10
EN
Operation
q
w
8
Securing the Display
q
Display
w
Adhesive Strips
5. Secure the Passport control to the adhesive strips.
7 Operation
NOTICE:
For DX systems only: If your air-conditioning
unit is cool-only, go to parameter P-1, then select COOL
mode (1). Do
not
set the parameter to AUTOMATIC
mode for a cool-only unit. Cool-only units do
not
heat
unless equipped with electric heating. Failure to obey
this notice will cause the unit to cool in both modes. See
“Selecting a Parameter” on page 17.
This section describes the cycle, programming, and
functions for the Passport controls.
I
The images in this section show the Compact
Passport control, unless otherwise indicated. See
“Display Features” on page 4.
7 .1 Understanding the Heating and
Cooling Cycles
The heating and cooling cycles operate differently
depending on the system installed. This section
describes the possible cycles.
I
When used with an optional electric heater, the fan
remains on for four minutes after the heater cycles
off, even if the fan is set to cycled operation.
7 .1 .1 Normal Heating or Cooling Cycle
In AUTOMATIC mode, heating and cooling are supplied
as required to meet the cabin temperature set point.
• The system starts a cooling cycle once the cabin
temperature exceeds the temperature set point by
2 °F (1 °C) and starts a heating cycle once the cabin
temperature falls below the temperature set point by
2 °F (1 °C). The system continues the cycle until the
cabin temperature equals the set point.
• During a cycle, the cabin temperature must drop
below the set point by at least 4 °F (2 °C) before the
system switches from cooling to heating or exceed
the set point by at least 4 °F (2 °C) before the system
switches from heating to cooling. This behavior
prevents small temperature overshoots from causing
the system to switch between heating and cooling
when it is not necessary.
COOL mode supplies cooling only and HEAT mode
supplies heating only.
• The Passport control maintains the cabin
temperature, for either mode, within 2 °F (1 °C) of the
set point by default.
• When satisfying the heating or cooling set point,
the compressor cycles off and the fan returns to low
speed.
In MANUAL FAN mode, the fan speed remains constant.
7 .1 .2 Chilled-Water System Operation
(CW Systems Only)
In CW systems, the water valve does not open unless
the water temperature is adequate to heat or cool
the cabin. The water temperature differential setting
(parameter P-19) defines the adequate heating or
cooling water temperature. See “Selecting a Parameter”
on page 17.
To view the current water temperature, press and hold
Power
and
Up
simultaneously for three seconds.
See “Using the Passport Control Display Panel” on
page 14. The fan remains on low speed until the
adequate water temperature is available.
