Sitrans CU02 Alarm Unit with AS 100 Sensor

Damping is provided to slow the response of the display when rapid or minor fluctuations in the process or machinery operation are encountered. The greater the damping value (P86), the slower the response. (page 11 CU02 manual)

P-86 damping, display (1ƒ to 999), where ƒ = factory setting (page 18)

Thanks for the reply.

I will try today adjusting P-86 but from what I can remember this only seems to adjusts the display and not the relay/alarm. Do you know if adjusting P-86 will give damping to the relay/alarm?

I don't know and the manual doesn't say, like most manuals no longer provide a theory of operation.

So I strongly suspect, that like most instrumentation, the value in the display is the same value that is used for the decision for relay operation.

There are two independent damping factors, one for the display, the other for the retransmitting analog output. I would assume that the damping factor for the display affects the local relay operation.

Thanks for reply

Had ago today at adjusting P-86 from 2 to 15 this had the effect of damping the display and giving a more stable reading. It seems that the 'alarm' flag is still going as fast as it was. From my tests adjusting P-86 is only damping the display

Take a look at this graph

Feeder Speed at 5 RPM the majority of the readings are at 50% with the odd spike going below the alarm setting of 40%.

Feeder now set at 3 RPM the majority of readings are at 25% with the spikes going above the 40% thus resetting the 'alarm' flag. These spikes are the ones that are causing us problems and not bring up the Coal Flow Failure Alarm.

Now looking at the 4 to 20 mA's output and have adjusted P-85 to 25. At this value the output looks stable, but still moving 0.1 to 0.2 mA's.

I am thinking of connecting a PR Electronics Trip Amp to this output and using that to bring the Coal Flow Failure Alarm. Seem a waste not to use the CU02 relay

Is the graph a recording of the 4-20mA output? If so, what damping factor was applied during the recording?

Thanks for reply

Quote "Is the graph a recording of the 4-20mA output?" =

The graph is the display reading in % values with P-86 (Display Damping) set at 2. At this setting the readings are bouncing about from 15% to 45%.

I have then adjusted P-86 to 15 and P-13 (Relay 1 delay) to 3 this then brings the display reading between 25 to 30 and a more stable readable value. The 'alarm' flag still comes up so resetting the alarm but the majority of the readings are below the 40% alarm setting. This should be bring up the Coal Flow Failure Alarm but with the spikes the 'alarm' is reset.

The Damping factor for 4 to 20 mA's on P-85 (mA's Damping) set to 25. At this value the output looks stable, but still moving 0.1 to 0.2 mA's

I now have the Trip Amp will install on the current output ... hopefully tomorrow

I have today connected a Trip Amp to the CU02 output and using that to bring the Coal Flow Failure Alarm.

Its early days but so far looks promising

It just seems a waste not to use the CU02 relay

Thanks for your help