Do you mean you want to mount the PLC controller, I/O modules, etc, in a vibrating environment that is also hot? Wow.
Unfortunately, I can help. All of my PLCs are usually mounted on a wall, cabinet in a non-vibrating and somewhat HVACed environment.
Just curious, what application is this?
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
PLC to be located in engine area of railroad locomotive, subject to ambient temps of up to 195F, while in standby mode. During operation, temp can range from -40F to 130F.
PLC mounted in a Nema 12 non-ventilated enclosure which is in turn mounted with vibration isolators. Shock load experienced during coupling is more of a concern than engine vibration. Enclosure can not be directly ventilated due to presence of coal dust in surrounding air. Sound like a challenge?
Are you seriously saying that there is no room to locate it outside out of the engine bay? I have trouble believing that there is not room for a PLC cubicle anywhere on something the size of a locomotive.
You're looking at a controller designed for the full military temperature range, and they just don't exist in the PLC world. You could probably get a custom controller built designed and built to what amounts to a military specification if you have the money to pay for it.
Low temperatures can be overcome by a space heater. High temperature you will need either Peltier coolers or an enclosure cooler with internal air circulation. Why are you so convinced that it must be installed in the engine bay? A cooler environment can't be more than 30' away on a locomotive, and any decent PLC will be able operate normally with transducers and actuators at ten times that distance. Put the electronics somewhere cooler and let the transducers and actuators deal with the hostile environment.
Dovo,
There are enclosure coolers as JLS that circulate internal air only.
What consequences will PLC failure result in, Surely not a Runaway Locomotive?
What type of I/O are you dealing with? Is there a chance you can move the PLC enclosure outside of the engine compartment into a regulated enviroment? Consider using multiport I/O blocks to carry signals to and from PLC location.
Coal fired locomotive? Is this a historical/museum (or retro villiage) piece/reproduction or is this regular service? Just curious. Absolutely nothing to deal with your dilema.
How big is your locomotive? And, what are the I/Os and where are they located?
Heating is fairly easy, as others have said, solved with a strip heater.
Cooling is tougher, since the chiller and system will be subject to the same problems as the PLC.
I don't know much about shock from the coupling of cars. But I guess if its a problem, its a problem.
Hmmm. Not much help here am I? Sorry.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
For cabinet cooling, use a Vortex cooler, the locomotive should have plenty of air, and these coolers work well in those kinds of environment.
For cabinet mounting, use the military style mounts with a coil of stainless steel wire between two metal brackets, these are rated for high G's and we have had good luck with them, we use McMaster Carr in the US for source.
Catserveng's mount suggestion is a good one. I have designed several systems for mounting and control in a rail car. It's a b*tch! The shock loads are truly impressive. Please note that a poorly managed slack train can generate major shocks. You should see what happens to the people subjected to this stuff. They are thrown thru shower doors onto toilets breaking arms. Or across a room from a top bunk to impact the far wall only 2 inches below the height they were sleeping at.
I believe any standard PLC will have problems with the shock loads. We've had oscillators ripped off the boards. You need mounts that spread the G-loads out over time.
I think you will be better served by a relatively small single board computer properly mounted with wide temp designed in. <Automotive>
In keeping with itsmoked suggestion of a single board computer, you might also look at the Telecom industry machines for "Bellcore Standards", specifically "Sismic 7".
It is now "Telecordia". More specifically "NEBS" compliance.
Bellcore implemented standards for earthquake surviablity/operation as part of their standard. The "shake and bake" standards for the shaking are a much shorter duration than continuous vibration, however the shock mounting and general robustness of the hardware is typically far more rugged than standard computing hardware.
On page 1320 of catalog #113 is the "Stainless Steel Wire Rope Mounts". Part numbers 62225K1 thru 62225K6 depending on size and load capacity you need.
For high shock load applications we use the mounts on two planes, usually we put a mount on the top and bottom vertically, and top back and bottom back, or right and left back, depending on the support structure. Have used these on military applications tested to 15 g's with good results.
they manufacture automation for rail vehicles. I don't know about in the US but in Europe I believe there other restrictions regarding automation on rail vehicles. One I belive is that you cannot use red LEDs for I/O status
Hope this helps
Blackcountryman
