The article made me cringe. Why do they always add the word "continuous", as in maximum continuous rated power? In that context, continuous has no meaning, as the rating of the motor can't change, so it's always continuous. It's the same as saying the continuous colour of the front light needs to be white or the continuous brakes must work.Dutch Police seem to have a gadget for testing speed under load:
View attachment 57452
Article here:
Police roadside test uncovers illegal e-bikes | ETA
Dutch police have unveiled a new roadside device for testing whether e-bikes comply with the law. The mobile rolling road test benches can assess...www.eta.co.uk
Fine is €250 which is rather more lenient than having your bike taken away.
De restrict for off road use
- Thread starter Monkeyman661
- Start date
It's what the laws say that they are repeating:
From the original EAPC law of 1983:
2. In these Regulations—
“continuous rated output” has the same meaning as in the 1971 British Standard;
And from the Two and Three Wheeled Type Approval law exemption for EAPCs:
(h) pedal cycles with pedal assistance which are equipped with
an auxiliary electric motor having a maximum continuous
rated power of less than or equal to 250 W, where the
output of the motor is cut off when the cyclist stops
pedalling and is otherwise progressively reduced and
finally cut off before the vehicle speed reaches 25 km/h.
.
I thought it meant max power in thermal equilibrium, as opposed to a peak power that would eventually cause the motor to overheat (critically the regs don't specify the speed :- just about any motor would overheat at 250 watts if it's going slow enough)
Aye but in the context of bikes motors
In machinery, continuous rating is more about its heavy duty so can be in operation all day, every day, for years.
Hobby rated, where the machine is going to be switched on for under 30 mins, or trade/industrial rated where the machine gets switched on at 8am and either switched off at 5pm or in some big industry operation only gets switched off for maintenance.
Just being pedantic.... sorry
D
Deleted member 16246
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You have continuous power, maximum continuous power and rated power. Rated power is the maximum continuos power with an added safety margin, which is whatever the engineer decides is necessary. There is no such thing as thermal equilibrium for an electric motor because it changes with speed. When they test that a motor complies with its rating, they first determine the RPM for optimal efficiency, then test it at that RPM. In that case a motor would overheat if it's max continuous power was the same as its rated power because at any other RPM, it would produce more heat and thus exceed thermal equilibrium.
As I said, the term " continuous rated power" has no meaning. They could just as well write it as the "always rated power" or the "written in the specification rated power" because the rated power can never change.
In the context of an ebike, a motor in a hub can run with an efficiency of around 75% at 15 mph, but when climbing a hill, its efficiency can drop to 30% or lower, when it's producimg nearly three times the heat as it was at 15 mph. The maximum continuous power is tested at the equivalent of 15mph.
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That's slower than you ?
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