Table 27 - Ylua0078 - Ylua0095 Low Ambient Condenser Fan Control - Discharge Pressure Control - York YLUA0078 Installation Operation & Maintenance

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