Avionics News July 2018 - 39

in a current surge of hundreds of amps - prompting an
immediate trip.
The factory where the breaker is made sets the
parameters in its production process - and that setting
is where it stays. While ECBs exist to serve the same
purpose, they fulfill their role in an entirely different
manner. Within the variations of manufacturers, the
components vary little:
* A circuit to measure current in each protected line.
* A microprocessor programmed with the desired trip
points and time delays of each protected circuit.
* A coil controlled by the microprocessor to trip the
circuit.
They generally work like this: When the device senses
excessive current in a circuit, the microprocessor reads
that level and, if seeing the level in excess of where it's
programmed to trip, sends a signal to the coil to open,
or trip the electronic circuit breaker ending the flow of
electricity to that circuit or component.
No moving parts. Depending on the design of the ECB
package, it may use switches simply to signal the ECB
device to close a circuit - rather than sending power to the
device through the switch.

Connected to a compatible primary flight display or
multifunction display, the programming for each circuit -
both the amperage trip level and time delay - can be set
through the PFD or MFD.
Between weight saved, versatility and simplification of
wiring the aircraft, expect to see ECBs advance through
general aviation - as they've already started doing.
The ECBs also provide benefits in maintenance.
An important step before tackling maintenance on
aircraft electrical systems and components involved
deactivating the system in question. Traditionally, the
technician physically pulls a circuit breaker and places
a warning tag or locking collar on the breaker to make
others aware of the system deactivations.
In the Airbus A380, its remote circuit breaker systems,
or RCBSs, allow technicians to call up the power
distribution page of the onboard maintenance terminal,
deactivate a system and install an electronic warning
tag, reactivate, and remove the electronic warning tag.
No physical breaker deactivation is required. And this
system allows for a variety of access points to the RCBS
to accomplish the work, including onboard terminals and
the aircraft's external computer connections. q

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Cockpit Avionics | Test Equipment | Cabin Display and Communications | Engineering Services | FAA Manufacturing and Design Facility

sales@dacint.com | P: +1.512.331.5323 | www.dacint.com

avionics news

july

2018

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Table of Contents for the Digital Edition of Avionics News July 2018