Quantech QCC2015CEE, Installation, Operation And Maintenance Manual, Page: 137 / 172

QUANTECH
137
SECTION 8 – UNIT OPERATION
Form QCC2-NM1
Issue Date: 5/20/2021
8
Figure 40 - QCC2040C – QCC2070C Fan Location (Typical)
Fan #1
Fan #2
Fan #3
Fan #4
LD07403A
Table 18 - QCC2015C – QCC2070C Condenser Fan Control Using Outdoor Ambient Temperature and Discharge
Pressure (Discharge Pressure Controls Will Not Function Unless the Optional Discharge Pressure Transducer is
Installed)
FAN
STAGE
ON OFF
CONTACTOR
I/O BOARD
OUTPUT
FAN #
SYS 1 SYS 2 SYS 1 SYS 2 SYS 1 SYS 2
1
1 FAN
FWD
OAT >25°F (-3.9°C)
or
DP > Fan Ctrl On Press
OAT < 20°F (-6.7°C)
and
DP < Fan Ctrl On Press –
(Diff. Press.)
8M 11M TB7-9 TB10-9 3 4
*3
2 FANS
FWD
OAT >65°F (18.3°C)
or
DP > Fan Ctrl On Press
+ 40 psig (2.76 Bars)
OAT < 60°F (15.6°C)
and
DP < Fan Ctrl On Press.-
[Diff. Press + 40 psig
(2.76 Bars)]
7M &
8M
10M &
11M
TB7-8
&
TB7-9
TB10-8
&
TB10-9
1 & 3 2 & 4
Table 19 - QCC2040C – QCC2070C Condenser Fan Control Using Discharge Pressure Only
FAN
STAGE
ON OFF
CONTACTOR
I/O BOARD
OUTPUT
FAN #
SYS 1 SYS 2 SYS 1 SYS 2 SYS 1 SYS 2
1
1 FAN
FWD
DP > Fan Ctrl On
Press
DP < Fan Ctrl On Press –
(Diff. Press.)
8M 11M TB7-9 TB10-9 3 4
*3
2 FANS
FWD
DP > Fan Ctrl On
Press
+ 40 psig (2.76 Bars)
DP < Fan Ctrl On Press.) –
[(Diff Press.) + 40 psig (2.76 Bars)]
7M &
8M
10M
& 11M
TB7-8
&
TB7-9
TB10-8
&
TB10-9
1 & 3 2 & 4
* NOTE: STEP 2 is not active in the “Standard Ambient” mode. When changing to “Low Ambient” control, fan power wiring also changes.