Carrier 69NT40-561-399 Operation And Service Manual page 67

CODE # TITLE
Cd48 Dehumidification / Bulb Car-
go Mode Parameter Selec-
tion
Cd49 Days Since Last Successful
Pre-trip
Table 4–3 Controller Function Codes (Continued)
DESCRIPTION
Initially Cd48 will display current dehumidification-mode; bUlb - bulb
cargo mode, dEhUM - normal dehumidification, or OFF - off. This dis-
play is steady.
Pressing ENTER key will take the interface down into a hierarchy of
parameter selection menus (mode, setpoint, evaporator speed, DTT
setting). Pressing ENTER key in any parameter selection menu com-
mits to selection of the currently displayed parameter and causes the
interface to descend into the next parameter selection menu. All pa-
rameter selection menus alternate between a blank display and the
current selection in the right hand display.
Pressing CODE SELECT key in a selection menu cancels the current
selection activity and ascends back up to the next higher selection
menu (or to Cd48 display mode if that is the next higher).
If the operator does not press any key for five seconds the interface
reverts to normal system display and the current selection menu is
canceled, but any previously committed changes are retained.
Available parameters and parameter ranges are a function of configu-
ration options and previously selected parameters as indicated above.
Whenever any pretrip test is initiated, dehumidification-mode goes to
OFF.
Whenever dehumidification-mode goes to OFF:
• Dehumidification control setpoint goes to 0% RH internally but
will then initialize to 95% RH when dehumidification-mode
leaves OFF.
• Evaporator speed select goes to Alt for units without PWM Com-
pressor Control (Cnf57 = Out), Evaporator speed select goes to
Hi for units with PWM Compressor Control (Cnf57 = In).
• DTT setting goes to 25.6°C or 18.0°C, depending on Cnf41.
Whenever dehumidification-mode is set to bUlb, DTT setting goes to
18.0°C if it had been set higher.
Whenever dehumidification-mode is set to dEhUM, DTT setting goes
to 25.6°C or 18.0°C, depending on Cnf41.
For units without PWM Compressor Control (Cnf57 = Out):
• Whenever dehumidification control setpoint is set below 65%
RH evaporator speed select goes to LO if it had been set to Hi.
• Whenever dehumidification control setpoint is set above 64%
RH evaporator speed select goes to Alt if it had been set to LO.
For units with PWM Compressor Control (Cnf57 = In):
• - Whenever dehumidification control set point is set below 60%
RH, the evaporator fan speed is set to LO, the user has the
ability to set the evaporator fan speed to Hi via the keypad.
• - Whenever dehumidification control set point is set equal to or
above 60% RH, the evaporator fan speed is set to Hi, the user
has the ability to set the evaporator fan speed to LO via the
keypad.
Display Only Function - Cd49 is a display only function.
Displays the number of days since last successful pretrip sequence.
Press ENTER to view the number of days since the last successful
pretrip for Auto1, Auto2, and Auto2 in sequence.
Press CODE SELECT to step back through the list and ultimately to
exit the Cd49 display.
4–33 T-365