Danfoss Turbocor TT-300, Руководство по обслуживанию

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M-SV-001-EN Rev.E
Compressor Fundamentals
Liquid refrigerant is internally channeled to
two solenoid valves. These valves have integral
orifices that act as expansion devices to cool
the compressor motor, shaft (rotor) and power
electronics. TT300 and TG230 compressors have
these solenoids arranged so that all components
are cooled in series with each other and the
solenoids act as two stages of cooling capacity.
The TT350, TT400, TT500, TT700, TG310, TG390,
and TG520 compressors and some R-22 TT300
compressors have separate cooling paths for
motor and power electronics. These cooling
methods are identified as serial or split cooling.
Serial cooling has its return suction point to the
inlet of the first stage impeller, thus cooling all
components with refrigerant evaporating at
the main suction evaporation temperature. In
serial cooling versions, solenoid 1 is opened if
any temperature reaches its “turn on” point and
solenoid 2 is opened if any temperature reaches a
second “turn on”point value.
The split cooling has the motor/shaft cooling
circuit return to the first stage impeller inlet and
the power electronics return to the second stage
impeller inlet. This ensures a higher evaporating
(cooling) temperature to minimize condensation
around the power electronic components. In
the split cooling version, solenoid 1 is opened
if either the cavity temperature or the motor
temperature reaches its “turn on” point and
solenoid 2 is opened if the Inverter or silicon
controlled rectifier (SCR) temperature reaches its
“turn on” point.
Medium temperature (MT) version compressors
require their motor cooling suction line to
be vented externally to the main suction line
through an evaporator pressure regulating
(EPR) valve. This valve is required to ensure that
evaporating temperatures cooling the motor
and electronics do not get too cold. The EPR
valve should be adjusted to maintain a minimum
evaporation temperature of 1.5°C (35°F).
Serial Cooling compressors can be identified
by having only one 1/4 inch flare Schrader
connection adjacent to the main motor cooling
liquid connection, while a split cooling model will
have two. These 1/4 inch flare connections access
the refrigerant feeds to the components being
cooled and bypass the solenoid valves. These
ports may be used to inject liquid refrigerant
directly to cool components and enable
compressors to operate during system charging
operations. A minimum pressure ratio of 1.5 and
a full liquid seal at the compressor is required to
ensure proper and correct compressor cooling.
See cooling circuit diagrams: Figure 15
(Compressor Motor and Power Electronics
Cooling (TT300/TG230 Serial Cooling)) and Figure
16 (Compressor Motor and Power Electronics
Cooling (All Models Except TT300/TG230 Serial
Cooling)).
Figure 14 - Cooling Inlet
Adaptors
Prior to Major Revision “E”
TT300 Only
(3/8” with strainer)
Major Revision “E” and Later
(1/2” with strainer)
All Other Models
(1/2” without strainer)