Watlow Electric Micro-Based Autotuning Control SERIES 980/985 - Manual (Page 39)

RTD Field Calibration Procedure
Equipment Required
l
1K ohm precision decade resistance box with 0.01 ohms resolution.
Setup And Calibration
NOTE
Before calibration on an installed control, make sure all data and
parameters are documented. See Setup and Operation Charts,
Pages 26 and 28.
1. Connect the AC line voltage L1 to Terminal #4, L2 to Terminal #7, and
Ground to Terminal #8. Jumper for correct line voltage. See Chapter 2.
NOTE:
2. Connect the decade resistance box to Terminal #12,13 and 14 on the
Not all parameters
terminal strip. Use regular 20 - 24 gauge wire of the same length and
will appear. They
are
dependent on
type. your unit type. Use
only the steps that
3. Apply power to the unit and allow it to warm up for 15 minutes. After apply to your unit.
warm-up put the unit in the CAL menu. See Figure 33 on Page 37.
Press the MODE key until the rL0 prompt is displayed.
IMPORTANT:
When the MANUAL LED is ON the unit is automatlcally calibrating. Your
sequence is VERY important. Always move to the next prompt before
changing the calibration equipment.
4. Press the AUTO/MAN key twice to enter the MANUAL mode. The unit is
calibrating when the MANUAL LED is ON.
5. At the rL0 prompt, set the decade resistance box to the correct low
setting- See the table below. Allow at least 10 seconds to stabilize.
Press the MODE key.
1 Calibration Low High
985A-2XX0-0X00
1° 17.31 317.33
985A-3XX0-0X00 0.1 ° 59.57 177.13
6. At the rHI prompt, set the decade resistance box to the correct high
setting. Allow at least 10 seconds to stabilize. Press the AUTO/MAN key
twice to exit the MANUAL mode. This pauses calibration to allow you to
exit the CAL mode.
Table 2-
RTD Settings.
Appendix WATLOW Series 980/985 User’s Manual 39