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

["Markus Lorch" <mlorch vt edu>]

Steve,

thanks for your reply. Let me clarify something:
 
> 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 think I read somewhere that the E20 is a 3-4kw motor which is the power
it can sustain for a longer time. The ICE's are rated at peak power, that
is where the difference comes from. I thus wanted to see what the peak
power of the E20 motor is and, due to the current limiting, that is limited
to the 11 - 14 HP. My question is if this number now is comparable to ICE
HP. 

Do you have a reference for this rule of thumb you mention. I would love 
to 
learn how that comes to be. 
 
> 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. 

Hmm, that is unsettling. I just bought this meter and while it is probably
not
the most accurate meter (meant for automotive testing of alternator and
starter
current draw) I was hoping the readings would be in the right ballpark. 
Well, I'll measure again tonight with the mower motors running on a flat
stretch of the yard and with the meter mounted better, so that I don't have
to bend over and look into the battery compartment while driving in D2!!! 
:)

> Course I haven't taken it to it's limit. I'll have to check it.
> 
Yes, it would be interesting to compare. I'll look at the following:

- driving on level stretch, Speed 4 and Speed 8 in L, D, D2 (while in
motion)
- mowing on level stretch, Speed 4 and Speed 8 in L, D, D2 (while in 
motion)
- start in L, D, D2 on level stretch with full power

Markus