Figure 21. External Reset (English); Figure 22. External Reset (Si) - McQuay MicroTech II Operation Manual

Figure 21. External Reset (English)

Figure 22. External Reset (SI)

For example, if the settings of Figure 21 and Figure 22 are used, the following occurs when External reset is selected:
External Analog Signal
4 mA
12 mA
20 mA
You can monitor the current value of the External Chilled Water Reset Signal on the Misc screen of the user interface.
Note that in all cases the displayed value is a conditioned value of 0–10 Vdc.
To set up External reset
1. Set the Chilled Water Temperature Reset Type variable to "External."
2. Set the following variables as required:
• Minimum System Setpoint
• Maximum System Setpoint
OM 780-2
54
Max System Spt= 54°F
49
44
Min System Spt= 44°F
40
0 2 4
0–10 Vdc:
0–20 mA: 0 4 8
External Signal
12
11
Max System Spt= 12°C
10
9
8
7
6
Min System Spt= 7°C
5
0 2 4
0–10 Vdc:
0 4 8
0–20 mA:
External Signal
Corresponding System Setpoint
44.0°F (7.0°C)
49.0°F (9.5°C)
54.0°F (12.0°C)
6 8 10
12 16 20
a0150
6 8 10
12 16 20
a0151
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