Backup Alternator with Air Conditioning

[FJC]

Hey Everyone,

 

Was wondering if this combination was possible? I think I am finally past my alternator issue but it caused me lots of grey hair and would like a backup solution. I understand the alternator is installed on the accessory pad but I also have an air conditioning compressor there. Those of you that know, please comment!

 

Freddy

[MatthiasArnold]

Ovation 2GX with A/C has this configuration. 
No idea about availability of parts and electrical installation efforts though.

Maybe @JustusSJ can chime in?

Matthias

[JustusSJ]

  On 10/10/2024 at 6:26 AM, MatthiasArnold said:

Ovation 2GX with A/C has this configuration. 
No idea about availability of parts and electrical installation efforts though.

Maybe @JustusSJ can chime in?

Matthias

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Sure ;-)

 

The AC compressor is belt driven off of the starter adapter drive shaft.

The standby alternator is driven by the accessory pad.

[MatthiasArnold]

  On 10/10/2024 at 6:45 AM, JustusSJ said:

Sure ;-)

 

The AC compressor is belt driven off of the starter adapter drive shaft.

The standby alternator is driven by the accessory pad.

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Just found some pics:

Belt driven A/C compressor on the RHS:

Standby alternator attached to accessory panel on the LHS:

[FJC]

Wow...that is a tiny alternator! Seems like adding a backup would work!

 

Thank you!

 

Freddy

[EricJ]

  On 10/10/2024 at 5:20 PM, FJC said:

Wow...that is a tiny alternator! Seems like adding a backup would work!

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They don't put out as much power as the primary alternator, so the expectation is that you may have to shed load down to what it can support, or you'll be draining the battery to meet the excess.

[PMcClure]

Doesn't the Ovation have 2 batteries? I consider that my back up....

[MatthiasArnold]

  On 10/10/2024 at 5:39 PM, EricJ said:

They don't put out as much power as the primary alternator, so the expectation is that you may have to shed load down to what it can support, or you'll be draining the battery to meet the excess.

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Correct - it just delivers a max current of 20A at 28V instead of 100A at 28V. 
Plus you have to increase engine RPM to at least 2400rpm or 2500rpm for the tiny alternator to achieve this output. 

But - at least for the GX this output is sufficient for standard operation of the equipment, otherwise you have to shed load as mentioned by @EricJ  

BTW - a good starting  point for shedding unnecessary load is the A/C blower   

  On 10/10/2024 at 6:04 PM, PMcClure said:

Doesn't the Ovation have 2 batteries? I consider that my back up....

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One certification requirement for TKS/FIKI (and maybe G1000 full glas) is two batteries plus backup alternator (and dual/redundant TKS pumps and heated stall indicator switch and ..). 
 
Best,

Matthias

[FJC]

  On 10/10/2024 at 6:04 PM, PMcClure said:

Doesn't the Ovation have 2 batteries? I consider that my back up....

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I used to feel that way until I went through one battery very quickly (wow, it did not last long considering its only a few months old!). Peace of mind is almost priceless in my mind!

[NickG]

  On 10/10/2024 at 7:38 PM, MatthiasArnold said:

Correct - it just delivers a max current of 20A at 28V instead of 100A at 28V. 
Plus you have to increase engine RPM to at least 2400rpm or 2500rpm for the tiny alternator to achieve this output. 

But - at least for the GX this output is sufficient for standard operation of the equipment, otherwise you have to shed load as mentioned by @EricJ  

BTW - a good starting  point for shedding unnecessary load is the A/C blower   

One certification requirement for TKS/FIKI (and maybe G1000 full glas) is two batteries plus backup alternator (and dual/redundant TKS pumps and heated stall indicator switch and ..). 
 
Best,

Matthias

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No, the requirement for the backup alternator is for FIKI only. That’s one of the main difference between FIKI and Inadvertent - plus a heated stall warning vane.