Quantech QTC3040T

Quantech
178
Form QTC3-NM1
Issue date: 12/19/2023
Section 8: Unit operation
The time delay (fan delay timer) between
turning fan stages on and o is xed at
5 seconds.
Table 25: QTC3 Standard Condenser Fan Control Using Discharge Pressure Only (5 or 6 Fans per System)
FAN
STAGE
ON* OFF**
IPU 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
TB7-8 TB10-8 1-KF1 2-KF1 1-MF1 2-MF1
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
and
1-MF3
2-MF1
and
2-MF2
and
2-MF3
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
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
* 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.