reversing a series motor without a reversing contactor?
 

Hello,
I'm in a bit of a pickle. My DCX 300 in my 96 ezgo DCS has bit the biscuit. I have been planning to upgrade the motor and controller to a bigger series motor setup for some time and have ordered all the parts. I have an Alltrax AXE 7245 (series, no plugbrake) and the series motor from D&D should be here tomorrow. Unfortunately it doesn't look like the rest of the goodies, particularly the reversing contactor won't make it here till Monday /Tues and a we have a monster snowstorm coming our way Saturday! I use my cart to snow blow our 400ft road so having it working this weekend is most necessary. I just need to run the cart probably 2 runs up and down our road to clear it however just having forward could get tricky if I get into a place where I can't turn and have deep snow behind me.

So I planning on hopefully improvising something for if I need to reverse. I have a couple sets of Anderson connectors (400 amp) and thinking about some way I could reverse power to the motor field. Having never laid eyes yet on a reversing contactor I don't quite understand the circuit fully and was really hoping someone could answer these questions:

Does the reversing contactor provide power to the armature and only one side of the field coil at a time? Is the other side left open? If so, then could I wire the armature directly to the B+ and switch directions by connecting power to either field pole? Obviously I would have to shut down the main contactor and controller before swapping field poles and I'm honestly hoping to only do this twice (there is a tight spot at end of road)

Thanks in advance for helping a fellow redneck in a tight spot, or literally one come Saturday!

Re: reversing a series motor without a reversing contactor?
 

The difference between Forward and Reverse in a series motor is the direction of current flow in the Stator windings.
(While either way is technically correct, the stationary windings in Series motor are typically called the Stator and in a Sepex motor they are called the Field)

Here is a drawing of a generic series motor set up.
As you see, the Stator current flows from left to right with the F/R switch in one position and from right to left with the F/R switch in the other position.

Basically, current flows A1 -> A2 -> S1 -> S2 for one direction and A1 -> A2 -> S2 -> S1 for the other.

If you can come up with a way to switch the cables connected to S1 & S2, your in the snow blowing business. :thumbup:

Re: reversing a series motor without a reversing contactor?
 

Awesome thanks Johnnie for the diagram & explanation, makes sense now! So all I really need to do is have male connectors on A2 & B+ and female connectors on S1 & S2. To switch directions I will need to shut down the controller and main power, flip the connectors and re-power. Sounds like a pretty sad way to have reverse but likely will be my only choice if I want to use the cart this weekend.

Thanks again!
Dan

Re: reversing a series motor without a reversing contactor?
 

I attached a series cart diagram so anyone coming along at a later date would see what you are saying.

For forward, A2 connects to S1 via the F/R switch and S2 connect to B+ (After the solenoid :mrgreen:)
For reverse, A2 connect to S2 and S1 connect to B+.

Good luck with the snow removal duties. :thumbup: