GENERAL

The aircraft heater, AH74, is a main power operated aircraft cabin interior heater designed to keep warm, heat or ventilate aircraft through the ordinary air condition intake. The fan gives a static pressure of 3,2 kPa, flow operation 3 200 m3/h. The pressure level is flat up to 4 000 m3/h but during today tests, ERRI has decided to optimize the capacity at a flow capacity to 3 200 m3/h.

The interior heater is with these characteristics able to warm keep all types of aircraft regardless of the resistance in the aircraft tubing system. Please note that special arrangements have to be made to avoid a pressure build-up if the aircraft outflow valve is closed on ground, still within aircraft manufacturers pressure limits.

The heater is a result of long experience, ERRI AB was found 1988, and careful studies of aircraft requirements of airflow and pressure. Warm keeping is necessary in order to achieve a non-dew point passage and as consequence give a comfortable temperature in the aircraft. Heating up after a dew point passage has raised the risk for condensation and it takes more power to take condensate water out of aircraft than avoid it happen with warm keeping. The heater will automatically maintain the selected temperature regardless of outside temperature. The temperature selection is set in the PLC-system and can only be changed by reprogramming the system.

125 A at 400 V gives for AH74 double capacity than ERRI interior heater AH 42 that is designed for 63 A. It does not give the double size of aircraft capacity but to follow Boeing 737-800,-900 conditioned air flow requirements, Boeing 5.0 Terminal servicing, it theoretically gives the capacity + 20 deg.C in cabin still with -3X deg.C outdoor and out flow valve 70% Bigger aircrafts, more than 200 seats, can theoretical have same data. Comparable to AH 42,calculated for 160 seats, the new AH 74 give same capacity but for at least 230 seats.

During the start sequence a discharge valve will ensure that there is no pressure in the air hose to the aircraft and at same time prevent cold air from entering the aircraft until sufficient air temperature has been achieved. During stop sequence the discharge valve will ensure that there is no pressure in the air hose to the aircraft. The operator can connect or disconnect the receptacle without any risks. During disconnection phase the fan is still running for cooling the electric elements.

The heater is equipped with a phase sequence control that automatically makes the fan motor run in the correct direction. The weight of the unit is only 380 kg standard equipped and it has large wheels to enable one-man operation.