65
Fig. 59 — Economizer Assembly
Fig. 60 — Cutaway Views of the Electronic Expansion Valve
Low Suction Pressure (SPMIN)
The EXV control tries to open up the EXV to increase the suction
pressure and come out of this mode. The SST setting to enter this
mode is dependent on the fluid type. With water the EXV enters
this mode if SST is less than
SST_Freeze
– 6.5°F (
–
21.4°C) in
normal discharge superheat or less than
SST_Freeze
– 18.75°F
(–28.2°C) in low DSH condition. It remains in this mode until
SST is greater than
SST_Freeze
+ 2°F (1.1°C).
SST_Freeze
is
32°F (0°C) for water and freeze set point for brine.
Maximum Suction Pressure (SPMAX)
This mode is disabled for 300 sec after start. The EXV enters
this mode if the SST is greater than 55°F (13°C) and the circuit
is not in DP mode. The EXV closes down to regulate the SST
at about 53.2°F (11.8°C). If the SST is less than 52.3°F
(11.3°C) or the circuit is in DP mode, then the EXV returns to
the normal mode of operation.
ECONOMIZER EXV CONTROL
The economizer EXV is controlled by the SIOB (J18-STPR2). An
economizer gas temperature thermistor (ECT) and an economizer
pressure transducer (EPT) are located in the line running from the
economizer assembly to the compressor. The economizer pressure
is converted to saturated temperature and is used to calculate econ-
omizer superheat. Economizer superheat equals economizer tem-
perature minus saturated economizer temperature. The control
system controls the economizer EXV to maintain the economizer
superheat setpoint, which is approximately 18°F (–7.8°C). The
economizer will start operation when circuit capacity is at 55% or
above. It will turn off at 45%.
EXV TROUBLESHOOTING PROCEDURE
There are two different economizer EXVs. Both of the econo-
mizer EXVs have a total of 2625 steps. There are three differ-
ent main EXVs, which all have a total of 3810 steps. The EXV
motor moves at 150 steps per second. Commanding the valve
LIQUID LINE SHUT OFF VALVE
MAIN EXV
SIGHT GLASS
MAIN FLOW TO EVAPORATOR
ECONOMIZER EXV
FILTER DRIER
BRAZED PLATE HEAT EXCHANGER
(ECONOMIZER)
ECONOMIZER RELIEF
ECONOMIZER FLOW TO COMPRESSOR
1. Cable
2. Glass Seal
3. Motor Housing
4. Stepper Motor
5. Bearing
6. Lead Screw
7. Insert
8. Valve Piston
9. Valve Seat
10. Valve Port
a30-4241
Содержание AquaForce 30XV140
Страница 79: ...79 Fig 76 VFD Communication Wiring Compressor A B Fan VFD A1 A2 B1 B2...
Страница 82: ...82 Fig 81 VFD Compressor Locations 30XV225 325 30XV350 500 30XV140 325 COMPRESSOR A VFD COMPRESSOR B VFD...
Страница 228: ...228 Fig 90 30XV Typical Field Wiring Schematic cont...
Страница 229: ...229 Fig 91 30XV Standard Tier 140 275 All Voltages Power Schematic NOTE See Legend on page 226...
Страница 230: ...230 Fig 92 30XV Standard Tier 300 325 All Voltages Power Schematic NOTE See Legend on page 226...
Страница 231: ...231 Fig 92 30XV Standard Tier 300 325 All Voltages Power Schematic cont NOTE See Legend on page 226...
Страница 232: ...232 Fig 93 30XV Standard Tier 350 500 380 400 415 440 460 575v Power Schematic NOTE See Legend on page 226...
Страница 233: ...233 Fig 93 30XV Standard Tier 350 500 380 400 415 440 460 575v Power Schematic cont NOTE See Legend on page 226...
Страница 234: ...234 Fig 94 30XV High Tier 350 450 All Voltages Mid Tier 350 500 All Voltages Power Schematic NOTE See Legend on page 226...
Страница 235: ...235 Fig 95 30XV Mid Tier 140 All Voltages 160 275 380 400 415 440 460 575v Power Schematic NOTE See Legend on page 226...
Страница 236: ...236 Fig 96 30XV High Tier 140 200 380 400 415 440 460 575v Power Schematic NOTE See Legend on page 226...
Страница 237: ...237 Fig 97 30XV High Tier 140 200 208 230v Mid Tier 160 200 208 230v Power Schematic NOTE See Legend on page 226...
Страница 238: ...238 Fig 98 30XV High Tier 225 325 All Voltages Mid Tier 300 325 All Voltages Power Schematic NOTE See Legend on page 226...
Страница 240: ...240 Fig 99 30XV Communication Wiring...
Страница 241: ...241 Fig 100 30XV 115V Control Wiring All Tonnages All Voltages...
Страница 242: ...242 Fig 101 30XV 24V Control Wiring 30XV140 325 All Voltages...
Страница 243: ...243 Fig 101 30XV 24V Control Wiring 30XV140 325 All Voltages cont...
Страница 244: ...244 Fig 102 30XV 24V Control Wiring 30XV350 500 All Voltages...
Страница 245: ...245 Fig 102 30XV 24V Control Wiring 30XV350 500 All Voltages cont...
Страница 246: ...246 Fig 103 Component Arrangement Diagram for 30XV140 325...
Страница 247: ...247 Fig 103 Component Arrangement Diagram for 30XV140 325 cont...
Страница 248: ...248 Fig 104 Component Arrangement Diagram for 30XV350 500...
Страница 337: ...337 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig L System Information...
Страница 338: ...338 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig M Unit and Language Settings...
Страница 339: ...339 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig N Hand Off Auto This is set in Auto mode for sensorless operation...
Страница 341: ...341 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig P Data Input 2...
Страница 342: ...342 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig Q Data Input 3...
Страница 347: ...347 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig U Pump Wiring Diagram...