Need help with a Learjet Question
Thread Starter
Joined: Sep 2006
Posts: 94
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From: Middle East
Need help with a Learjet Question
Hi.
I have a quick question hoping someone may know the answer.
I currently Fly the Lear jet31A and was on a trip yesterday when the V-AC which normally is indicating about 110V Was Blinking 10C it had a C in the end, on the Power Monitor Panel. No warning or Caution Light came on but when i went into the Checklist it said the Following.
If the V-AC monitor is haveing a C at the end The Inverters is out of PHASE!!!!
I went into my Flight safety Manual to see what that could have of effect but NO answer. My Mechanic is currently on vecation and not answering his Phone and before i call our 500$ an hour Standby mechanic i was wondering if anyone would know what that really would mean to the safety of the flight if the 2 Inverters is out of PHASE.
Maybe its not that important maybe it is and it must have been one of those parts in my Recurrent training last time i mayyyyy have had my eyes closed lol.
Anyways hope someone might have an idea of what importance it could have on the flight.
Thanks
I have a quick question hoping someone may know the answer.
I currently Fly the Lear jet31A and was on a trip yesterday when the V-AC which normally is indicating about 110V Was Blinking 10C it had a C in the end, on the Power Monitor Panel. No warning or Caution Light came on but when i went into the Checklist it said the Following.
If the V-AC monitor is haveing a C at the end The Inverters is out of PHASE!!!!
I went into my Flight safety Manual to see what that could have of effect but NO answer. My Mechanic is currently on vecation and not answering his Phone and before i call our 500$ an hour Standby mechanic i was wondering if anyone would know what that really would mean to the safety of the flight if the 2 Inverters is out of PHASE.
Maybe its not that important maybe it is and it must have been one of those parts in my Recurrent training last time i mayyyyy have had my eyes closed lol.
Anyways hope someone might have an idea of what importance it could have on the flight.
Thanks
Joined: Jul 2006
Posts: 451
Likes: 2
From: USA
Not sure, but this doesn't sound right...
I know nothing about this, but it just doesn't sound right to me that engineers would try to 'phase' separate inverters. I'm not an electrical engineer, but it seems like that would be tough to do.
Are you sure this is what the book said????
PantLoad
Are you sure this is what the book said????
PantLoad
Joined: Dec 2002
Aviation Qualifications: ATP+Mil
Posts: 3,984
Likes: 568
From: Where the Quaboag River flows, USA
Pant Load:
While what you said makes wonderful sense, he is talking about a LearJet. Engineering there goes by very different standards
I think living with a constant 30 kts of wind has it effects.
While what you said makes wonderful sense, he is talking about a LearJet. Engineering there goes by very different standards
I think living with a constant 30 kts of wind has it effects.
Joined: Oct 2007
Posts: 448
Likes: 0
From: Norfolk U.K.
I don't know anything about Learjets either, but I would have thought that any system with more than one inverter (or rotating alternator) could have problems when they get out of phase. If they are paralleled on a common "bus" a small out of phase condition would lead to higher loads on each inverter and harmonics on the supply. As the phase differential gets worse it would eventually lead to both machines tripping or even failing completely. You are effectively connecting +110 volts to the same bus as -110 volts!
If they were supplying completely separate systems this would not arise, but I assume the normal arrangement is to have them paralleled for redundancy.
If they were supplying completely separate systems this would not arise, but I assume the normal arrangement is to have them paralleled for redundancy.
