Low Ambient Condenser Fan Control - Ambient; Low Ambient Condenser Fan Control - Discharge; Pressure Control - York MILLENNIUM YCAL0043SC Manual

LOW AMBIENT CONDENSER FAN CONTROL
For unit operation below 25°F (-3.9°C) a low ambient kit
is required. The kit consists of a discharge pressure
transducer(s) and reversing contactors.
With the low ambient kit installed and the unit programmed
for low ambient operation, the condenser fans will oper-
ate as shown in Tables 38 and 39.
TABLE 38 – LOW AMBIENT CONDENSER FAN CONTROL – AMBIENT TEMPERATURE AND DISCHARGE

PRESSURE CONTROL

FAN STAGE
1 - 1 FAN REV
2 - 1 FAN FWD
DP > ctrl_press + 20 PSIG (1.38 Bars)
3 - 2 FANS FWD
DP > ctrl_press + 40 PSIG (2.76 Bars)
TABLE 39 – LOW AMBIENT CONDENSER FAN CONTROL – DISCHARGE PRESSURE CONTROL
FAN STAGE
1 - 1 FAN REV
2 - 1 FAN FWD DP > ctrl_press + 20 PSIG (1.38 Bars)
3 - 2 FANS FWD DP > ctrl_press + 40 PSIG (2.76 Bars)
YORK INTERNATIONAL
Again, notice that condenser fan operation can be pro-
grammed for either "temperature and discharge pressure
control," or "discharge pressure control only" as described
under Condenser Fan Control.
The fan control on-pressure (ctrl_press) and the fan
differencial off-pressure (diff_press) are programmable
under the PROGRAM key.
ON
OAT>25° F (-3.9°C)
OR
DP > ctrl_press
OAT>45°F (7.2°C)
OR
OAT > 65°F (18.3°C)
OR
ON
DP > ctrl_press
OFF
OAT < 20° F (-6.7°C)
AND
DP < ctrl_press - diff_press
OAT < 40°F (-4.40°C)
AND
DP < ctrl_press - diff_press + 20 PSIG (1.38 Bars)
OAT < 60°F (15.6°C)
AND
DP < ctrl_press - diff_press + 40 PSIG (2.76 Bars)
OFF
DP < ctrl_press - diff_press
DP < ctrl_press - diff_press + 20 PSIG (1.38 Bars)
DP < ctrl_press - diff_press + 40 PSIG (2.76 Bars)
FORM 150.62-NM2
2
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