초록 ▼

A solid state system for controlling a compressor or pump which is driven by a motor, the compressor being loaded or unloaded manually or automatically and proportionally to maintain a selected suction-pressure setpoint and to maintain the load on the drive motor within a motor-current setpoint limi

A solid state system for controlling a compressor or pump which is driven by a motor, the compressor being loaded or unloaded manually or automatically and proportionally to maintain a selected suction-pressure setpoint and to maintain the load on the drive motor within a motor-current setpoint limit, the system having start-up and shut-down sequences which have timed stages including a delay to permit the building up of oil pressure prior to loading of the compressor and including the automatic loading and unloading of the compressor incident to start-up and shut-down. The control includes monitoring of temperatures and pressures associated with the system and automatic shut-down in response to malfunctions internal to the system, and includes automatic shutdown in response to external malfunctions as selectable options, and further includes separate malfunction indicators with a circuit for providing their operability.

대표청구항 ▼

A control and monitoring system for connection with a fluid compressor driven by a motor and lubricated by an oil pump, the compressor including loading valve means operative to adjust the capacity of the compressor by modulating fluid leakage from its discharge toward its inlet to maintain a desire

A control and monitoring system for connection with a fluid compressor driven by a motor and lubricated by an oil pump, the compressor including loading valve means operative to adjust the capacity of the compressor by modulating fluid leakage from its discharge toward its inlet to maintain a desired suction pressure at the inlet, said system comprising: (a) system control means having an operate position operative to initiate a start-up and run sequence, and having an OFF position operative to stop the compressor drive motor and to initiate a shut-down and stop sequence; (b) an oil pressure failure responsive circuit; (c) a loading actuator and an unloading actuator, said actuators being connected to operate said loading valve means selectively and progressively to load or unload the compressor; (d) first, second, and third delay means sequentially operative after the system control means is set to said operate position respectively to enable the pressure failure responsive circuit to check the oil pressure and reset the control means to OFF position in case of oil pressure failure, and operative to start the compressor drive motor, and operative thereafter to enable the compressor loading actuator; and (e) a shut-down timer initiated when the system control means is reset to OFF position to energize the unloading actuator for an interval long enough to move the loading valve means to an unloaded position.