AMC 25.1365 Electrical appliances, motors and transformers

ED Decision 2003/2/RM

1.       Heated Domestic Appliances (Galley Equipment)

In showing compliance with CS 25.1365(a), the following should be taken into consideration:

1.1     The design and installation of heated domestic appliances should be such that no single failure (e.g. welded thermostat or contactor, loss of water supply) can result in dangerous overheating and consequent risk of fire or smoke or injury to occupants.

An acceptable method of achieving this is by the provision of a means independent of the normal temperature control system, which will automatically interrupt the electrical power supply to the unit in the event of an overheat condition occurring. The means adopted should be such that it cannot be reset in flight.

1.2     The design and installation of microwave ovens should be such that no hazard could be caused to the occupants or the equipment of the aeroplane under either normal operation or single failure conditions.

1.3     Heated liquid containers, e.g. water boilers, coffee makers should, in addition to overheat protection, be provided with an effective means to relieve overpressure, either in the equipment itself or in its installations.

1.4     When considering failures of domestic appliances, the effect of the loss of the water supply to a water heater, with the electrical supply maintained, should be taken into account.

NOTES:

Due account should be taken of the possible effects of lime scale deposit both in the design and maintenance procedures of water heating equipment.

The design of galley and cooking appliance installations should be such as to facilitate cleaning to limit the accumulation of extraneous substances, which may constitute a fire risk.

2.       Electric Overheat Protection Equipment

In showing compliance with CS 25.1365(d), the following should be taken into consideration:

a.       Failures of any automatic control systems, e.g. automatic timer systems, which may cause the motor to run continuously;

b.       Short circuit failures of motor windings or transformer windings to each other or to the motor or transformer frame;

c.       Open circuit of one or more phases on multi-phase motors;

d.       Motor seizures;

e.       The proximity of flammable materials or fluids;

f.       The proximity of other aeroplane installations;

g.       Spillage of fluids, such as toilet waste;

h.       Accumulation of combustible material; and

i.        Cooling air discharge under normal operating or failure conditions.

3.       Water Systems

3.1     Where water is provided in the aeroplane for consumption, or use by the occupant, the associated system should be designed so as to ensure that no hazard to the aeroplane could result from water coming into contact with electrical or other systems.

3.2     Service connections (filling points) should be of a different type from those used for other services, such that water could not inadvertently be introduced into the systems for other services.