# Thermal sensor in Huari scooter motor



## Quackerback (Aug 15, 2011)

I have a Huari scooter with a 4000 watt hub motor that died all of a sudden when doing 55 on a freeway. I discovered that the breaker was thrown but when I reset it, the motor ran very rough and wouldn't go past 20 mph. I managed to get home but it soon quit altogether. I pulled the hub and took it to a friend with lots of experience working with hub motors. He tested the hall sensors and they all appear to be fine. When he tested what appears to be a thermal sensor, it was open (no continuity). So my question: Does this motor in fact have a thermal sensor and what is its normal state, open or closed?

One of the wires was also black so that could be an indication of a problem, but he did not think that would cause the motor to quit entirely. We have not tested the controller but as this scooter came with no documentation, he was not sure how to go about testing it.

I'll attach a picture of the suspect wiring and of what we think is the thermal sensor (white rectangle in the middle with 2 white wires).


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## Ektus (Feb 15, 2011)

Quackerback said:


> I'll attach a picture of the suspect wiring and of what we think is the thermal sensor (white rectangle in the middle with 2 white wires).


The thermal sensor could be a thermal switch also, which may be either NC or NO. You could easily test it with a heat gun.


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## Quackerback (Aug 15, 2011)

> The thermal sensor could be a thermal switch also, which may be either NC or NO. You could easily test it with a heat gun.


Not sure what a heat gun is. Will a 1500 watt hair dryer do the trick?


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## Ektus (Feb 15, 2011)

Quackerback said:


> Not sure what a heat gun is. Will a 1500 watt hair dryer do the trick?


It might not get hot enough, as it should be designed not to burn your hair 


Search for "heat gun" on amazon.com, I'd go for something like http://www.amazon.com/Porter-Cable-...UTF8&qid=1342368553&sr=8-17&keywords=heat+gun which has a variable temperature setting. The heat switch might activate anywhere between 60°C and 120°C, you'd have to check the data sheet if there's no temperature indicated on the device (and if it's a switch at all).

For testing, and as it currently has no continuity, you could simply short the sensor and see if it makes any difference.


With best regards
Ektus.


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## Quackerback (Aug 15, 2011)

Ektus said:


> The heat switch might activate anywhere between 60°C and 120°C, you'd have to check the data sheet if there's no temperature indicated on the device (and if it's a switch at all).


Data sheet? I could only dream of such a luxury! This scooter came with diddly squat, the seller is out of business and I've yet to find anything on the manufacturer (Huari) that is of any help.

I did get the motor running again though using a different controller, so evidently the heat switch is working fine.


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