# Temperature sensor for a Warp9 to turn on fans



## evsource (Mar 23, 2009)

Hi Corbin,



corbin said:


> Hi all,
> I'm looking for a temperature sensor to turn on fans to cool my Warp9 motor. Any recommendations for a sensor and fans?
> 
> corbin


Of course there is the internal temperature snap switch, but the motor is too hot when that kicks in (120C on the WarP 9). 

For drag racing, these suggestions might not hold, but for a daily driver, I would probably keep it simple for deciding when to turn the air cooling on or off. Possibly a circuit monitoring the air temperature from the exhaust side (drive) of the motor from the internal fan. If it gets above a certain temperature, kick the forced air cooling on. Make sure to have some hysteresis, so the blower isn't kicking on an off right around the setpoint.

To get a little more complex, I would probably build a circuit that read the controller data (you have a WarP-Drive, right?) on the CANbus, and pulse width modulate the blower motor to give an air speed proportional to the load (since the temperature should correlate pretty closely to the current flow through the motor). That would be the cat's meow in my opinion. If there was enough interest in such a module, I could talk with NetGain to possibly build it. I've heard them talk about it before. What sort of price would you expect for something like that?

The really simple way is to just run the blower all the time when the controller is on. We carry blower kits:

http://www.evsource.com/tls_motor_cooling.php

You want a squirrel cage blower to get some volume through the motor.


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## Tesseract (Sep 27, 2008)

corbin said:


> Hi all,
> I'm looking for a temperature sensor to turn on fans to cool my Warp9 motor. Any recommendations for a sensor and fans?
> 
> corbin


I wouldn't overthink this too much - motors have very long time constants w/r/t temperature vs. current so I would either have the blower turn on with the ignition or use a bimetallic snap switch to control an automotive relay that controls the blower.

34-42C NO Temperature Switch

40A Automotive Relay

Rebirth Auto has had good success with bilge blowers from West Marine. You need something that can work against a bit of back pressure because the motor internals present a lot of obstructions to airflow.


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## evsource (Mar 23, 2009)

Tesseract said:


> I wouldn't overthink this too much - motors have very long time constants w/r/t temperature vs. current so I would either have the blower turn on with the ignition or use a bimetallic snap switch to control an automotive relay that controls the blower.


I'm going to get in trouble for this comment, but I have to poke a little fun. Isn't this coming from the person that's destroyed 7 motors?! 

Really though, thanks for the parts suggestions. That would be the simple, yet intelligent way to turn the blower on.


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## Tesseract (Sep 27, 2008)

evsource said:


> I'm going to get in trouble for this comment, but I have to poke a little fun. Isn't this coming from the person that's destroyed 7 motors?!
> 
> Really though, thanks for the parts suggestions. That would be the simple, yet intelligent way to turn the blower on.


Believe it or not, I'm actually the very model of reason and caution compared to Seb... he's personally responsible for destroying four WarP-9s and a Kostov 9 (the other two are the ones we know about from our customers, one of which was a WarP-11 and the other I can't remember, maybe an ADC 9"?)

Anyway, we found that the commutator seems to get hotter faster than the field in the WarP-9, but I think the internal temperature switch on the motors is embedded in the field. If you are mildly overloading the motor the temp switch might catch it, but severe overloads lasting more than 30 seconds but less than, say, a couple of minutes will destroy the commutator before the temp switch trips.

Oh, and you are most welcome for the parts suggestion.


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## DIYguy (Sep 18, 2008)

The 13 inch I currently have apart, has a snap switch with a spring behind it pushing it up against the back of one of the field coils. This is through a hole in the frame...with a little screw-held plate to contain it.


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## corbin (Apr 6, 2010)

Jeffrey and EVSource, thank you both for the information and parts recommendations!

EVSource -- I have been eyeing your blower kit; it is quite nice! The idea of tying into the Warp Drive controller is AWESOME! I'm slowly building up my EE knowledge so I can eventually do things like that. Until then, I may take Jeffrey's suggestion and use a simple temp switch.

Does anyone have any real-world temperature values for when to turn on and off a blower on the Warp9?

corbin


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## lowcrawler (Jun 27, 2011)

Corbin, did you ever get any answers to your last question?


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## corbin (Apr 6, 2010)

lowcrawler said:


> Corbin, did you ever get any answers to your last question?


No, I didn't! I'm still not using a blower on my motor, even though it gets *quite* hot (if I recall off the top of my head 70-90C). The temperatures should be well below the max rated temperature, so I'm assuming it is okay. Sure, a colder motor is better and will probably last longer.

corbin


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## piotrsko (Dec 9, 2007)

left handed thought: why not use the controller fans to cycle the motor fan? if the controller is getting hot enough to require cooling, ought not the motor need it also? Obviously there needs to be some sort of temp offset/differential, but linear is linear.

Oh yeah, I have a SOL1, but the theory of using the controller temp still should work.


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## Hollie Maea (Dec 9, 2009)

http://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Encoders/Temperature_Sensors/Temperature_Switches/TSD25N-0P-0284-H

Expensive, but this looks like a pretty sweet switch.


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## GizmoEV (Nov 28, 2009)

I know this thread started a long time ago but I thought I'd post what I did with my 6.7" SepEX motor. It might apply somewhat to a Warp9 if it isn't severely overloaded like Jeffery was saying. I installed a small snap switch like Jeffery suggested. I figured that having a 100°F (~38°C) turn-on point might just be soon enough that the internal temp wouldn't be too high. I also figured that if the ambient temp was high enough that the fan came on right away that it would be better for the motor any way. Besides, with a bilge blower supposed to last 1000 hours I figured I could put on well over 25,000 miles before the blower quit and I had to replace it.

I did install an on-off-on switch in the dash with a red LED which lights when the snap switch is closed and the toggle switch is in the off position just in case the fan got left off. I rely on the coil through the relay to power the LED. I first tried a small incandescent bulb but the resistance was too low and the relay would be pulled in by the bulb.


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## lowcrawler (Jun 27, 2011)

The warp9 comes with a snap sensor snap switch that triggers at a level well below the max operating temps. (120 or 150 if I remember right) .... why not just use that?


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## O'Zeeke (Mar 9, 2008)

lowcrawler said:


> The warp9 comes with a snap sensor snap switch that triggers at a level well below the max operating temps. (120 or 150 if I remember right) .... why not just use that?




See #5 above


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