York YLAA0180 - Table 27 - YLAA STANDARD CONDENSER FAN CONTROL USING DISCHARGE PRESSURE ONLY (2, 3, OR 4 FANS PER SYSTEM)

JOHNSON CONTROLS
162
FORM 150.72-ICOM7
ISSUE DATE: 10/22/2020
SECTION 8 – UNIT OPERATION
TABLE 27 - YLAA STANDARD CONDENSER FAN CONTROL USING DISCHARGE PRESSURE ONLY (2, 3,
OR 4 FANS PER SYSTEM)
FAN
STAGE
ON* OFF**
IPUII I/O OUTPUT
FAN
CONTACTOR
FAN #
SYS 1 SYS 2 SYS 1 SYS 2 SYS 1 SYS 2
1
DP > PROGRAMMED
FAN CONTROL ON
PRESSURE
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED
DIFFERENTIAL
PRESSURE
7B7-8 TB10-8 1-KF1 2-KF1 1-MF1 2-MF2
2
DP > PROGRAMMED
FAN CONTROL ON
PRESSURE AND FAN
STAGE 1 IS
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED
DIFFERENTIAL
PRESSURE AND FAN
STAGE 1 IS
ENERGIZED
TB7-8
and
TB7-9
TB10-8
and
TB10-9
1-KF1
and
1-KF2
2-KF1
and
2-KF2
1-MF1
and
1-MF2
2-MF1
and
2-MF2
3
DP > PROGRAMMED
FAN CONTROL ON
PRESSURE AND FAN
STAGES 1 AND 2 ARE
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED
DIFFERENTIAL
PRESSURE AND FAN
STAGES 1 AND 2
ARE ENERGIZED
TB7-8
and
TB7-9
and
TB7-10
TB10-
8 and
TB10-9
and
TB10-10
1-KF1
and
1-KF2
and
1-KF3
2-KF1
and
2-KF2
and
2-KF3
3 FAN:
1-MF1
and
1-MF2
and
1-MF3
4 FAN:
1-MF1
and
1-MF2
and
1-MF3
and
1-MF4
3 FAN:
2-MF1
and
2-MF2
and
2-MF3
4 FAN:
2-MF1
and
2-MF2
and
2-MF3
and
2-MF4
* When a fan stage is turned on, the pressure for the next stage is increased 20 psig and ramped back to the programmed on pressure over
the next 20 s.
** When a fan stage is turned o󰀨 (Programmed ON pressure minus the di󰀨erential), the OFF pressure for the next stage is decreased 20 psig
and ramped back to the programmed OFF pressure minus the di󰀨erential.
The time delay (fan delay timer) between
turning fan stages on and o is xed at 5 s.