S1 & S2 ratings of motors

[Mathurin]

I found a discussion about these ratings on Cyclurba forums.
Thread it came from is here.


This paper says
S1 = continuous power
S2 = temporary service


But right off the bat, the rating for 408's seems low. Aren't these
supposed to be 400w motors that can take a lot more then that?
The 250w BionX seems to match what I would expect to see.
ISD would be the Canadian Tire ebike, btw.

Also, I would expect S2 values to be larger for the clyte 4X then the phantom, because the clyte has 0.5kgs more mass from what I can tell. but these numbers have nothing to do with what I would have expected to see, asides from say BionX. I understand these values have to do with dissipation, mass, insulation heat ratings and mass, right? Where I'm getting at is I don't get it.


Edit: Also I see the nominal rating increases with voltage, but it's not linear . So it would seem more voltage allows somewhat higher nominal output, I take it less wastage?

 

[Mathurin]

from "How To Speak Fluent IEC FOR MOTORS"

Duty cycle

Most NEMA-speakers refer to duty cycle in one of two terms: continuous or intermittent. IEC breaks it into eight ratings:
S1 - Continuous duty. The motor works at constant load for enough time to reach temperature equilibrium.
S2 - Short-time-duty. The motor works at constant load, but not long enough to reach temperature equilibrium, and rest periods are long enough for the motor to reach ambient temperature.
S3 - Intermittent periodic duty. Sequential, identical run and rest cycle with constant load. Temperature equilibrium is never reached. Starting current has little effect on temperature rise.
S4 - Intermittent periodic duty with starting. Sequential, identical start, run and rest cycles with constant load. Temperature equilibrium is never reached, but starting current affects temperature rise.
S5 - Intermittent periodic duty with electric braking. Sequential, identical cycles of starting, running at constant load, electric braking, and rest. Temperature equilibrium is not reached.
S6 - Continuous operation with intermittent load. Sequential, identical cycles of running with constant load and running with no load. No rest period.
S7 - Continuous operation with electric braking. Sequential, identical cycles of starting, running at constant load, and electric braking. No rest period.
S8 - Continuous operation with periodic changes in load and speed. Sequential, identical duty cycles of start, run at constant load and given speed, then run at other constant loads and speeds. No rest.

 

[Ypedal]

*** Les valeurs précédées de ~ ont une possibilité d'erreur lié à des déductions théoriques sur la base des informations fournies par les différents constructeurs***
Il reste de nombreuse intérogations concernant S1, cettes valeurs ne pouvant provenir que de mesures ! Ils sont très rare les kits qui annoncent cette valeur pourtant inpérative pour déterminer si un kit respecte ou non la réglementation !
(*1) la puissance d'un moteur se mesure toujours à la sortie. Toutes les puissances mentionnées ici sont des puissances mécaniques en sortie de moteur. (P=Cw)


Basically they state that the numbers were derived from Theoretical Deductions based on manufacturer specs...

That manufactures rarely state accurate numbers, specially if a kit needs to meet certain legal requirements ( aka UK 200w rules !! )

The numbers represent mechanical output at the wheel

So basically, it's all crunshed numbers derived from spreadsheets and has a large room for + or - lol....

I still need to read the whole thread, but it's late and i'm going to bed.. :wink: