Compu-purge on IngersollRand Air Dryer

At my site, we have IngersollRand Air Dryer model HRD350 Heatless. As control system, this package used micro controller as Deltech Compu-purge. The control system is controlling the logic for 2 sets purge valves, change-over of desiccant tower and interlock system with the input as pressure transducer, temperature transducer, dew point and pressure switches.

Since installed in 1999 until now, we have a repetitive problem as controller suddenly "hang" without the abnormal alarm and after be reset by manual push-button on control card, control became normal anymore. But, on my site, abnormality of Air dryer will effect to ESD-2 because give impact to all instrument air. Until now, I still wait an analysis from local vendor, but I am sure the problem might be from EEPROM. However I cannot check actual logic in EEPROM since there is no EEPROM reader at my site and local vendor also still cannot show me a logic program inside EEPROM.

If you have a similar experience related this product package, please share with me. Thank you.

A: I work with PLCs and know that all it takes is a certain input condition and a program bit in the right place. more then likely that condition was not tried during testing, that is occuring now. Try and Make The manufacture aware of this! stay vigilant on them.

I have similar problems with my dryers. For no apparent reason it will go into standby mode and my dewpoint will go high. We have HRD475 model, it is supposed to use 5% or 10% purge air depending on dryer load, sometimes it uses 5% on one tower but never on the other. I've had a hard time finding someone with manufacturer that can tell me anything.

I have an IR HRD15-C dryer with Compu Purge. On the processor board there are two DIP switches that can be turned "on" to initiate the fixed cycle mode. This should get your dew point down.

Which dip switch(es) do you adjust? FYI...my deltech control card is deltech part 7DE88HE