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Re: (ET) E20 main motor rating / max amperage



I believe the rule of thumb is 1 electric HP compares to about 4 ICE HP. I think the '20' in the E20 is meant to compare the E20 to a 20 HP ICE tractor - it is not a 20HP electric motor.

I'm surpised at your current readings. My ammeter (150A max hall effect probe) usually runs around 30-40 A in flat mowing (traction motor and mower motors combined). I've never seen it run over 60 A or so total. Course I haven't taken it to it's limit. I'll have to check it.

- SteveS
E20



Markus Lorch wrote:

Hi all,

I've got me an inductive ammeter for DC amps and did some measurements driving around my stock E20 yesterday. I noticed that the traction motor draws around 50 Amps when driving in L, Speed 4 on a slight incline.
Then I tried to push it to the current limit by flooring the pedal when
in D2. If my measurements were right (it was bumpy!) then the current
limiting circuit turns of field weakening at around 300 Amps !! that's
an impressive amount of power (10.8kw). This would be the equivalent
of 14.5HP of power consumption. Assuming a motor efficiency of about 80% (just a figure I picked, I have no idea how efficient that motor really is) that would give me something like 11.5HP output. Can I compare this number to the power rating of gas engines? I understand they are rated at peak power and this the 11 - 14 HP seem to be the max the E20 traction motor can provide due to the current limiting. Can anybody tell me if I am in the right ballpark? This number is quite a bit off of the 20HP rating that I assumed the "E20" stands for. How did they calculate. I remember an old post about them comparing available torque but can't find it in the archive.
I understand that a gas engine would not give me its max power at 
standstill

or low rpm. I would probably burn up the clutch/belt if I tried to get 14HP
transmitted from an ICE to the tranny in a high gear or stall the ICE.
Markus


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