Danfoss Performer SH090 Selection & Application Manuallines

Also see for Performer SH090: Instructions Instructions Application guidelines Application guidelines Application guidelines

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Danfoss Performer SH090 Selection & Application Manuallines Manual pdf 26 page image

APPLICATION GUIDELINES26 FRCC.PC.007.B5.02O PERATING CONDITIONSDGT protection is required if the high and lowpressure switch settings do not protect the com-pressor against operations beyond its specific ap-plication envelope. Please refer to the examplesbelow, which illustrate where DGT protection isrequired (Ex.1) and where it is not (Ex.2).A discharge gas temperature protection devicemust be installed on all heat pumps. In revers-ible air-to-air and air-to-water heat pumps thedischarge temperature must be monitoredduring development test by the equipmentmanufacturer.The DGT should be set to open at a discharge gastemperature of 135°C.The compressor must not be allowed to cycleon the discharge gas thermostat. Continuous op-erations beyond the compressor’s operating rangewill cause serious damage to the compressor!A high-pressure (HP) safety switch is required toshut down the compressor should the dischargepressure exceed the values shown in the tablesection "System pressure test". The high-pressureswitch can be set to lower values depending onthe application and ambient conditions. The HPswitch must either be placed in a lockout circuitor consist of a manual reset device to prevent cy-cling around the high-pressure limit. If a dischargevalve is used, the HP switch must be connected tothe service valve gauge port, which must not beisolated.High and lowpressure protectionThe SH380 incorporate an internal relief valve setto open between the internal high and low pres-sure sides of the compressor when the pressuredifferential between the discharge and suctionpressures surpasses 31 to 38 bar.This safety feature prevents the compressor fromdeveloping dangerously high pressures shouldthe high pressure cut-out, for whatever reason,fail to shut down the compressor.Internal pressure relief valveHigh pressureThe discharge gas temperature must not exceed135°C.The discharge gas thermostat accessory kit (code7750009) includes all components required for in-stallation as shown below. The thermostat mustbe attached to the discharge line within 150 mmfrom the compressor discharge port and must bethermally insulated and tightly fixed on the pipe.Discharge temperatureprotection70656055504540353025201510-30 -25 -20 -15 -10 -5 0 5 10 15 20Cond. temp. (°C)Evap. temp. (°C)LP1HP2HP1R410ADGT - limit Example 1Example 2LP2Example 1 (R410A, SH = 11 K)LP switch setting:LP1 = 3.3 bar (g) (-15.5°C)HP switch setting:HP1 = 38 bar (g) (62°C)Risk of operation beyond the applica-tion envelope.DGT protection required.Example 2 (R410A, SH = 11 K)LP switch setting:LP2 = 4.6 bar (g) (-10.5°C)HP switch setting:HP2 = 31 bar (g) (52°C)No risk of operation beyond the ap-plication envelope.No DGT protection required.Discharge lineInsulationBracketThermostatHPLP Relief valve