Carrier Transicold 69NT40-561-001, Руководство по эксплуатации и обслуживанию

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4–9 T-340
c. The safety heater termination thermostat (HTT) is attached to an evaporator coil circuit and will open the
heating circuit if overheating occurs.
Figure 4.7 Perishable Mode Heating
NOTE
The EEV and DUV are independently operated by the microprocessor. For full diagrams and legend, see
Section 8 .
4.3.13 Perishable Mode - Trim Heat
If the system capacity has been decreased to the lowest allowable capacity and conditions exist that warrant max -
imum temperature stability the controller will pulse the HR relay to energize the evaporator heaters in sequence
with the compressor digital signal.
4.3.14 Frozen Mode - Temperature Control
In Frozen Mode, the controller maintains the return air temperature at set point, the yellow RETURN indicator light is
illuminated, and the default reading on the display window is the return temperature sensor (RTS) reading.
When the return air temperature enters the in-range temperature tolerance (Cd30), the green IN-RANGE light will
energize.
When CnF26 (Heat Lockout Temperature) is set to -10°C, frozen mode is active with set points
below -10°C
(+14°F)
. When CnF26 is set to -5°C, frozen mode is active with set points
below -5°C (+23°F)
.
When the system is in Frozen Mode, the highest priority is given to bringing the container down to set point, the
system will remain in economized operation.
4.3.15 Frozen Steady State
Frozen cargos are not sensitive to minor temperature changes, and the frozen temperature control system takes
advantage of this to greatly improve the energy efficiency of the unit. Frozen range temperature control is accom -
plished by cycling the compressor on and off as the load demand requires.
Once the frozen set point is reached, the unit will transition to frozen steady state (economized operation).
4.3.16 Frozen Idle Mode
When temperature drops to set point minus 0.2°C (0.4°F) and the compressor has run for at least five minutes, the
unit will transition to the frozen idle mode. The compressor is turned off and the evaporator fans continue to run to
circulate air throughout the container. If temperature rises above set point +0.2°C (0.4°F), the unit will transition back
to the frozen steady state mode.
24 VOLT POWER
ENERGIZED
DE-ENERGIZED
TN
ST
F
HPS
CH
IP-CM
TC
CF
TE
IP-EM1
EF
IP-EM2
HTT
TH
HR
ESV
TS
TV EF ES