Alternator Switch

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raknal
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Joined: 26 Apr 2010, 17:12

Alternator Switch

Post by raknal »

I am unable to locate the alternator switch, and on page 91 of the manual it states with alternator failure to turn of the ALT switch for a second then on.

My reason to locate the switch is my ammeter always show 0 amps so I am assuming i have an alternator failure as per page 91 of the manual "Alternator Failure"

Raknal

J van E
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Joined: 28 Aug 2013, 15:46

Re: Alternator Switch

Post by J van E »

The Comanche doesn't have an ALT switch... and my meter also always shows 0. Don't know if this is a bug or not. Maybe that alternator info from the manual was accidently copied from another manual...?
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Scott - A2A
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Re: Alternator Switch

Post by Scott - A2A »

Correct there is no alternator switch in the Comanche. The ammeter will normally show 0 amps when the engine is running except after using the starter and the battery is charging for some time.

The ammeter shows amps from the alternator to the battery (charging) or from the battery to the airplane (when the alternator is off, or in the case of the Comanche without an alternator switch, when the battery is off).

To see the draw from the airplane on the battery on the Comanche when the engine is running, just pull the GEN breaker below the cockpit on the left and you will see the ammeter needle go into the negative, showing the airplane drawing power from the battery based on the electrical load.

Scott.
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Flyfox
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Re: Alternator Switch

Post by Flyfox »

Scott - A2A wrote:Correct there is no alternator switch in the Comanche. The ammeter will normally show 0 amps when the engine is running except after using the starter and the battery is charging for some time.

The ammeter shows amps from the alternator to the battery (charging) or from the battery to the airplane (when the alternator is off, or in the case of the Comanche without an alternator switch, when the battery is off).

To see the draw from the airplane on the battery on the Comanche when the engine is running, just pull the GEN breaker below the cockpit on the left and you will see the ammeter needle go into the negative, showing the airplane drawing power from the battery based on the electrical load.

Scott.
So, how is the pilot supposed to check the alternator function? And how come the manual gives so precise instructions about a switch which is not at all present? Have I overlooked something?
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Oracle427
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Re: Alternator Switch

Post by Oracle427 »

If the amperage is negative, the alternator is not working and the battery is discharging. If the amperage is 0 or positive, then the alternator is working.
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Flyfox
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Re: Alternator Switch

Post by Flyfox »

Sounds reasonable. Thanks, Oracle,
Felix

J van E
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Joined: 28 Aug 2013, 15:46

Re: Alternator Switch

Post by J van E »

Flyfox wrote:So, how is the pilot supposed to check the alternator function? And how come the manual gives so precise instructions about a switch which is not at all present? Have I overlooked something?
As I posted the information about the alternator was accidently left in the Comanche manual: a lot of the information in the various manuals for the various planes is shared. A2A shared a bit too much in this case. :wink:
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