Startup For 4194Hb And Hc Controllers - Emerson Fisher 4194HA Instruction Manual

4194HA, HB, HC Controllers
July 2018
When performing the checks, open loop conditions must exist. An open loop exists when the controller output does
not affect the input pressure or other control signal to the controller.
Note
If the controller has the auto/manual option (suffix letter E), be sure the controller is in the automatic mode before performing
prestartup checks. If the controller has the external feedback option, connect the controller output connection to the external
feedback connection (figure 2‐2). Disconnect after completing the prestartup checks.
1. Provide a means of measuring the controller output pressure by connecting the controller output to a pressure
gauge. Connect supply pressure to the supply pressure regulator and be sure it is delivering the proper supply
pressure to the controller. Do not exceed the normal operating pressure in table 1‐4.
2. For a controller with remote set point (suffix letter M), connect regulated pressure of 0.2 to 1.0 bar or 0.4 to 2.1 bar
(3 to 15 psig or 6 to 30 psig) to the remote set point connection at the top of the controller case.
3. Remove the two machine screws (key 6) and lift off the proportional band indicator cover (key 36).
4. Adjust the set point a minimum of 20 percent of input span above the process indicator.
5. Turn the reset adjustment to 0.01 minutes per repeat.
6. Turn the rate adjustment to OFF.
7. Adjust the proportional band knob to 5 percent DIRECT (direct action).
8. If necessary, connect a pressure source to the differential pressure unit and adjust the process indicator to the last
scale mark on the left side of the scale. If the last scale mark is 0 psig, a pressure source is not required.
9. The controller output pressure should be 0 psig.
10. Rotate the proportional band to 5 percent REVERSE (reverse action).
11. The controller output should be within 0.14 bar (2 psig) of the supply pressure.
12. If the controller output is within tolerance, adjust the proportional band adjustment to 400 percent in the desired
action, secure the proportional band indicator cover (key 36) with the two machine screws (key 6), and go to the
startup procedure. If the controller output pressure is not within tolerance, go to the calibration procedure for
4194HB and HC controllers for recalibration.

Startup for 4194HB and HC Controllers

Calibrate the controller prior to this procedure.
Note
When performing the startup procedure, keep in mind the initial settings are guidelines. They will vary depending on the actual
process being controlled.
1. Be sure the supply pressure regulator is delivering the proper supply pressure to the controller.
2. Move the set point adjustment to the desired set point.
3. Set the reset adjustment to 0.05 minutes per repeat for fast processes. Set it to 0.5 minutes per repeat for slow
processes. For controllers with rate, set the rate adjustment to OFF.
4. Set the proportional band adjustment to 100 percent for fast processes. For slow processes, calculate the
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Instruction Manual
D200156X012