Thermo King MD-MT, Operator'S Manual

Page: 33 / 192

Unit Description
33
Zone 1 Cool and Zone 2 Cool
High pressure refrigerant vapor leaves the
compressor and flows through the open CIS to the
condenser where the refrigerant condenses into
high pressure liquid. The liquid refrigerant flows
through the receiver tank into the liquid lines.
The LLS is open so some of the refrigerant flows
through the Zone 1 expansion valve into the Zone
1 evaporator. There liquid refrigerant cools the
Zone 1 evaporator as it evaporates into low
pressure vapor. The refrigerant returns to the
compressor through the SLCV and the
accumulator.
The RLLS is also open so some of the refrigerant
flows through the Zone 2 expansion valve into the
Zone 2 evaporator. There liquid refrigerant cools
the Zone 2 evaporator as it evaporates into low
pressure vapor. The refrigerant returns to the
compressor through the RSLS, the Zone 2 suction
line, the RSLCV, and the accumulator.
Zone 1 Evaporator
1F:
Zone 1 Liquid Line Solenoid (LLS)—Open
2F:
Zone 1 Liquid Return Check Valve (LRCV)—
Closed
3F:
Zone 1 Suction Line Check Valve (SLCV)—
Open
4F:
Zone 1 Suction Line Solenoid (SLS)—Open
5F:
Zone 1 Hot Gas Solenoid (HGS)—Closed
Zone 2 Evaporator
1R:
Zone 2 Liquid Line Solenoid (RLLS)—Open
2R:
Zone 2 Liquid Return Check Valve
(RLRCV)—Closed
3R:
Zone 2 Suction Line Check Valve
(RSLCV)—Open
4R:
Zone 2 Suction Line Solenoid (RSLS)—
Open
5R:
Zone 2 Hot Gas Solenoid (RHGS)—Closed
Condensing Unit
6:
Condenser Inlet Solenoid (CIS)—Open
7:
Condenser Inlet Check Valve (CICV)—Open
8:
Condenser Check Valve (CCV)—Open
9:
Receiver Tank Pressure Solenoid (RTPS)—
Closed
10:
Purge Valve (PV)—Closed
11:
Purge Check Valve (PCV)—Closed
Figure 3: Zone 1 Cool and Zone 2 Cool
AEA2086
Zone 2 Cool
Zone 1 Cool
Condensing Unit