Re: (ET) Motor Question

[Hump <hump evgrin com>]

I've done this with these motors more than once.

If you wired the armature backwards the tractor would run backwards. The 
E-20 reverses the field to control the tractor direction. So if you had 
the arm wired backwards then the tractor would run backwards, since the 
series fields are wired internally.

Here's the easy way to check the arm polarity.

The motor should draw less current in forward than in reverse, since in 
reverse it is fighting the series windings. If it draws less in reverse, 
then BOTH the field and Arm are backwards

But just to have fun....

1. Jack up the rear tires.
2. put shifter in LL, and direction switch in fwd.
3. press foot pedal
4. tires should spin in fwd direction

5. remove field wires from motor
6. press pedal again
7. tires can't possible move in any direction but forward, since the 
series fields are wired internally.

8. reattach field wires.
9. verify proper direction control.
10. remove jack
11. have fun
















Original Message -----------------------


  _____

From: elec-trak-bounces cosmos phy tufts edu
[mailto:elec-trak-bounces cosmos phy tufts edu] On Behalf Of Rob Brockway
Sent: Thursday, November 17, 2005 9:11 AM
To: elec-trak cosmos phy tufts edu
Subject: (ET) Motor Question



I really need some help on this!  Can anyone who has an E-20 confirm the
proper polarity of the armature connections to the drive motor.  I
retrofitted mine and I want to make sure I have the field and armature in
proper polarity.

Rob Brockway, NH


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