Refrigeration Maintenance
10-41
HIGH PRESSURE CUTOUT SWITCH (HPCO) TEST
The HPCO is located on the compressor discharge manifold. If the discharge pressure rises above 470 ± 7 psig (3241 ± 48
kPa), the switch opens the HPCO circuit the to run relay and stops the unit. To test the switch, rework a gauge manifold per the
following illustration.
1. Connect the gauge manifold to the discharge service port with a heavy duty, black jacketed thick wall #HCA 144 hose with
a 900 psig (6204 kPa) working pressure rating.
2. Set the thermostat well below the box temperature so that the unit will be in High Speed Cool.
3. Raise the discharge pressure of the compressor by blocking the condenser coil air flow by covering the condenser with a piece
of cardboard.
NOTE: The discharge pressure should never be allowed to exceed a pressure of 477 psig (3289 kPa) on R-404A/R-452A
systems.
4. If the HPCO opens too soon or does not open to de-energize the run relay and stop the unit, it must be replaced.
HIGH PRESSURE CUTOUT SWITCH (HPCO) REPLACEMENT
Removal
1. Pump down the low side to a 20 in. Hg vacuum (-68 kPa) then stop the unit.
2. Front seat the discharge and suction service valves.
3. Open both service manifold hand valves to bleed the pressure in head into the compressor crankcase. If the pressure balances
in a vacuum, raise the pressure to 1 to 3 psig (7 to 21 kPa) by cracking the discharge service valve.
4. Disconnect the wires and remove the HPCO from the compressor discharge manifold.
1.
Relief Valve
2.
O-ring
3.
Adapter Tee Weather Head
High Pressure Cutout Manifold
Содержание T-1000R
Страница 14: ...Safety Precautions 2 6 Warning Decals 2e24151g0 ...
Страница 18: ...Specifications 3 4 ENGINE CLUTCH Engagement 600 100 RPM Dynamic Torque 66 fT lb 89 5 N m minimum 1600 RPM ...
Страница 34: ...Maintenance Inspection Schedule 4 10 ...
Страница 57: ...Unit Description 5 23 Purge Mode UT Series 1 3 4 5 2 ...
Страница 67: ...Unit Description 5 33 Zone 1 Cool and Zone 2 Cool UT SPECTRUM Units ...
Страница 69: ...Unit Description 5 35 Purge Mode UT SPECTRUM Units ...
Страница 71: ...Unit Description 5 37 Zone 1 Cool and Zone 2 Heat UT SPECTRUM Units ...
Страница 72: ...Unit Description 5 38 ...
Страница 74: ...Diesel Electric Menu 6 28 Adjust Brightness 6 29 Time 6 30 ...
Страница 120: ...Operating Instructions Standard HMI 7 18 ...
Страница 152: ...Engine Maintenance 9 14 T Series Fuel and Oil System Components TK 376 ...
Страница 154: ...Engine Maintenance 9 16 T Series Fuel and Oil System Components TK 270 ...
Страница 156: ...Engine Maintenance 9 18 UT Series Fuel System Components AMA768 ...
Страница 172: ...Engine Maintenance 9 34 T Series Engine Mounting Components for 2 Cylinder Engine ...
Страница 184: ...Engine Maintenance 9 46 ...
Страница 238: ...Refrigeration Maintenance 10 54 ...
Страница 246: ...Clutch Maintenance 11 8 ...
Страница 258: ...Structural Maintenance 12 12 ...
Страница 264: ...Mechanical Diagnosis 13 6 ...
Страница 265: ...14 Electric Standby Diagnosis ...
Страница 268: ...Electric Standby Diagnosis 14 4 ...
Страница 269: ...15 Refrigeration System Diagnosis ...
Страница 272: ...Refrigeration System Diagnosis 15 4 ...
Страница 280: ...Remote Evaporators 16 8 ...
Страница 282: ...Wiring Diagrams and Wiring Schematics 17 2 ...