York YCAL0080SC Manuale Utente

YORK INTERNATIONAL

FORM 150.62-NM1

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 pro-
grammed for low ambient operation, the condenser fans
will operate as shown in Tables 41 and 42.

TABLE 41 –

LOW AMBIENT CONDENSER FAN CONTROL – AMBIENT TEMPERATURE AND DISCHARGE

PRESSURE CONTROL

Again, notice that condenser fan operation can be pro-
grammed for either “temperature and discharge pres-
sure control,” or “discharge pressure control only” as
described under Condenser Fan Control.

The fan control on-pressure (ctrl_press) and the fan def-
erential off-pressure (diff_press) are programmable un-
der the PROGRAM key.

TABLE 42 – LOW AMBIENT CONDENSER FAN CONTROL –  DISCHARGE PRESSURE CONTROL

OAT >25° F (-3.9°C)

OAT < 20° F (-6.7°C)

OR

AND

DP > ctrl_press

DP < ctrl_press - diff_press

OAT >45°F  (7.2°C)

OAT < 40°F (-4.40°C)

OR

AND

DP > ctrl_press  + 20 PSIG  (1.38 Bars)

DP < ctrl_press  - diff_press + 20 PSIG  (1.38 Bars)

OAT > 65°F (18.3°C)

OAT < 60°F (15.6°C)

OR

AND

DP > ctrl_press + 40 PSIG (2.76 Bars)

DP < ctrl_press - diff_press + 40 PSIG (2.76 Bars)

DP > ctrl_press

DP < ctrl_press - diff_press

DP > ctrl_press  + 20 PSIG  (1.38 Bars)

 DP < ctrl_press  - diff_press + 20 PSIG  (1.38 Bars)

DP > ctrl_press + 40 PSIG (2.76 Bars)

DP < ctrl_press - diff_press + 40 PSIG (2.76 Bars)