FES alarm issues

[CanadianIce]

Hi guys

I'm working on two FES packages using a Micro Master control model 575E with the larger display. Both micros were manufactured in 1989.

First package has an energised alarm output even though there isn't an alarm present. The module is working and the LED is on. I need to connect the existing system alarms to this output but cannot until this problem is sorted Customer says the package was used when they got it and this problem has always been there.

The other package is showing a Pre alarm 05 which the manual says is Low Process Temp, when the compressor is off. Then when the compressor starts it changes to a run alarm. This package is controlled with suction pressure and programming and dip switch settings appear to be correct. The process temp input isn't connected so it reads -459 but the micro shouldn't use this information while controlling on suction pressure. Other packages I've worked on were set up the same way with no ongoing alarms. This package was also used when it was installed and the problem has always been there.

My thoughts are, either I have misinterpreted the set up configuration, the eproms have wrong program for these micros or possibly a board problem. I don't believe there is a connection issue. Any thoughts or suggestions?

Thanks

C Ice

[sterl]

Low Process Temp is typically a "second level" alarm used on something like a chiller where the compressor is looking at an application condition to establish whether it should run or quit...If the loaded software has it the package was probably portion of that style of plant. The number should be addressable but likely the processor won't accept and entry lower than -459 so chances are you will end up with a ICTD on it for no good reason or a reload of the software....

FES used to have in the Data Sheets for every compressor the Register Addresses....The only way you can identify what that live output is trying to do.

But I suspect it is the High Liquid Level because the loop through your liquid level switches is supposed to be normally energized; and land on an Input Module. The associated register would then de-energize the output module...Does the machine's screen actually tell you anything in terms of what the alarm is? Often the Liquid Level is indicated as AUX 1 but that again is a guess.

Contact FES and see if they can send you the Data Sheets for each package as well as the pertinent operating instructions and addendums to them. They also may have the software for the PLC archived. If your site handle is close to your company name, I don't think it will be much of an issue....

[salamander]

I've had this problem before. It is a glich in the system. The process temp should not alarm in suction control, but is does sometimes. Just re-enter all the process parameters and it will clear up.