Danfoss Motor – Motor Bleed Air System Principle


The motor bleed air system supplies air to the air supply mains by means of the motor high pressure compressors 5 and 9 bleed air. The operation of the motor bleed air system is described in detail below the    Danfoss Motor   .


The air supply system is ventilated by 5 stages at low motor speed. At this time, the high pressure stage regulator and the high pressure stage valve are used to control the bleed air pressure; at high motor speed, the bleed air is 9 stages, when the high pressure valve is closed and the 5 stage single Open to the shutter, at which time the bleed air pressure is controlled by the bleed air regulator and the PRSOV. When over-temperature overpressure occurs, the BLEED TRIP OFF light on the P5 board lights up. The 220PSI overvoltage gate is in the bleed regulator, and the 490°F overheating gate is at the PRSOV outlet.


The electromagnetic valve in the BAR is a purely circuit-controlled PRSOV motor component in the order: control panel – ACAU – BAR electromagnetic valve. If there is a situation where the bleed air cannot be connected, the circuit may only be the above.


Component failure. When starting the motor, if the bleeder switch is in the open position, the DEU sends a signal to the ACAU’s start relay to close the BAR solenoid valve, causing the PRSOV to be closed by the spring force.


When over-temperature overpressure occurs, the overheat relay in the ACAU is turned on, and the BAR electromagnetic valve is closed to close the PRSOV by the spring force. At the same time, the main warning light is on, the BLEED TRIP OFF light is on, and the TRIP/RESET circuit is pre-positioned. When the over temperature and overpressure disappear, press the TRIP/RESET switch to reset and PRSOV turns on to continue working. The function of the pre-cooler system is to control the bleed air temperature before bleed air enters the gas source manifold. This system is automatically controlled. The pre-cooler control valve controls the valve opening by the signal of the 390°F temperature sensor and the WTAI electromagnetic valve.