There are a couple of reasons to pot things. One, is to protect proprietary information, and to prevent any attempted repair, another is to resist vibration damage, and a third is for atmospheric problems, like corrosion/mold. Usually this is done with conformal coating. These can generally be removed. If it is a programmable, and protected against readout, you are done. It seems much more likely to be a "power" part. Like mentioned before, these parts are susceptible to lightning, external shorts...
That said, I think it is extremely poor to abandon a product after ten years. Can you imagine if someone told you your 10 year old CNC was irreparable? They should give you a heck of a good discount on a new unit.
regards,
Jon P.
Given the environment that the things are installed into, I feel pretty sure that the reason for potting (which may actually be conformal coating) is to prevent damage from conductive dust, such as grinding dust, etc. Condensation is another issue of the same importance, since the PP may be installed in an area that is for all intents and purposes the same as being under a shed. It's quite sensible to do that.
It is reasonably common to "pot"or "conformal coat" the boards in HVAC equipment, for similar reasons.
"Potting" is generally understood to be putting the electronics into a 5 sided box, and filling it up above the electronic parts with some form of "goo". Soft, hard, epoxy, silicone, some are even a material that is semi-liquid, like very thick jell-o. That sort of material is usually used inside the modules in a VFD.
Conformal coating may be a similar material, (but not the Jell-O type) that is simply poured over the components on the PWB. May be again soft, hard, etc.
Neither is generally used as a heatsink compound, at least not other than for regular board-mounted components. For power devices, the heatsinking is through very thin layers of heatsink "grease", which may actually be a filled wax material. ANYTHING thicker has too much thermal resistance to be used as a primary heat path in a power application.
As for longevity and repairability, 10 years is not bad. The requirement has been in consumer goods that the item should be repairable for 5 years past the last sale, but that is widely ignored. Many companies will not do any repairs nor support repair companies with parts, for any units that are not under warranty.
For industrial equipment, I am not sure if there is any time requirement.
When the stock of parts is gone, it's gone. A small run of parts for repair purposes is likely to be expensive, if it is even possible to obtain the parts at the present time. The higher cost of s small run would cut into the potential for actual sales of them, folks would just replace, since by that time other things will be degraded as well.
And, as noted, the device may not be up to current standards, although most will be grandfathered, and for such items repairs are normally permitted.
Rotary converter?
Very effective in most cases. Not ALL cases..... Provides a "similar" output as the PP, but not balanced anywhere near as well, and with a definite lower output on the generated leg under load and even at idle without special load-dependent compensation..
if you can use it.... great. if not, then you want real 3 phase, and the PP provides output at least as good as native 3 phase.
