JOHNSON CONTROLS
93
FORM 150.62-NM6 (103)
The TOTAL NUMBER OF COMPRESSORS is the total
quantity of compressors in the chiller, and determines
the stages of cooling available. Note in Table 21, the
chiller may have single or dual systems.
This MUST be programmed correctly
to assure proper chiller operation.
A single system chiller MUST have a
jumper between terminals 13 - 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.
The number of fans per system is programmed for the
total number of fans on each system, or the total number
on the chiller divided by 2. This is only programmable on
YCAL0090 - YCAL0124 chillers.
This MUST be programmed correctly
to assure proper chiller operation.
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
2
N U M B E R O F F A N S
P E R S Y S T E M = X
460VAC SYSTEM TRIP VOLTS
For individual system high current trip programming on
460VAC 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.
460VAC UNIT TRIP VOLTS
For total chiller high current trip programming on 460VAC
chillers:
• Add the sum of all the 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.
208/230VAC CHILLERS
On 208/230VAC chillers, the process is similar, but
instead of performing the calculation using 225A, a
number of 450A must be substituted.
When communications is required with a BAS or Op-
tiView Panel, individual unit IDs are necessary for com-
munications with specic chillers on a single RS-485
line. ID 0-7 is selectable.
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
Depending on the option, the trip voltage for a
specic system or unit high current trip (See page
86) can be programmed. It also calibrates the current
readout under the OPER DATA key. The approximate
programmed value is calculated using the following
formulas:
R E M O T E U N I T I D
P R O G R A M M E D = X