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Re: (ET) Lift wiring



Question 1: are the wires really that small?

That is kind of small, isn't it? I'd say replace with 14 gauge wire. Maybe they were small to help limit lift motor current?

Question 4: to replace that wiring, is it necessary to remove some
batteries?

Route it underneath the tractor, then up through the sides of the contactors into the top and the switch. I'm amazed someone cut the wires that far back.

Remember the concept is this: There are two field windings in the lift motor, one for "forward" and one for "reverse". They go to the two pole ends of the SPDT switch in the console, with the center wire (the one from the armature brush) and the center wire of the switch going to positive battery and negative battery respectively. It's a clever way not to run lots of wires or require a DPDT switch somewhere. Also makes the motor essentially a series wound motor so you can run other voltages on it.

Question 5: would the lift motor be "happy" running on 12v (plow and 
mower)?

Slow as dirt and limited power. Blah. Long ago I decided to heck with it and wired my lift straight to 36 volts. This does not cause the lift to go insane because field current is increased with armature current. It's a series wound motor and people have run those with higher voltages since the beginning of time.

More voltage=less current needed to move along the wire for a given amount of power/lift/oomph. So the wires carry less current, switch carries less current, and the motor bogs down less (which makes it a basic short when stalled).

There's two things to think about:
1) The motor will now be able to lift twice as much as it did on 18 volts and three times what it lifted at 12 volts. If you keep the 30 amp fuse you will have a motor that used to lift windows with 360 watts of power (12*30) and hauling with 540 watts at 18 volts now running with a peak power of 1,080 watts.

That's enough power to rip out the deck lift point if the deck comes up and hits the limit. Enough power to *happily* lift the snowblower in the snow. And enough power that if you DO stall the motor it's going to generate a lot of heat and possibly lift commutator bussbars.

2) The motor does have a thermal/current cut out in there, but those contacts are rated for 12 volts. I don't know if it can open a 36 volt circuit at triple the wattage, but I would wager on those fusing shut. Which means in an emergency situation the lift will probably rip things apart or blow itself up. Hey, bigger power, bigger boom :-)

What *I* do is that I have downrated the fuse to a 20a slow blow fuse. That way the motor is limited to 720 watts with a bit of time to lift really heavy stuff with full force, but if it's stalled the fuse will blow before things get broken.

The net result is more power gets to the motor (as opposed to getting lost in the wiring as heat), more lift power is generated, and the whole thing works great. Occasionally my switch will stick in an up position which just blows the fuse.

Hope this helps. The stock lift motor is surprisingly good.

C

running at

Thanks in advance for any and all info!

Larry Chace  E-15 and I-5




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