JOHNSON CONTROLS
121
SECTION 7 – UNIT CONTROLS
FORM 150.27-NM1
ISSUE DATE: 09/30/2015
7
Unit Trip Volts
For total chiller high current trip programming on
460VAC chillers:
•
Add the sum of all the compressor and fan RLA’s
in the chiller.
•
Multiply the sum by 1.25.
•
Divide by 225A.
•
The resulting voltage is the value that should be
programmed.
For example, if fan and compressor RLA’s total 180A:
5V x 180A x 1.25 = 1125VA
= 5.0V
225A 225A
The programmed value will be 5.0V.
R E M O T E U N I T I D
P R O G R A M M E D = X
When communications is required with a BAS or Op-
tiView Panel, individual unit IDs are necessary for
communications with specific chillers on a single RS-
485 line. ID 0-7 is selectable.
TABLE 15 -
PROGRAM KEY LIMITS AND DEFAULT
PROGRAM VALUE
MODE
LOW LIMIT
HIGH LIMIT
DEFAULT
Discharge Pressure Cutout
—
325 PSIG
575 PSIG
570 PSIG
22.4 BARG
39.6 BARG
39.3 BARG
Suction Pressure Cutout
Water Cooling
80.0 PSIG
120.0 PSIG
80.0 PSIG
5.52 BARG
8.27 BARG
5.52 BARG
Glycol Cooling
42.0 PSIG
70.0 PSIG
44.0 PSIG
2.9 BARG
4.83 BARG
3.03 BARG
Low Ambient Temp. Cutout
Standard Ambient
25.0 °F
60.0 °F
25.0 °F
-3.9 °C
15.6 °C
-3.9 °C
Low Ambient
(N/A)
0 °F
60.0 °F
25.0 °F
-17.8 °C
15.6 °C
-3.9 °C
Leaving Chilled Liquid
Temp. Cutout
Water Cooling
—
—
36 °F
2.2 °C
Glycol Cooling
-1.0 °F
36.0 °F
36.0 °F
-18.3 °C
2.2 °C
2.2 °C
Anti-Recycle Timer
—
300 SEC.
600 SEC.
600 SEC.
Fan Control On Pressure
(Not Applicable To A Ycrl)
—
N/A
N/A
N/A
N/A
N/A
N/A
Fan Differential Off Pressure
(Not Applicable To A Ycrl)
—
N/A
N/A
N/A
N/A
N/A
N/A
Total Number Of Compressors
Single System
2
3
3
Dual System
4
6
6
Number Of Fans Per System
N/A
N/A
N/A
Unit/System Trip Volts
Current Feedback
0.5 Volts
4.5 Volts
2.5 Volts
Remote Unit Id
—
0
7
0
