Table of Contents
Advertisement
FORM 150.72-ICOM6
ISSUE DATE: 08/03/2022
TABLE 25 - 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 ON
2
PRESSURE AND
FAN STAGE 1 IS
ENERGIZED
DP > PROGRAMMED
FAN CONTROL ON
3
PRESSURE AND FAN
STAGES 1 AND 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) between
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
TB7-8
PROGRAMMED
and
DIFFERENTIAL
TB7-9
PRESSURE AND
FAN STAGE 1 IS
ENERGIZED
DP < PROGRAMMED
FAN CONTROL ON
TB7-8
PRESSURE MINUS
and
PROGRAMMED
TB7-9
DIFFERENTIAL
and
PRESSURE AND FAN
TB7-10
STAGES 1 AND 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
and
and
and
TB10-9
1-KF2
2-KF2
TB10-
1-KF1
2-KF1
8 and
and
and
TB10-9
1-KF2
2-KF2
and
and
and
TB10-10
1-KF3
2-KF3
FAN #
SYS 1
SYS 2
1-MF1
2-MF2
1-MF1
2-MF1
and
and
1-MF2
2-MF2
3 FAN:
3 FAN:
1-MF1
2-MF1
and
and
1-MF2
2-MF2
and
and
1-MF3
2-MF3
4 FAN:
4 FAN:
1-MF1
2-MF1
and
and
1-MF2
2-MF2
and
and
1-MF3
2-MF3
and
and
1-MF4
2-MF4
8
181
Hide quick links:
Advertisement
Table of Contents
Troubleshooting
