0-100 mV signal consultation..

Hi,

Our client has a requirement, he needs to see & monitor the pressure level on suction & discharge side of a refrigerant compressor. This compressor unit outs 0-100 mV as per pressure level. I will be using plc for this application & signal amplifier to out 0-100mV to 0-5Vdc or any industrial signal.

I have not done anything like this before, so I may have overlooked something.

What are other things to consider with this type of application?

Wiring distance is one thing to consider. I would use a milliamp signal ( 4-20ma) to reduce noise problems. Shielded wiring.

Another is timing - speed of the converter, Clients required update rate, PLC Scan time etc

Is the signal is going to be used to close the loop in a control system?

Please give manufacturer of this compressor, (i am in this cooling business. I dont know anybody with output signal of only 100 mV.
IF so please use a converter to 4/20 mA it will even work when the input on the PLC is 0/10 volts.
if you give the type of plc and the card you are using you will receive an answer here very quick on the settings etc.
The converter should be close to the pressure sensor.

theripley said:

Hi,

Our client has a requirement, he needs to see & monitor the pressure level on suction & discharge side of a refrigerant compressor. This compressor unit outs 0-100 mV as per pressure level. I will be using plc for this application & signal amplifier to out 0-100mV to 0-5Vdc or any industrial signal.

I have not done anything like this before, so I may have overlooked something.

What are other things to consider with this type of application?

Click to expand...

I agree with the other posters...0 to 100 mV is an unusual range for process signals...BUT..it is NOT unusual for a DC shunt. Is there some DC motor involved here?

The refrigerant compressor is J&E hall. I agree that the 0-100mv signal is an unusual signal, I, too was doubting with it. But I saw the diagram & confirmed the output signal is 0-100mv.

Shooter,

I'm glad someone from cooling business joined this thread. Can you pls double check the signal on J&E hall compressor, I might be reading/ interpreting it wrongly. Thanks for the help in advance.

With regards to your prevoius post, i plan of using keyence PLC with this application. I will using a PID function for the control as the client requires stable MV overtime. This is in contrast with my previous post saying apllication is only monitoring.

I will be "watching" suction side pressure & control a valve via PID.

I hope my description is informative, otherwise please reply with your questions.

MichaelG said:

Is the signal is going to be used to close the loop in a control system?

Click to expand...

YES.

The signal will be used to PID control a hydraulic valve.

please send me the cool diagram and the type of compressor and of this sensor, i only find a Pt100 sensor (temperature) and yes this has 100 mV signal

The controller is Fridgewatch 2000 controller Mk4 (by J&E Hall). This controller can control Hallscrew 2000 series compressors, Hallscrew 2100 series compressors & Hallscrew 3100, 3200 & 4200 series compressors.