Mitsubishi FR - S500 instruction manual Calibration example, 107, Start, End

(7) Calibration example

(A detector of 4mA at 0°C (32°F) and 20mA at 50°C (122°F) is used to adjust the room temperature to 25°C (77°F) under PID control. The set point is given to across inverter terminals 2-5 (0-5V).)

START

Convert the set point into %.

Calculate the ratio of the set point to the detector output.

Make calibration.

Set the set point.

Enter a voltage to across terminals 2-5 according to the set point (%).

Determine the set point.

Determine the set point of the item to be adjusted.

Operation

Set the proportional band and integral time to slightly higher values and the differential time to "- - -" (No control), and switch on the start signal.

.......Detector specifications

When the detector used has the specifications that 0° C is equivalent to 4mA and 50° C (122° F) to 20mA, the set point of 25° C (77° F) is 50% because 4mA is equivalent to 0% and 20mA to 100%.

.......When the set point setting input (0 to 5V) and

detector output (4 to 20mA) must be calibrated, make the following calibration*.

.......Set point = 50%

Since the specifications of terminal 2 are such that 0% is equivalent to 0V and 100% to 5V, enter 2.5V into terminal 2.

For PU operation, set the set point (0 to 100%) in Pr. 93.

.......Set the room temperature to 25° C (77° F)

Set "20" or "21" in Pr. 88 and turn on the X14 signal to enable PID control.

.......During operation, set the proportional band and

integral time to slightly higher values and set the differential time to "- - -" (No control). In accordance with the system operation, reduce the proportional band and integral time. For slow response system where a deadband exists, differential control shuold be turned on and increased slowly.

Is the process		Yes
value steady?
	No
				2
Adjust parameters.			Optimize parameters.
Set the proportional band and			While the process value is steady,
integral time to slightly higher values			the proportional band and integral
and set the differential time to a			time may be reduced and the
slightly lower value to stabilize the			differential time increased
process value.			throughout the operation.

END

*When calibration	Use Pr. 38 and calibration parameters C2 to C4 (terminal 2)
is required	and Pr. 39 and calibration parameters C5 to C7 (terminal 4) to
	calibrate the detector output and set point setting input.
	Make calibration in the PU mode when the inverter is at a stop.

107