Aircraft circuit breaker series 4120 now with MS approval

Citation

(2001), "Aircraft circuit breaker series 4120 now with MS approval", Aircraft Engineering and Aerospace Technology, Vol. 73 No. 2. https://doi.org/10.1108/aeat.2001.12773bad.006

Aircraft circuit breaker series 4120 now with MS approval

Aircraft circuit breaker series 4120 now with MS approval

Keywords ETA circuit breakers, Circuit breakers

ETA informs us that it has added the important American MS3320 to its list of approvals for the series 4120 aircraft circuit breaker which is designed especially to meet the needs of commercial aircraft.

The ETA 4120 is described as a temperature-compensated, single-pole thermal aircraft circuit breaker. It now has approval to the American standard MS3320, complementing the existing EN and various customer specific approvals. Intended for commercial aircraft applications, the 4120 is available in a wide range of current ratings from 0.5A to 25A, all in the same case size, and claims to have the lowest mass of any product of its type currently on the market. It is stated to be qualified for operation in ambient temperatures between –55°C and +125°C.

The threadneck, panel-mounted design features push/pull, on/off manual actuation with an indicator band clearly indicating the tripped/off position. It is said to operate at very precise conditions of overcurrent. This reportedly prevents the destruction of wiring and components in the protected circuit and minimises the smoke and fire risks that overheating can cause. A high tolerance to sudden current surges is reported to be in-built, reducing the risk of nuisance operation, and enabling an optimum match of cable size to circuit breaker rating with weight and cost saving benefits. By resetting the circuit breaker button, the circuit can be immediately repowered if desired.

For critical applications, especially in helicopters and combat aircraft where random vibration can be a special problem, the ETA series 483 claims the highest performance specification aircraft circuit breaker available. It has a novel tease-free operating mechanism and two chamber construction, which lead to even greater safety and reliability. Current ratings can be supplied between 1A and 35A, all in the same size housing, and the range also includes an MS3320 approved version.

Further details are available from ETA Circuit Breakers Ltd. Tel: +44 (0)1296 420336; Fax: +44 (0)1296 488497.