York YLUA0078 - CONDENSER FAN CONTROL - YLUA0078 - YLUA0095; TABLE 27 - YLUA0078 - YLUA0095 LOW AMBIENT CONDENSER FAN CONTROL - DISCHARGE PRESSURE CONTROL

JOHNSON CONTROLS
136
FORM 150.73-NM1
ISSUE DATE: 09/04/2020
SECTION 8 – UNIT OPERATION
CONDENSER FAN CONTROL - YLUA0078 – YLUA0095
TABLE 27 - YLUA0078 – YLUA0095 LOW AMBIENT CONDENSER FAN CONTROL –
DISCHARGE PRESSURE CONTROL
FAN
STAGE
ON OFF
CONTACTOR
I/O BOARD
OUTPUT
FAN #
SYS 1 SYS 2 SYS 1 SYS 2 SYS 1 SYS 2
1
1 FAN
REV
DP > Fan Ctrl On
Press
DP < Fan Ctrl On Press
– Di󰀨. Press.
7M 10M TB7-8 TB10-8 1 REV 2 REV
2
1 FAN
FWD
DP > Fan Ctrl On
Press
+ 20 psig
(1.38 Bars)
DP < Fan Ctrl On Press.) –
[Di󰀨 Press. + 20 psig
(1.38 Bars)]
8M 11M TB7-9 TB10-9 3 FWD 4 FWD
3
2 FANS
FWD
DP > Fan Ctrl On
Press
+ 40 psig
(2.76 Bars)
DP < Fan Ctrl On Press.) –
[Di󰀨 Press. + 40 psig
(2.76 Bars)]
8M
and
9M
11M
and
12M
TB7-9
and
TB7-10
TB10-9
and
TB10-10
1 and
3 FWD
2 and
4 FWD
When Low Ambient Control of the fans is
selected, fan control will be by discharge
pressure only.