Quantech QTC3040T, Installation Operation & Maintenance

Page: 165 / 190

165
QUANTECH
FORM QTC3-NM1
ISSUE DATE 08/03/2022
SECTION 8 – UNIT OPERATION
8
TABLE 25 - QTC3 STANDARD CONDENSER FAN CONTROL USING DISCHARGE PRESSURE ONLY (5 OR 6
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 > PRO-
GRAMMED FAN
CONTROL ON
PRESSURE
DP < PRO-
GRAMMED
FAN CONTROL
ON PRESSURE
MINUS PRO-
GRAMMED
DIFFERENTIAL
PRESSURE
TB7-8 TB10-8 1-KF1 2-KF1 1-MF1 2-MF1
2
DP > PRO-
GRAMMED FAN
CONTROL ON
PRESSURE AND
FAN STAGE 1 IS
ENERGIZED
DP < PRO-
GRAMMED
FAN CONTROL
ON PRESSURE
MINUS PRO-
GRAMMED
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
and
1-MF3
2-MF1
and
2-MF2
and
2-MF3
3
DP > PRO-
GRAMMED FAN
CONTROL ON
PRESSURE AND
FAN STAGES 1
AND 2 ARE EN-
ERGIZED
DP < PRO-
GRAMMED
FAN CONTROL
ON PRESSURE
MINUS PRO-
GRAMMED
DIFFERENTIAL
PRESSURE
AND FAN
STAGES 1 AND
2 ARE ENER-
GIZED
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
5 FAN:
1-MF1
and
1-MF2
and
1-MF3
and
1-MF4
and
1-MF5
6 FAN:
1-MF1
and
1-MF2
and
1-MF3
and
1-MF4
and
1-MF5
and
1-MF6
5 FAN:
1-MF1
and
1-MF2
and
1-MF3
and
1-MF4
and
1-MF5
6 FAN:
1-MF1
and
1-MF2
and
1-MF3
and
1-MF4
and
1-MF5
and
1-MF6
NOTES:
* 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 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 s.