![background image](http://html1.mh-extra.com/html/carrier/vector-1800-mt/vector-1800-mt_operation-and-service-manual_2564194092.webp)
62-11039
4-5
4.4.2 PULSE COOL MODE
When Frozen Priority Cooling is not used Pulse Cool
Mode is available. When any compartment has a
setpoint in the frozen range, and another compartment
has a setpoint in the perishable range, and the
perishable compartment temperature falls to within 2.3
_
F (1.3
°
C) above setpoint, the perishable compartment
will go into Pulse Cool Mode to drop the cooling capacity
in that compartment. During Pulse Cool Mode, the
EVXV (Compartment 1) or the LSV (Compartments 2
and 3) for the perishable compartment will be open for 4
seconds, then close for 26 seconds. This 30 second
cycle will repeat itself as long as the perishable
compartment temperature remains between 2.7
_
F
(1.5
°
C) and 1.5
_
F (0.8
°
C) above setpoint. Should the
return air temperature rise more than 2.7
_
F (1.5
°
C)
above setpoint in any perishable compartment, that
compartment will go into Cool Mode. Should the
temperature fall to 1.5
_
F (0.8
°
C) above setpoint, that
compartment will shut off.
4.4.3 PRIORITY MODES
There are 2 priority modes: Frozen Priority Cooling
Mode and Perishable Priority Mode.
a. Frozen Priority Cooling
Parameters are available in the Configuration List to
enable Frozen Priority Cooling.
The selection for
Frozen Priority Cooling allows both the Frozen and
Perishable Priority Cooling Modes to operate. When
enabled, these modes give refrigeration system
capacity priority to the compartment(s) with frozen
setpoints during the Frozen Priority Cooling Mode, and
divides the capacity between the frozen and perishable
compartments during Perishable Priority Cooling.
Priority Cooling Modes only operate once the
compartment temperature for the compartment(s) with
setpoints in the frozen range are below 32
_
F (0
°
C), and
at least one other compartment has a setpoint in the
perishable range, and that compartment is calling for
cooling.
Frozen Priority Cooling provides additional cooling
capacity in the frozen compartment(s) by allowing
normal cooling operation in those compartment(s), and
by turning off the Compartment 1 evaporator fan motors
and closing the Compartment 1 EVXV or the LSV (in
Compartment
2
or
3
evaporators),
for
all
compartment(s) with a setpoint in the perishable range
for the length of time selected as the Frozen Priority
Timer. This time can be set from 5 to 60 minutes. The
factory setting is 5 minutes. After the unit has operated
in Frozen Priority Cooling for the set number of minutes,
the unit will change to Perishable Priority Cooling mode,
and will operate in this mode for the length of time
selected as the Perishable Priority Timer. This time can
also be set from 5 to 60 minutes, and has a factory
setting of 5 minutes.
Perishable compartment temperature protection during
Frozen Priority Cooling is possible by using the
Perishable Priority Temperature Override setting in the
configuration list. This value can be set for Off, or for
3.5
_
F (1.9
°
C) to 27
_
F (15
°
C) in .5 increments.
Perishable Priority Temperature Override watches the
box temperature in the perishable compartment(s),
during the time that the frozen compartment(s) are
operating in Frozen Priority Cooling. After the first 5
minutes of Frozen Priority Cooling, the control looks at
how far the return air temperature in the perishable
compartment(s) are from setpoint. Once the return air
temperature is more than the value selected for
Perishable Priority Temperature Override, the Frozen
Priority Cooling cycle will end, and the unit will operate in
Perishable Priority Mode.
b. Perishable Priority Mode
During Perishable Priority Mode, the evaporator fans
will be on in all compartments. Compartments with
return air temperatures below setpoint will operate in the
heat cycle. Compartments with return air temperatures
above setpoint will operate in a modified cool mode.
Compartments with frozen setpoints will cool
continuously.
Compartment(s) with perishable
setpoints will operate by opening and closing the EVXV
(Compartment 1 only)
or the LSV (remote
compartments) to limit the refrigerant flow to those
compartments. The EVXV or LSV will be open for 8
seconds, then close for 12 seconds, then the cycle will
be repeated until the compartment no longer is calling
for cool, or the timer puts the unit back into Frozen
Priority Cool Mode.
4.4.4 SUPPLY AIR LIMIT CONTROL
Supply Air Limit Control is available for setpoints above
+32
_
F (0
_
C) only.
In a 2--Compartment system, Supply Air Temperature
Control is always available for Compartment 1 and may
also be available for Compartment 2, but only when a
SAT sensor is installed in the Compartment 2
evaporator. For 3--Compartment units, Supply Air
Temperature Control is only available in Compartment
1.
Supply Air Temperature Control is selectable for both
Continuous Run and Start/Stop Operation.
Two
configurations allow the user to determine what the
Supply Air Temperature limit(s) will be.
Configuration “Supply Air Limit S/S” is the limit for the
Supply Air Temperature when the unit is operating in
Start/Stop.
The default value is –10.8
_
F (--6
_
C),
meaning that the Supply Air Temperature is allowed to
go 10.8
_
F (--6
_
C) below setpoint during temperature
pulldown.
Configuration “Supply Air Limit Cont” is the limit for the
Supply Air Temperature when the unit is operating in
Continuous Run. The default value is –9
_
F (--5
_
C),
meaning that the Supply Air Temperature is allowed to
go 9
_
F (--5
_
C) below setpoint during temperature
pulldown.
Summary of Contents for VECTOR 1800 MT
Page 1: ......
Page 2: ...OPERATION SERVICE MANUAL for VECTOR 1800 MT Trailer Multi Temp Refrigeration Units ...
Page 19: ...1 5 62 11039 1 3 SAFETY DECALS ...
Page 20: ...1 6 62 11039 62 03958 00 Heat Warning 62 03957 01 High Voltage 62 60280 00 Standby Safety ...
Page 21: ...1 7 62 11039 ...
Page 303: ...10 1 62 11039 ...
Page 310: ...10 8 62 11039 BASED ON ENGINEERING SCHEMATIC 62 60926 REV G NEXT SHT ...
Page 311: ...10 9 62 11039 FROM PREVIOUS SHT ...