Carrier SUPRA 850Mt Operation And Service Manual page 13

2.1 INTRODUCTION
WARNING
Beware of unannounced starting of
engine or standby motor caused by the
unit thermostat or the start/stop cycle.
Personal Protective Equipment : before
doing anything on this product, as
explained in this manual.Always use
safety precautions before doing any
maintenance on the unit
safety glasses
safety shoes
a. System
This manual contains Operating Data, Electrical
Data and Service Instructions for the refrigeration units
listed in Table 2-1. Also Table 2-1 charts some signifi-
cant differences between these models.
The Supra Multi-Temp, multiple compartment refrig-
eration systems offer the versatility of two or three
compartment temperature control in truck. The Multi-
Temp allows the shipper to ship frozen and perishable
commodities in the same load under separate refrigera-
tion control.
b. Truck condensing units
The Supra 750Mt , 850Mt
_
one piece condensing units designed for truck applica-
tions available for R404a refrigerant. They areequipped
with an electric standby motor.
The model/serial number plate is located inside of
the unit on the frame as shown in Figure 2-1 and
Figure 2-2.
SECTION 2
DESCRIPTION
, gloves ,
, safety clothes
and 950Mt models are
_ _
fixed on
the frame
fixed on
the micro
The control system is a microprocessor controller
(Refer to section 2.8 ). Once the controller ( remoteCab
Command within the cab of the truck ) is set at the de-
sired temperature, the unit will operate automatically to
maintain the desired temperature within very close lim-
its. The control system automatically selects high and
low speed cooling or high and low speed heating as nec-
essary to maintain the desired temperature.
The microprocessor controller hasan autostart/stop
feature. The auto start/stop operation provides auto-
matic cycling of thediesel engine, which inturn offers an
energy efficient alternative to continuous operation of
the engine with control of temperature by alternate cool-
ing and heating of the supply air (evaporator outlet air).
A remote standby receptacle is standard with all
units.
c. Multitemperature evaporators
The compartments of the Multi-Temp system are
equipped with separate evaporators.
For Multi-Temp applications, single discharge and
double discharge evaporators are available. The
evaporators aredifferent in size, capacity andnumberof
fans ( see Table 2-2 ), but all work onthe sameprinciple
and use the same single-phase 50Hz/60Hz fan
assembly. The electrical heaters vary according to the
type of condensing unit used and number of
compartments. ( see Figure 2-3 and Figure 2-4 )
The evaporator is constructed with plastic profiles
designed to meet the specific requirements of the
transport industry. The air outlet profiles are designed to
adjust to allow different airspeeds and velocity.
Inside the evaporator housing are one or more of
the following :
240 Volt Single phase backward curved impeller
which supplies high air volumes at low noise levels;
expansion valve; check valve; 12V hot gas solenoid;
12V liquid line solenoid;12V water drain heater;
electrical heater element; sensor ( defrost termination
sensor ); safety heating thermostat.
2-1