JOHNSON CONTROLS
148
FORM 150.67-NM2 (209)
Unit Controls
This MUST be programmed correctly
to assure proper chiller operation.
The Number of Fans Per System must be pro-
grammed as needed to match the number of fans
on each system.
Depending on the option, the trip voltage for a
specific system or unit high current trip can be
programmed. It also calibrates the current readout
under the OPER DATA key. The approximate
programmed value is calculated using the following
formulas:
System Trip Volts
For individual system high current trip programming
on chillers:
• Add the sum of the compressor and fan RLA’s
in the system
• 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 100A:
5V x 100A
x 1.25 =
625VA
= 2.8V
225A 225A
The programmed value will be 2.8V. A similar
calculation and programming will be necessary for the
other system in a 2-system chiller.
The Fan Differential Off Pressure is the programmed
differential pressure value that is used to stage the
condenser fans off, in relation to discharge pressure. Refer
to Condenser Fan Control in the UNIT OPERATION
section and Tables 19, 20, 21 and 22.
The TOTAL NUMBER OF COMPRESSORS is the total
quantity of compressors in the chiller, and determines
the stages of cooling available. Note in Table 13, the
chiller may have single or dual systems. Single system
units can have 2 or 3 compressors, while dual system
units may have 4 or 6 compressors.
This MUST be programmed correctly
to assure proper chiller operation.
A single system chiller MUST have a
jumper between terminals J9-7 and
+24V on the I/O board. This connec-
tion can be made between terminals
13 and 17 on terminal block CTB1. If
the jumper is not installed, the unit will
act as a 2-system chiller. The jumper
is only checked by the micro at unit
power-up. If the jumper is removed,
power must be removed and re-applied
to register the change in memory.
T O T A L N U M B E R O F
C O M P R E S S O R S = 6
N
U
M
B
E
R
O
F F
A
N
S
P E
R S
Y
S
T
E
M =
X
F A N D I F F E R E N T I A L O F F
P R E S S U R E
= X X X P S I G
S Y S X T R I P V O L T S
= X . X V O L T S
U N I T T R I P V O L T S
= X . X V O L T S
Summary of Contents for YCAL0019
Page 55: ...FORM 150 67 NM2 209 55 JOHNSON CONTROLS 5 5 ELEMENTARY WIRING DIAGRAM CON T LD12699D...
Page 57: ...FORM 150 67 NM2 209 57 JOHNSON CONTROLS 5 5 ELEMENTARY WIRING DIAGRAM CON T LD12693C...
Page 59: ...FORM 150 67 NM2 209 59 JOHNSON CONTROLS 5 5 ELEMENTARY WIRING DIAGRAM CON T LD 12198...
Page 61: ...FORM 150 67 NM2 209 61 JOHNSON CONTROLS 5 5 LD12702 ELEMENTARY WIRING DIAGRAM CON T...
Page 63: ...FORM 150 67 NM2 209 63 JOHNSON CONTROLS 5 5 LD12696 ELEMENTARY WIRING DIAGRAM CON T...
Page 65: ...FORM 150 67 NM2 209 65 JOHNSON CONTROLS 5 5 CONNECTION WIRING DIAGRAM CON T LD12703B...
Page 67: ...FORM 150 67 NM2 209 67 JOHNSON CONTROLS 5 5 CONNECTION WIRING DIAGRAM CON T LD12697B...
