RE: (ET) Dead on the road

["Markus Lorch" <mlorch vt edu>]

Bob,

the first thing I check if my motor doesn't move or only 
moves a little bit is if I still have the main motor field. 
A missing field is typically indicated by the armature drawing
excessive current while the motor barely moves (the small series
field on this compound motor may give it enough field strength
to move a little bit). The power use gauge will show high power
levels (just try this briefly).

If this is the case, then I would go and check the diodes on card 4,
the ones to the right bottom of the card (bottom being where the 
connector is) on my CC and BA model tractors are responsible for
providing the field current in the same direction independent of
the armature current flow direction. They broke on both my tractors
and I replaced them with large rectifier diodes (I think rated 6A)
from RadioShack (which I think is overkill, but thats what they
had in the store).

I don't have my schematics at hand right now, hope this helps.

Am still investigating why my own speed 8 doesn't work :)

Good luck

Markus


> -----Original Message-----
> From: elec-trak-bounces cosmos phy tufts edu 
> [mailto:elec-trak-bounces cosmos phy tufts edu] On Behalf Of 
> Klein Robert W NPRI
> Sent: Donnerstag, 27. Januar 2005 08:48
> To: 'Chris Zach'; Elec-trak list
> Subject: (ET) Dead on the road
> 
> 
> First let me say that I've never been so impressed with my 
> Wheelhorse C-185 (E-20) then during this last two snow dumps 
> here in New England.  The combination of snowthrower for 
> removal of the high volumn light and fluffy coupled with the 
> quick change to the plow for the removal of hardpack on 
> pavement has impressed the entire neighborhood.
> 
> Now for the bad news...  One of my favorite neighbors missed 
> all this blizzard action by being in Hawaii on vacation (Talk 
> about timing ).  Being the good simaritan, I fired up the 
> snowthrower and headed off to make sure he had a way to get 
> in his driveway and into the house.  This entailed the 
> removal of 4-5' high snow drifts over a loose gravel 
> driveway.  After two hours I had removed a car width of snow 
> 75' long as well as hand shoveled his walk, stairs, and front 
> porch.  Fully exhausted I backed out and did a couple of 
> passes in front of the mailbox.  It was at this time that I 
> pushed into a pile of snow left from the plow, the engine and 
> blower motor loaded down big time.  By the time I removed my 
> foot from the pedal all was quiet.  The I figured I had over  
> heated the motor so gave it a 20 minute rest... But the motor 
> was only warm to the touch.  Physically disconnected the 
> snowblower.  Checked the fuses and 50amp circuit breaker... 
> All OK.  Walked home, got my IC Wheelhorse and
> with the help of another neighbor towed the C-185 (E-20) back 
> home.  Put the charger on.  Pulled the thermal circuit 
> breaker off the motor and checked with a VOM meter... 
> Everything OK.  Put the transmission in neutral and pushed 
> the throttle pedal and the motor barely moved... Like it 
> wasn't getting any real power.  
> 
> The front lift vcontinues to work fine.  No smoke or smell of 
> burning wires.
> 
> HELP!  Could it be that I've fried a contactor/solenoid?
> 
> Bob Klein
> Really Snowbound in Charlestown, RI
> 
> 
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