# DMOC645 - differences in water cooled vs air cooled?



## The_Sasquatch (Feb 11, 2018)

First, new to the forum, thanks everyone for creating such a great resource! 


My question is: what are the differences(other than the obvious:cooling scheme) between the air and water cooled versions of the dmoc645 controller? Given that it seems like there are several methods to reprogram the air cooled version to think it's water cooled, and the price difference between the two versions, the air cooled version seems like an obvious choice if it can be cooled sufficiently... Are there internal component differences or other drawbacks that I don't know about?


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## The_Sasquatch (Feb 11, 2018)

I should add, I did find the following possible answer to my question, but given that it is 3 years old, I am still curious if anything more recent has been learned.


QUOTE=electricmini;646674]Ok, just for info, I've looked inside the air-cooled DMOC 645 that I've just got from Brian, and it's insides appear to be *identical* to the liquid cooled version from the Transit Connects.
(I have a set of working boards from a liquid cooled unit here as well)

Same CPU & interface boards
Same gate driver board
Same IGBTs
Same heatsink temperature sensors
Same internal wiring

The only difference I can see is the heatsink itself (and the labels!), and possibly the data in the .ccs or .par files for the heatsink's degC/Watt values, used by the DMOC to estimate the IGBT junction temperatures

And yes, it can be flashed using the TCBEV software programs
I've loaded in the profile for the AZD Siemens 1PV5135 motor

NOTE: I haven't _*run*_ a motor yet with the air-cooled DMOC - that'll happen in the next couple of days ( a Ford Ranger/Siemens unit)

It's strange how the DMOCs appear to support automatically switching on a fan when a temperature threshold is reached - the relay and connectors
are present & working on the pcbs, they just didn't bother connecting them up to the Ampseal23 connector.
I guess you can just get the temperature from the CAN data the controller spits out[/QUOTE]


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## Kevin Sharpe (Jul 4, 2011)

The_Sasquatch said:


> Are there internal component differences or other drawbacks that I don't know about?


I think they are identical... Wolf would know for sure... look up his video series on reprogramming the DMOC645


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## CKidder (Dec 12, 2009)

The two are identical except for the heatsink arrangement. I've successfully spun motors with the air cooled version. Once you tell it that it's liquid cooled it's perfectly happy to run just the same as the liquid cooled version.

So, the only real drawback is that the air cooled version is likely to overheat more easily. But, with proper air flow it won't.

Oh, and the air cooled version has downed power lines for cabling. It's like double aught 2/0 wire with triple insulation. It's a pain to work with.


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## The_Sasquatch (Feb 11, 2018)

Thanks for the responses. How bad are the cables on the air cooled version... What would you estimate on the minimum bend radius? Is it replaceable?


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