Watlow Series 945 High/Low Limit Control - Manual (Page 17)

17
WATLOW Series 945 High/Low Limit User's Manual
0 - 5V/4-20mA Input
4-20mA Input Field Calibration Procedure
Equipment Required:
• Precision current source 0-20mA minimum range with 0.01 mA resolution.
Setup And Calibration
1. Connect the AC line voltage L1, L2, and ground to the proper terminals on the Series
945. Jumper for correct line voltage. See Chapter 2.
2. Connect the voltage/current source to Terminal #1 and #3. Jumper Terminal #2 to #3
on the Series 945 terminal strip. Use regular 20 - 24 gauge wire.
3. Apply power to the unit and allow it to warm up for 15 minutes. After warm-up put the
unit in the CAL menu. See Page 14. Press the MODE key until 4A is displayed.
4. Press the ALARM CLEAR key twice to enter the calibration mode. The unit is
calibrating when the ALARM CLEAR LED is ON. Make sure the LED is on only when
you are in the correct parameters. See Figure 16.
5. At the 4A parameter, set the mA source to 4.00mA. Allow at least 10 seconds to
stabilize. Press the MODE key.
6. At the 20A parameter, set the voltage/current source to 20.00mA. Allow at least 10
seconds to stabilize. The unit leaves the CAL mode if 1 minute passes between key
activations. Press ALARM CLEAR twice to exit the calibration mode. To conclude,
advance the MODE key to the next prompt or exit the CAL menu.
0 - 5 Volt Input Field Calibration Procedure
Equipment Required:
• Precision voltage source 0-5 volt minimum range with 0.001 volt resolution.
Setup And Calibration
1. Connect the AC line voltage L1, L2, and ground to the proper terminals on the 945.
2. Connect the voltage/current source to Terminal #1 and #3 on the Series 945 terminal
strip. Use regular 20 - 24 gauge wire.
3. Apply power to the unit and allow it to warm up for 15 minutes. After warm-up put the
unit in the CAL menu. See Page 14. Press the MODE key until OU is displayed.
4. Press ALARM CLEAR twice to enter the calibration mode. The unit is calibrating
when the ALARM CLEAR LED is ON. Make sure the LED is on only when you are in
the correct parameters. See Figure 16.
5. At the OU parameter, set the voltage/current source to 0.000volts. Allow at least 10
seconds to stabilize. Press the MODE key.
6. At the 5U parameter, set the voltage/current source to 5.000 volts. Allow at least 10
seconds to stabilize. The unit leaves the CAL mode if 1 minute passes between key
activations. Press ALARM CLEAR twice to exit the calibration mode. To conclude the
0-5 Volt calibration, advance the MODE key to the next prompt or exit the CAL menu.
IMPORTANT:
When the ALARM
CLEAR LED is ON
the unit is
automatically
calibrating. Your
sequence is VERY
important. Always
move to the next
prompt before
changing the
calibration
equipment.
NOTE
Before calibration
on an installed
control, make sure
all data and para-
meters are
documented. See
Setup and Operation
Tables, Pages 12
and 13.