. That's all I got

I’m not even sure how i got my date wrong!
i musta been thinking about something else at the moment i was writing the date.

although the date is wrong, the rest of the information should be accurate.

 

[rb67mustang]

Hi, Ulma Doctor,
I'm a retired Machinist with nowhere near your ability in electrical. I recently bought an old & used Bridgeport that I'm converting to single phase. It's for personal hobby use and I don't have 3 phase power coming into my house. I have a new 1.5 HP motor with dual capacitors and there are 9 wires numbered T1 to T9.

The wiring diagram for one-way rotation shows three wires (T1, T3, T8) bundled together as line #2, and line # 1 is attached to T5, and there's a screw to attach the ground.

I have the same exact drum switch you're using. If I follow the diagram inside the drum switch cover and I wire nut the unused motor wires together I think I'll be OK. I know I sound like I'm not an electrician. My Dad when he was living would have wired this for me with his eyes closed. I just don't want to destroy my new motor or get zapped in the process.

I appreciate any help you can give me.

 

[rb67mustang]

BTW, I watched your youtube video, and that brought me here and I joined the group. I'm hoping to be able to help out members with their machining projects, and see what everyone's doing here.

 

[Ulma Doctor]

I just saw your reply
I’m hitting the rack in a minute, but i’d be happy to look over your issues in the morning

 

[rb67mustang]

I just saw your reply
I’m hitting the rack in a minute, but i’d be happy to look over your issues in the morning

Thank you very much.

One more question? When looking at the wiring diagram inside the switch cover, how does one know what end the wires come into the switch, and what end is the handle to operate the switch? The cover fits either way. So, looking at the orientation of your drum switch in your video, how would it be wired?

Please forgive me, as I mentioned, I'm not an electrician, I only know enough to get myself in trouble. Adding new circuit breakers and wiring a new receptacle or light switch is easy to do after watching a couple of videos on YouTube. Wiring my motor/drum switch, not as easy to understand from the videos I've watched.

Thanks again, Ulma DR.

 

[Ulma Doctor]

Were you interested in having the motor reverse directions?
What voltage are you planning on using?

 

[rb67mustang]

Yes, forward and reverse like all Bridgeport milling machines. Single phase 110/115 volts.

 

[rb67mustang]

Your wiring diagram is awesome, but its not easily undersranded by non-electricians. Maybe a photo or two showing the wires marked by number. Then anyone could wire this drum switch knowing its correctly done.