Watlow Series 945, 1/4 DIN Microprocessor-BasedAuto-tuning Control - Manual (Page 37)

Appendix 37
WATLOW Series 945 User's Manual
IMPORTANT:
When the MANUAL
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 18
and 20.
0 - 5 or 0-10 Volt Output Field Calibration Procedure
Equipment Needed: • 20K
Ω
, 1/4 watt, 10% resistor • 4 1/2 digit digital multimeter.
Setup and Calibration
1. Connect the AC line voltage L1, L2, and ground to the proper terminals.
2. Connect the multimeter across the 20K
Ω
resistor to Terminal #17 (+) and #16 (-) for 0-
5Volt and 0-10Volt units on the Series 945 terminal strip. Use regular 20-24 gauge wire.
3. Apply power and allow warm up for 15 minutes. After warm-up put the unit in the CAL
menu. See Page 32. Press the MODE key until O1LO is displayed.
4. Press AUTO/MAN twice to enter the MANUAL mode. The unit is calibrating when the
MANUAL LED is ON. Make sure the unit is in the MANUAL mode only when you are in
the correct parameters. See Figure 41.
5. At the O1LO parameter, the multimeter should read approximately 0V. Allow at least 10
seconds to stabilize.
6. Use the UP/DOWN keys (reverse acting) to adjust the reading on the multimeter for
0.00V
±
0.05V. To achieve this, you will need to press and hold the UP or DOWN key
until the reading on the multimeter comes above 0V, then with the opposite key, adjust
the multimeter for 0.00V
±
0.05V.
7. At O1HI, the multimeter should read approx. 5V. Allow 10 seconds to stabilize. The unit
leaves the CAL mode if 1 minute passes between key activations.
8. Use the UP/DOWN keys (reverse acting) to adjust the reading on the multimeter for
5.00V
±
0.05V for 0-5Volt units and 10.00V
±
0.05V for 0-10Volt units.
9. Press the AUTO/MAN key twice to exit the MANUAL mode. To conclude, advance the
MODE key to the next prompt or exit the CAL menu.
0-20 or 4-20mA Output Field Calibration Procedure
Equipment Required: • 470
Ω
, 1/2 watt 10% resistor. • 4 1/2 digit digital multimeter.
Setup and Calibration
1.
Connect the AC line voltage L1, L2, and ground to the proper terminals.
2. Connect the multimeter in series with the 470
Ω
resistor to Terminals #17 (+)
and #16 (-) for 0-20mA units and 4-20mA units on the 945 terminal strip. Use
regular 20 - 24 gauge wire.
3. Apply power to the unit and allow warm up for 15 minutes. After warm-up put the unit
in the CAL menu. See Page 32. Press MODE until O1LO is displayed.
4. Press the AUTO/MAN key twice to enter the MANUAL mode. The unit is calibrating
when the MANUAL LED is ON. Make sure the unit is in the MANUAL mode only when
you are in the correct parameters. See Figure 41.
5. At the O1LO parameter, the multimeter should read approximately 0mA for 0-20mA
units, and 4mA for 4-20mA units. Allow at least 10 seconds to stabilize.
6. Use the UP/DOWN keys (reverse acting) to adjust the reading on the multimeter for
0mA
±
0.10mA on 0-20mA units, and 3.85mA
±
0.10mA on 4-20mA units. Press the
MODE key.
7. At O1HI, the multimeter should read approx. 20mA. Allow 10 seconds to stabilize. The
unit leaves the CAL mode if 1 minute passes between key activations.
8. Use the UP/DOWN keys (reverse acting) to adjust the reading on the multimeter for
20.15mA
±
0.10mA on 0-20mA units and 4-20mA units.
9. Press the AUTO/MAN key twice to exit the MANUAL mode. To conclude, advance the
MODE key to the next prompt or exit the CAL menu.
0-5 or 0-10 Volt/0-20 or 4-20mA Output