PCC-IV Instruction Manual (rev. 0.1)
Page 4-13
Section 4
–
Menu Operations
14. If there were no errors, press Escape to return to the menu; the new calibration will be in effect.
15. Repeat the above steps for any other Boards that are going to be calibrated.
16.
The user may “Save Config Changes” from the Memory submenu, if additional redundancy is
desired.
17.
Important!
Be sure to exit Service Manual from the Service Manual submenu.
Analog Output Calibration Procedure
WARNING
The PCC-IV is commonly used to control potentially dangerous Combustion and Chemical
Processes. VERIFY THAT THE PROCESS BEING CONTROLLED HAS BEEN SAFELY
SECURED, ISOLATED, OR BYPASSED (AS REQUIRED BY THE SITE CONDITIONS)
BEFORE CALIBRATING THE PCC-IV.
FAILURE TO DO SO CAN RESULT IN EQUIPMENT
DAMAGE, INJURY, OR DEATH.
This procedure requires a DC milliamp meter to measure the 4-20 mA output signal to /-0.002 mA. This
means that the DC milliamp meter must display at least “5 ½ digits” (i.e., 20.001). However, not all 5 ½ digit meters
have +/-0.002 mA accuracy, depending on the accuracy specification of the meter, a 6 ½ digit meter may be
required.
Most portable test meters and voltage calibrators have 4 ½ digits or less of display resolution. “Calibrating” the
PCC-IV with a less than 5 ½ digit DC milliamp meter will result in lower PCC-IV accuracy.
This procedure applies to the CPU Board (Board 0), Option Board 1, and Option Board 2.
1. Set All Outputs to SM, using the Service Manual submenu.
2. Remove all field wiring from the Analog Output channel to be calibrated. Alternatively, un-plug
the field wiring connector, and plug-in a spare field wiring connector.
3.
Wire the “+” terminal to the milliamp meter (see Section 2 for terminal numbers).
4.
Wire the “-” terminal to the milliamp meter.
5. Go to the Calibrate I/O submenu.
6. Select which Board is being calibrated (CPU Board = 0; Option Card 1 = 1; Option Card 2 = 2).
7. Select which Channel is being calibrated.
a. While a group of Analog Inputs are calibrated all at the same time, each 4-20 mA Output
must be calibrated individually.
8. Set Type to AOUT.
9. Press Enter.
a. The message
“SET OUTPUT TO 4.00 MILLIAMPS, THEN PRESS ENTER” will be
displayed.
b.
The error message “MUST BE IN S/M TO CALIBRATE” will be displayed if ALL the
Outputs are NOT in S/M mode (see above).
c.
The error message
“CALIBRATION ABORTED, DEVICE OUT OF COMPLIANCE” will
be displayed if the actual current output is not approximately 4 mA. This can be caused
by:
i. Milliamp loop is open circuit
ii. The test meter is set to Volts instead of Amps
iii. There is too much resistance in the loop
iv. An external voltage or current source is connected to the field wiring
d. If there was an error, press Escape to return to the menu; the original calibration will still
be in effect.
10. Using the INC or DEC key, and observing the milliamp meter, set the 4-20 mA Output to 4.000
mAdc, +/-0.003.
a. The Channel Value displayed on the PCC-IV front panel is a percentage of output. 0.000
= 0% = 4 mA.
b. As you press INC or DEC, this Channel Value should be ignored. Set the output to 4 mA
based on the attached milliamp meter.
11. Press Enter.
a. The message
“SET OUTPUT TO 20.00 MILLIAMPS, THEN PRESS ENTER” will be
displayed.
