York YLUA0248 Series, Installation Operation & Maintenance

Page: 115 / 158

JOHNSON CONTROLS
115
SECTION 7 – UNIT CONTROLS
FORM 150.73-NM2
ISSUE DATE: 09/07/2020
7
A single system condensing unit MUST
have a jumper between terminals 13 -
17 on terminal block XTBC1. If the
jumper is not installed, which is the
correct configuration for YLUA0248 &
0498 units, the unit will act as a 2-sys -
tem unit. The jumper is only checked
by the micro at unit power-up. If the
jumper needs to be removed, power
must be removed and re-applied to
register the change in memory.
N U M B E R O F F A N S
P E R S Y S T E M = X
The number of fans per system is programmed for the
total number of fans on each system, or the total number
on the condensing unit divided by 2.
This MUST be programmed correctly
to assure proper condensing unit op-
eration.
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 Current Feedback option, the trip
voltage for a specific system or unit high current trip
can be programmed. It also calibrates the current read-
out under the OPER DATA key. The approximate pro-
grammed value is calculated using the following for-
mulas:
460VAC System Trip Volts
For individual system high current trip programming
on 460VAC units:
• 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 pro-
grammed
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 calcula-
tion and programming will be necessary for the other
system in a 2-system unit.
460VAC Unit Trip Volts
For total unit high current trip programming on
460VAC units:
• Add the sum of all the compressor and fan RLA’s
in the unit
• Multiply the sum by 1.25
• Divide by 225A
• The resulting voltage is the value that should be pro-
grammed
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 Units
On 208/230VAC units, the process is similar, but in-
stead of performing the calculation using 225A, a num-
ber of 450A must be substituted.
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 units on a single RS-485
line. ID 0-7 is selectable.