Azbil JTD720A, User Manual, Page: 47 / 76

Azbil Corporation Starting and Stopping this Device
Model JTD720A - Smart Multivariable Transmitter 3-13
(2) Starting Operation
(i) Applying process pressure
In the following procedure, valves are operated to apply the differential pressure of the
process
to this device, and then the measurement value is checked using the communicator.
◆ Procedure ◆
(1) Check that the valves of the three-way manifold valve are in the following state.
(1) High pressure side stop valve: fully open
(2) Low pressure side stop valve: fully closed
(3) Equalizer valve: fully open
(2) Introduce process pressure into the low pressure side.
(1) Close the equalizer valve.
(2) Gradually open the low pressure side stop valve.
High Pressure Side Stop Valve
Three-Way Manifold Valve
Drain Plugs
Low Pressure Side
Stop Valve
High Pressure Side
Low Pressure Side
Pressure Equalizing Valve
(ii) Checking measured values
• Using the communicator, check the measured values.
• After checking , disconnect the communication cable, attach the device’s case cover,
and switch the process to normal operation.
• If the analog signal output, the displayed values, etc., do not match the process
conditions, recheck the setting range and the like. If this does not solve the problem,
carry out the troubleshooting
in Chapter 4, or contact us.
• If the measurement output and display do not stabilize, refer to Chapter 4 and adjust
the damping time constant.
Note: Transmitter responsiveness varies with each model. When replacing an instrument,
adjust the damping time constant as necessary so that it is appropriate for the
instrumentation loop.
(iii) Cautions following confirmation of readings
After checking the measured values, confirm that the device’s case cover is securely
closed. If it is not securely closed, rainwater and the like can enter the device and cause
damage to the terminals, electronics modules, etc., located inside.