My 182-S is having a pair of GI-275’s and GFC 500 installed and will have the vacuum pumps removed. Since my vacuum system will be inop, can I legally replace the 3280-1 ammeter/vacuum instrument with an ammeter? If the answer is yes, what gauge would be recommended? If no, I suppose I would have to label the appropriate side of the instrument inop/blank off that side displaying current draw?
Replacing C182 ammeter/vacuum gauge with ammeter only
- Thread starter robin ardoin
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Seems the people installing the 275/500s should be able to answer that and include in their install for you? That would be what I would recommend...
NordicDave
En-Route
Yes you can remove the vacuum gauge if the vacuum system is removed and install a new amp meter.
Strongly consider prioritizing an engine monitor installation. It will pay for itself in saved fuel and heading off engine issues.
Strongly consider prioritizing an engine monitor installation. It will pay for itself in saved fuel and heading off engine issues.
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@NordicDave I have a JPI 830, but obviously I can’t use as primary. I presume as long as it is a PMA’d unit I can replace the combination gauge with an ammeter only instrument?
@Bell206 My avionics tech, who works on whirlybirds at his day job, does fixed wing work after hours in agreement with his employer. He suggested the swap for ammeter only. I just want to make sure I am complying with regulations.
You are. And technically you don't even need a PMA or TSO ammeter as this will be an alteration vs a replacement. However, your guy may want one none the less which is okay. Is he the same person doing the 275/500 install?
Yes, it is the same tech.
rotormatic1
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Rotormatic1
Hard to find replacement ammeter that works with Cessna shunt.
Electronics International VA-1A-300 not work?
https://iflyei.com/product/va-1a-volts-amps-instrument/
https://iflyei.com/product/va-1a-volts-amps-instrument/
NordicDave
En-Route
EI Gauges will work with Cessna Shunts.
Robin, another idea... Why not make a black vinyl semi-circle sticker cover the vacuum half of the gauge? Make or acquire a circle and cut it in half. The vacuum system is gone, it's not even an INOP situation.
That was an option discussed but feels a little ‘cheesy’. LOL. Actually it could be done rather tastefully and much cheaper than the EI gauge. That answers another question I had….. Do I need to label the masked side of the gauge ‘INOP’. I didn’t think so since there will no longer be a vacuum system. Thanks for the advice from all.
Ryan Klems
Line Up and Wait
You would need to special order it, however. The VA-1A-60, their standard 100 or 300 models will not.
Could you explain, in further detail, why the standard -300 would not work? TIA
Ryan Klems
Line Up and Wait
It's works with 50mV shunts, where +50mV is full scale positive flow and -50mV is full scale negative flow at the shunts rated capacity. The "standard" EI shunts are 100A and 300A, so it'll produce +/-50mV at 100A or 300A of in or out current flow. The device has to know what shunt it's working with to display accurate information. The restart Cessna shunt P/N CS3200-1 is a 50mV 60A shunt. If you used that with a -300 EI Ammeter, it would be reading 5x the actual current flow. It's probably just a different firmware load, or maybe jumpers in the unit or something, but there is no non-EI means to change the unit to work with a different shunt.
Thank you Ryan. That explains it perfectly.
No. Have seen it done with a tasteful paint over of the vac portion or a cover of some sort. The vac system removal sign off should take care of any indicator note.
And just to add on the EI, a quick call to their tech support will get you the correct indicator set up for your OEM shunt.