Aerospace relays are electronically controlled devices that open and close electrical contacts to affect the operation of other devices in the same circuit or another circuit.The relay converts electrical energy into mechanical energy in various ways and through a mechanical link, driving the electrical conductor (contact) of the control circuit ).Solid-The status relay can also be used for electrical switch applications.a.Use of aerospace relaysMost relays are used as switching devices that can reduce weight or simplify electrical control.It should be remembered that the relay is an electric switch, so a pressure drop occurs under low system voltage conditions.b.Connection type.Relays are manufactured in a variety of connection modes from mechanical to plugin devices.The installer varies depending on the connection type and should follow these procedures to ensure the correct operation of the relay.c.Repair.Relays are complex mechanical and electrical components, most of which are unfixable.d.Relay selection.(1) as described on the relay housing, the contact ratings only describe the manufacturing, carrying and disconnection capabilities of the resistance current.Please consult the appropriate specifications to determine the drop factor for other types of current loads.(Ref.MIL-PRF-39016, MIL-PRF-5757, MIL-PRF-6016, MIL-PRF-835836.) (2) operating the relay below the nominal Coil voltage may impair its performance and should never do so without the manufacturer's written approval.e.Installation and maintenance of aerospace relays.For installation and maintenance, care should be taken to ensure the proper placement of the hardware, especially at the electrical connection.It is highly recommended to use a properly calibrated torque wrench and follow the manufacturer's installation procedures.This is a particularly important sealed relay because of the glassto-Metal seals (for insulation of electrical "charged" components) are particularly prone to catastrophic failure due to excessive bending.(1) when replacing a relay in an ac (ac) application, it is critical to maintain the correct phase sequence.For any application involving plug-insIn relays, the correct participation of their retention mechanisms is critical.(2) the proximity of certain magnetic permanent magnet auxiliary coils to operate relays may cause them to interact with each other.Any manufacturer's advice or precautions must be followed closely.Air switch.Load considerations.When an aerospace switch or aerospace relay is used in applications with a current or voltage far below the rated conditions, additional intermediate tests should be performed to ensure reliable operation.Contact the manufacturer on applications different from the rated conditions.Operating conditions of switches and relays.Aerospace switches and aerospace relays should be compared to their specification ratings to ensure that all contacts are properly manufactured under all operating conditions, including vibration equivalent to the area of the aircraft where the switch or relay will be installed.