159
JOHNSON CONTROLS
FORM 150.72-NM3 (1020)
ISSUE DATE 10/05/2020
SECTION 7 – UNIT CONTROLS
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
TABLE 11 – PROGRAM KEY LIMITS AND DEFAULT
* The minimum discharge pressure allowed is 235 PSIG. The Fan Dierential O Pressure High Limit will be lowered (reduced) to
prevent going below 235 PSIG based on where the fan control On Pressure is programmed.
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
0 °F 60.0 °F
25.0 °F
-17.8 °C 15.6 °C
-3.9 °C
LEAVING CHILLED LIQUID
WATER COOLING
—
—
36 °F
2.2 °C
TEMP. CUTOUT
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
—
360 PSIG 485 PSIG 385 PSIG
24.8 BARG 33.4 BARG 26.5 BARG
FAN DIFFERENTIAL OFF PRESSURE —
80 PSID 160 PSID* 125 PSID
5.51 BARD 11.03 BARD* 8.62 BARD
TOTAL NUMBER OF COMPRESSORS
SINGLE SYSTEM 2 3 3
DUAL SYSTEM 4 6 6
NUMBER OF FANS PER SYSTEM
2 4 3
UNIT/SYSTEM TRIP VOLTS CURRENT FEEDBACK 0.5 Volts 4.5 Volts 2.5 Volts
REMOTE UNIT ID — 0 7 0
When communications is required with a BAS or
OptiView Panel, individual unit IDs are necessary for
communications with specic chillers on a single RS-
485 line. Remote Unit ID 0-7 are selectable.