FORM 150.72-NM1 (1020)
161
JOHNSON CONTROLS
8
TABLE 17 – 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 &
FAN STAGE 1 IS
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED
DIFFERENTIAL
PRESSURE &
FAN STAGE 1 IS
ENERGIZED
TB7-8 &
TB7-9
TB10-8 &
TB10-9
1-KF1 &
1-KF2
2-KF1 &
2-KF2
1-MF1 &
1-MF2
2-MF1 &
2-MF2
3
DP > PROGRAMMED
FAN CONTROL ON
PRESSURE AND FAN
STAGES 1 & 2 ARE
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
PRESSURE MINUS
PROGRAMMED
DIFFERENTIAL
PRESSURE & FAN
STAGES 1 & 2 ARE
ENERGIZED
TB7-8 &
TB7-9 &
TB7-10
TB10-8 &
TB10-9 &
TB10-10
1-KF1 &
1-KF2 &
1-KF3
2-KF1 &
2-KF2 &
2-KF3
3 FAN:
1-MF1 &
1-MF2 &
1-MF3
4 FAN:
1-MF1 &
1-MF2 &
1-MF3 &
1-MF4
3 FAN:
2-MF1
& 2-MF2
& 2-MF3
4 FAN:
2-MF1 &
2-MF2 &
2-MF3 &
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 seconds.
** 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) be-
tween turning fan stages on and o is
xed at 5 seconds.