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Maintenance Bus in A320

Posted: Sun Oct 22, 2017 1:17 pm
by skywalker92
Hello avgeeks,

I got a question about the Maintenance mode on Airbus aircraft. We turn it on if we no longer need the power for cockpit instruments and other main functions. If any cleaning process is carried out in the cabin by cleaners, we turn Maintenance mode ON for them to keep the cabin lights ON and by experience I know that it is possible to operate the cargo doors when the aircraft is in this mode. Can any one please shed some light to find out exactly what things are powered during the Maintenance mode?(I went through the AMM and it does not helped! Hope I have referred the wrong chapter :D)

Regards,
Skywalker92

Re: Maintenance Bus in A320

Posted: Sun Oct 22, 2017 6:58 pm
by StereoTechque
The Maintenance/Service bus powers only those consumers which are necessary for maintenance like cabin lights, Cargo door, cargo door lights avionics compt. lights to name a few.

Re: Maintenance Bus in A320

Posted: Sun Oct 22, 2017 11:07 pm
by Dalmd88
Pretty much the same as the Boeing Ground Service Bus.

Re: Maintenance Bus in A320

Posted: Mon Oct 23, 2017 12:44 am
by skywalker92
Thanks a lot for the answers StereoTechque and Dalmd88.
Do you guys have any document related to this?

Re: Maintenance Bus in A320

Posted: Mon Oct 23, 2017 6:57 am
by Woodreau
I'm surprised the AMM doesn't describe the maintenance bus in the SDS.

from the electrical section of the FCOM, the maintenance bus is comprised of the AC GND/FLT bus, powered directly by external power, with the DC GND/FLT bus powered through TR2.

Not an official source, but a publicly available flight sim resource - Pages 9 and 28 of the following document
http://www.smartcockpit.com/docs/A320-Electrical.pdf

List of items powered by the AC and DC GND/FLT buses from page 28:
-passenger compartment lighting
-galley lighting
-entrance area lights
-lavatory lighting and service
-vacuum cleaner sockets
-flight compartment service outlets
-yellow system hydraulic pump
-flight compartment flood lighting
-fuel quantity indications
-refueling
-cargo hold lighting
-main and nose landing gear compartment lighting
-belly fairing panel service outlets
-ground call
-equipment compartment lights and service outlets
-navigation lights

but even if the maintenance bus wasn't on, you could still operate the cargo door via the yellow hydraulic hand pump.

Re: Maintenance Bus in A320

Posted: Mon Oct 23, 2017 6:37 pm
by fr8mech
I’m sure the AMM has a basic description somewhere, but I would look in the wiring diagram and see who (system-wise) are the users.

Re: Maintenance Bus in A320

Posted: Tue Oct 24, 2017 7:29 am
by skywalker92
I’m sure the AMM has a basic description somewhere, but I would look in the wiring diagram and see who (system-wise) are the users.

yah! It should be, but I was unable to figure it out.
Thanks for the info and doc, Woodreau.