Safe Temperature Operating Ranges For A DDEC ECM

Fernando DeMoura
April 2020

I’ve got a toddler who likes pushing buttons and if it’s a glowing button, a button on a touch screen display or a button that controls a TV that’s even better. What better way to learn what that button does then to push it right? That’s all well and good but eventually that stuff needs to be put some place where her little hands can’t get to them. It’s been a while since I shopped for furniture let alone a TV entertainment stand. I took a 4 inch hole saw to the back of the last entertainment stand I bought because the stereo receiver kept overheating and I needed to get more air in and out of the cabinet.  The guys who designed that stand didn’t think much about the cooling needs of the electronics that stand was designed to hold. By the looks of it things are even worse these days. Some of these TV stands have a built in electronic heater that looks like a fireplace. If your house is so cold that you need a heater to prevent the electronics from being damaged, then keeping the electronics warm would be the least of your problems. Machines that do work get hot and processing data is work. I knew a guy in Pittsburgh who heated a 3500 square foothouse one winter with nothing but bitcoin miners. The heat generated from the microprocessors in those bitcoin generating computers was enough that he had to leave a few windows open to make the house livable. Excess heat kills engines and electronics alike so if it’s got vents, cooling fins or a fan make sure it gets cool air.

Last week I did a repair on an ECM that didn’t start after the owner used a big diesel powered forced air torpedo heater to heat up the oil pan of his Series 60. The last time I used one of those it was to thaw out a dynamometer cooling tower. Anyways, aDDEC dissipates heat though it’s aluminum case. In industrial and marine applications, a fuel cooled heatsink bolts up to the caseto help cooling. This DDEC IV had seen enough heat to cause the primary microprocessor to detach from the circuit board. The case had to be heated to at least 400 degrees Fahrenheit for that to happen. The connections between the microprocessor and the circuit board are made by a robot when the ECM is made. The contacts on the circuit board are closer together then the ridges on the edge of a quarter. This kind of damage isn’t considered repairable but some new micro solder tools had just come in and I wanted to test them out. I worked on that repair all night and when I looked up from the microscope it was morning again. I got it running a few hours later and now it’s back in service and has been running ever since. If you want to get a full life out of the parts inside the box, I suggest keeping the case temperature below 200 degrees Fahrenheit. On the cold side these DDECs should be fine to operate as low as -40 degrees Fahrenheit but that isn’t something, I have been able to test yet.

Written by Fernando DeMoura, Diesel Control Service. Phone 412-327-9400. Website: