Service manual

5
6. GENERAL INFORMATION
This packaged heat pump mounts below the floor of the
vehicle. The innovative design makes it possible to maintain a
smooth, free-flowing roof line for the vehicle. It also relocates
all noise and condensate drainage off the roof to below the
floor of the vehicle.
The heat pump contains a dual compressor system. It
combines the capacity of two roof mounted units into one
highly efficient and compact package.
Each compressor is connected to a separate refrigeration
circuit. The system can be operated with a single compressor
when the air conditioning requirement is low, or with two
compressors when maximum performance is required.
This heat pump operates a two-stage system. The first
compressor and refrigeration circuit is referred to as “1
st
Stage”. The second compressor and refrigeration circuit is
referred to as “2
nd
Stage”. First and second stage will operate
as indicated below.
1
st
stage (the first compressor and refrigeration circuit), will
operate when:
1) The thermostat is demanding cooling or electric
heating,
2) The vehicle is being powered by either shore line or
the on-board generator.
2
nd
stage (the second compressor and refrigeration circuit), will
operate when:
1)
The thermostat senses room temperature that is 2
degrees or higher than the setpoint temperature on
the thermostat.
Switching and control of 1
st
and 2
nd
stage cooling is automatic.
When the cooling demand does not require that both systems
operate, stage two will shut down leaving stage one in
operation. Heat operation always energizes both stages,
however, only stage one operates if power is not available to
circuit #2.
7. THERMOSTAT SPECIFICATIONS
7A. THERMOSTAT - 6535-3451 COLEMAN-MACH SERIES THERMOSTAT
SET TEMP. RANGE: 55 TO 90 DEGREES F.
DISPLAY TEMPERATURE: -20 TO 160 DEGREES F.
SCALE: DEGREES FAHRENHEIT
DISPLAY FORMAT: LIQUID CRYSTAL DISPLAY
RESOLUTION: ONE DEGREE F.
ACCURACY: ± 2% OF DISPLAY TEMPERATURE RANGE
SAMPLING RATE: EVERY 30 SECONDS
POWER SOURCE: 12 VDC NON-REGULATED, NON-FILTERED ± 2 VOLTS
OPERATING TEMPERATURE: -10 TO +55 DEGREE C.
OUTPUT LOAD: 40 mA MINIMUM TO 1.5 AMP MAXIMUM FOR EACH OUTPUT
SAFEGUARDS:
STATIC ELECTRICITY PROTECTION TO END USER AFTER INSTALLATION
ANTI-STATIC PACKAGING TO BE USED FOR SHIPMENT
SPIKE PROTECTION TO 400 VDC ON R+ TERMINAL
CONFORMAL COATING ON P.C. BOARD PROTECTION FROM MOISTURE