Table 17 - Ylaa Standard Condenser Fan Control Using Discharge Pressure; Only (2, 3, Or 4 Fans Per System) - York YLAA0285SE Manual

FORM 150.72-NM3 (1020)
ISSUE DATE 10/05/2020
TABLE 17 – YLAA STANDARD CONDENSER FAN CONTROL USING DISCHARGE PRESSURE ONLY
(2, 3, OR 4 FANS PER SYSTEM)
FAN
ON*
STAGE
DP > PROGRAMMED
1 FAN CONTROL ON
PRESSURE
DP > PROGRAMMED
FAN CONTROL
2
ON PRESSURE &
FAN STAGE 1 IS
ENERGIZED
DP > PROGRAMMED
FAN CONTROL ON
3
PRESSURE AND FAN
STAGES 1 & 2 ARE
ENERGIZED
* 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 seconds.
** When a fan stage is turned off (Programmed ON pressure minus the differential), the OFF pressure for the next
stage is decreased 20 PSIG and ramped back to the programmed OFF pressure minus the differential.
The time delay (fan delay timer) be-
tween turning fan stages on and off is
fixed at 5 seconds.
JOHNSON CONTROLS
IPUII I/O OUTPUT
OFF**
SYS 1
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
7B7-8
PROGRAMMED
DIFFERENTIAL
PRESSURE
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED TB7-8 &
DIFFERENTIAL TB7-9
PRESSURE &
FAN STAGE 1 IS
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
TB7-8 &
PROGRAMMED
TB7-9 &
DIFFERENTIAL
TB7-10
PRESSURE & FAN
STAGES 1 & 2 ARE
ENERGIZED
SECTION 8 – UNIT OPERATION
FAN
CONTACTOR
SYS 2 SYS 1 SYS 2
TB10-8 1-KF1 2-KF1
TB10-8 & 1-KF1 & 2-KF1 &
TB10-9 1-KF2 2-KF2
TB10-8 & 1-KF1 & 2-KF1 &
TB10-9 & 1-KF2 & 2-KF2 &
TB10-10 1-KF3 2-KF3
FAN #
SYS 1 SYS 2
1-MF1 2-MF2
1-MF1 & 2-MF1 &
1-MF2 2-MF2
3 FAN: 3 FAN:
1-MF1 & 2-MF1
1-MF2 & & 2-MF2
1-MF3 & 2-MF3
4 FAN: 4 FAN:
1-MF1 & 2-MF1 &
1-MF2 & 2-MF2 &
1-MF3 & 2-MF3 &
1-MF4 2-MF4
8
173