Jet Electrical Systems

RogerWilco787

RogerWilco787

Well-Known Member
I am going through ground school and my ground instructor is having trouble explaining things in an easy to understandable manner. I have never flown anything larger than a Piper Seminole, which may be my problem right there, but still...help!!:insane::insane:

Mainly, I don't get what the Integrated Drive Generator (IDG) is/does as well as the Generator Control Unit (GCU), Integrated Control Center (ICC), the Secondary Power Distribution Assembly (SPDA), and the Modular Avionic Unit (MAU). All of this is for the Embraer 170 but I just need a general description of what each thing does.

Thanks in advance
 
Let me help: If it says "AUTO," don't screw with it unless the QRH tells you to screw with it!
 
Not a jungle jet guy, but the IDG is a constant speed drive assembly that regulates the speed off of the N2 spool accessory drive into a constant speed (like a governor on a constant speed prop). The GCU is just that...

That other stuff is just brazilian crap that boils downs to nice round butts in thongs. ;)
 
May be the wrong advice to give because like you, I like to know how everything works inside and out... But I have found that if the instructor doesn't take the time to cover it thoroughly and make sure there are no more questions you probably don't have to know it
 
RogerWilco787 said:
Mainly, I don't get what the Integrated Drive Generator (IDG) is/does as well as the Generator Control Unit (GCU), Integrated Control Center (ICC), the Secondary Power Distribution Assembly (SPDA), and the Modular Avionic Unit (MAU).
Click to expand...

I'll throw my hat into this, no guarantee that I'm correct.

IDG, uses engine spin to create your AC power at 115VAC 400 hz, as you already guessed the engine is fluctuating depending on thrust demands. Now if I remember right you need a piece in there to gear the spin coming off the engine to create a constant spin into the IDG for it to create constant power but that may all be considered part of the IDG.
The Gen control unit, like any gen control unit, monitors power in and out, lets the computer (and pilot) know when power is good, shuts down shorts and checks temp. All kinds of fun stuff. It's one of many magic boxes that works good and lasts long time. Many airplanes have switches for the GCU in the cockpit and they are considered "dusty" switches.
ICC and MAU sound similar to me. Newer aircraft monitor all kinds of different variables, that's what I understand about these avionics units and control centers. Sometimes the info goes to the pilot, sometimes the mechanics want it, sometimes systems want to know which systems are running so they can switch automatically in case one goes down. For instance, in the CRJ, we have no control over the DC system (powered by the AC) and all those little ICC and MAU's will switch power sources around for us seamlessly in the cockpit in case of a short or malfunction.
The PDA's are all kinds of fun. Think of something about half the size of a refrigerator, with electrical bundles running in and out. It's a great way to centralize a lot of grounding points and makes for a perfect place to mount up monitoring and managing devices. A SPDA sounds like the PDA the backup system is built on.

Get into class early and ask this instructor, or at the very least, ask him what you need to know.
 
Pilotforhire587 said:
lol The Dash is caught in between both worlds, a lot of automatic stuff and a lot you have to do yourself... Many times when things start going bizzerk simpling turning it off and back of fixes everything.
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I think that's every plane. Aren't the Dashes made by the same company who manufacturers the Canadian Reset Jet?
 
jynxyjoe said:
I think that's every plane. Aren't the Dashes made by the same company who manufacturers the Canadian Reset Jet?
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Yeah I think back in the Dash 7 days Dehav still owned them, with the design of the Dash 8 Bombardier (canjet) bought them and got together with Boeing for the cockpit design. Next time you see a Dash take a look at the windscreen looks the same as the CRJ. The fuselage of the Dash 8 100 and 200 are very similar to that of the CRJ200
 
Pilotforhire587 said:
Yeah I think back in the Dash 7 days Dehav still owned them, with the design of the Dash 8 Bombardier (canjet) bought them and got together with Boeing for the cockpit design. Next time you see a Dash take a look at the windscreen looks the same as the CRJ. The fuselage of the Dash 8 100 and 200 are very similar to that of the CRJ200
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Yeah, unfortunately I think I'm gonna learn all about the Dash 8 here in a bit. :)
 
RogerWilco787 said:
I am going through ground school and my ground instructor is having trouble explaining things in an easy to understandable manner. I have never flown anything larger than a Piper Seminole, which may be my problem right there, but still...help!!:insane::insane:

Mainly, I don't get what the Integrated Drive Generator (IDG) is/does as well as the Generator Control Unit (GCU), Integrated Control Center (ICC), the Secondary Power Distribution Assembly (SPDA), and the Modular Avionic Unit (MAU). All of this is for the Embraer 170 but I just need a general description of what each thing does.

Thanks in advance
Click to expand...

These are all general questions...Have they handed out the systems manual yet? If so, you need to read the electrical system again and again until you get it. Im not a systems wizard, but if you have more specific questions id be glad to help. Also, im sure some of the systems of other airplanes are similar, but you really need to ask an Embraer guy about an embraer plane bc you dont want any negative learning. What airline?
 
IDG is a the whole package that contains the Constant Speed Drive, Generator, and each has Generator Control Unit. It is physically attached to an belt of the engine and can be disconnected from the engine via the switches in the cockpit, it can not be reconnected in flight.

ICC (Integrated Control Center). Are located in the electronics bays, there are 4 of them. They Contain the BUS's (AC1, AC2, DC1, etc...), as well as thermal circuit breakers (not accessible to crew).

SPDA Secondary Power Distribution Assemblies. It gets power from the ICC's and then distributes it to the other aircraft systems.
Is a load management unit, it contains the electronic CB's (controlled from the MCDU).

MAU (Modular Avionics Units), Cabinets that contain various system modules (FMS, Stall protection, Autopilot, etc..). There are 3 and located in the Ebays.

So essentially, The GCU controls the Actual Generator, if it likes the output it closes the relay and sends the power to the ICC's. The ICC's look a the power, and powers its BUS's (The BUS's are part of the ICC). From the ICC BUS's it goes to the systems or goes to the SPDA's. The SPDA's distribute the power through the electronic CB's to the appropriate systems. The MAU's contain various aircraft modules.

Clear as mud, and no one ever asked about them on the oral other than can you reconnect an IDG in flight and Where are the Electronic CB's controlled from. Still good to know.

PS I cheated and looked at the manual in order to make sure I wasn't giving you crap info.
 
So much for yelling over your shoulder ' hey Eng! '...

Sent from my 1989 Motorola StarTAC using Tapatalk
 
BlueMoon said:
IDG is a the whole package that contains the Constant Speed Drive, Generator, and each has Generator Control Unit. It is physically attached to an belt of the engine and can be disconnected from the engine via the switches in the cockpit, it can not be reconnected in flight.

ICC (Integrated Control Center). Are located in the electronics bays, there are 4 of them. They Contain the BUS's (AC1, AC2, DC1, etc...), as well as thermal circuit breakers (not accessible to crew).

SPDA Secondary Power Distribution Assemblies. It gets power from the ICC's and then distributes it to the other aircraft systems.
Is a load management unit, it contains the electronic CB's (controlled from the MCDU).

MAU (Modular Avionics Units), Cabinets that contain various system modules (FMS, Stall protection, Autopilot, etc..). There are 3 and located in the Ebays.

So essentially, The GCU controls the Actual Generator, if it likes the output it closes the relay and sends the power to the ICC's. The ICC's look a the power, and powers its BUS's (The BUS's are part of the ICC). From the ICC BUS's it goes to the systems or goes to the SPDA's. The SPDA's distribute the power through the electronic CB's to the appropriate systems. The MAU's contain various aircraft modules.

Clear as mud, and no one ever asked about them on the oral other than can you reconnect an IDG in flight and Where are the Electronic CB's controlled from. Still good to know.

PS I cheated and looked at the manual in order to make sure I wasn't giving you crap info.
Click to expand...

You beat me too it. I was just about to pull out my old 170 manuals myself. BTW don't let them tell you can't have a tripple MAU failure. It has happened.

HeyEng said:
So much for yelling over your shoulder ' hey Eng! '...

Sent from my 1989 Motorola StarTAC using Tapatalk
Click to expand...

LOL...Hey Eng CHECK ESSENTIAL...

I love the old voice activated planes....................Whatever the pilot says the FE does...
 
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