IAI / Mooney Annunciator Panel

[Marc_B]

I updated my annunciator panel with my panel upgrade/AP and it was a learning process to try to understand how these were built and how Mooney wired them.  I learned a lot in the process (as did my install shop and IAI) and thought that I'd share in case anyone needs this for reference.

First off, International Avionics Inc. made the annunciator panels and many voltage regulators for Mooney.  However when they built an annunciator they had several indications that had common location in the row, but many of the indications were built as generic "Positive voltage apply" either with or without dim circuitry.  What this meant is that all the indications that were not mentioned in the Mooney Service Manual were just simple ship voltage apply and were essentially interchangeable.  So Mooney would take an annunciator, wire it how they saw fit depending on the equipment in the aircraft, and then Mooney would create a legend for it based on how it was wired.  Come to find out, the electrical wiring schematic for my serial number shows how Mooney wired my annunciator but this WAS NOT given back to IAI.  So the schematic for your IAI annunciator in their database is a generic build.  VERY important finding for my customization project.

But a bonus of what this means is that many of our indications may be interchangeable.  i.e. start power, alt air, prop deice, pitot heat...these are all "typical positive voltage apply" indications in the MSM.  However there are some of the indications that are more complex.  i.e. Hi/low Vac is two +28VDC (my ship voltage) inputs from high and low vacuum sensors; when the low vac input has +28VDC then it flashes, while the high vac input +28VDC causes it to be solid.  (take a look at the MSM pages attached if you want to see the circuitry and logic).  L/R fuel are the most complicated circuits in the annunciator and are comparator circuits so couldn't be repurposed, but rather had to be removed and replaced.

IMPORTANT NOTE: there are test + and test - pins on the annunciator.  These are left disconnected and unpinned to ship wiring.  These pins are for bench testing with IAI and do not have anything to do with the test button on the face of the unit.  These should never be connected in the aircraft to ship voltage or ground.

Unfortunately when I was going through panel upgrade the two row annunciator limited my ability to keep the GMC507 (AP controller), GTN750 and GTN650 all in the radio stack since the AP controller was much taller than the KFC150 control head.  IAI agreed to make a custom indicator based on the inputs that I still needed.  So this meant that I could get rid of many of the indications that were no longer in use and consolidate to a single row annunciator.  Cost slightly over 2 AMU; call IAI for current pricing.

Original annunciator:

Mockup of single row annunciator legend:

While I had the annunciator sent to IAI, I also was having slight overvoltage issues with my voltage regulators and found out that they were both also IAI so I sent them in as well for recalibration/adjustment.  I spoke with Maxwell and they can't service the ones built by IAI and told me that I'd need to send back to IAI for service.

International Avionics Inc

https://www.internationalavionics.com/

855/417-2820

I worked with Ken Pethe who is the president and with Kenneth Snowden who is their electronics tech.

 

Advanced Aerotechnologies Group at KGXY did my panel.  Certainly would recommend them for avionics and fortunate to have them on my field!

 

Annunciator_MooneyServiceManual.pdf

[Aerodon]

More panel pictures please.  I see an interesting 'thing' you did with your circuit breakers.

The Mooney alternator control units need a 'voltage sense' or maybe 'annunciator power light'.  The problem is they connected this to the field circuit breaker, so just when you might need the annunciator to work, it won't if the field circuit breaker is tripped.

So they came up with the most convoluted and poorly thought out modification I have seen.  Basically disconnect and cap the voltage sense wire at the ACU #1 and install a new wire spliced in at the annunciator power.  Then disconnect and cap the ACU #2 sense wire and piggy back onto the hi/lo vacuum switch.  Then go too the CB's and change these 1A CB's to 2A.

When you really think about what they were trying to do, all it would take is to move this sense wire from the field CB to the Annunciator CB.

You have gone one step further and put this sense wire on its own CB, even better.  But I don't see your over voltage annunciators?  Probably using the engine monitor for over / under voltage, but now you just have one 'system' over voltage instead of individual alternator over voltages?

I'm doing something similar on my 252, but I'm replacing the annunciator panel with Eaton annunciators.  Really expensive, but probably the same cost as your custom annunciator.

 

Thanks for posting.

 

Aerodon

 

 

 

 

 

 

 

 

 

 

 

 

 

[Marc_B]

48 minutes ago, Aerodon said:

I see an interesting 'thing' you did with your circuit breakers.

I think that any change was probably done with the original panel redo before I purchased the aircraft...I'm not entirely sure how this was wired or changed from previous.  But the ammeter and voltage is now digital on the MVP50 with a VOLTS and AMPS field.  But you're right, to test individually you have to cycle the alt field split switch individually.  Dual alternator, dual voltage regulators (which are located at bottom of co-pilot panel and are pretty easily accessible).  I never really thought about it before, but a separate output for each alternator on the MVP would be nice, however I only have one battery.  It would also be interesting to see both total AMP load on the system as well as the total direction of current...i.e. turn on all your equipment and show 20 amps vs showing 0.00 amp as the battery is charged and load handled by alternator.  Of course if your alternator fails, or your engine is off, the amp field shows total load.  So there are ways to get all the information, but you have to use the switches to "dial in" the info you're looking for.

I tossed around the idea of going with a remote xpndr, but had GTX330/GDL88 and it is really pretty out of the way anyways....G500TXi, G5, GTN750/650Xi, MVP-50, GTX330/GDL88, GDL69A SXM, Aera 760...and yes even with all those screens I have an iPad for flight planning. 

48 minutes ago, Aerodon said:

I'm doing something similar on my 252, but I'm replacing the annunciator panel with Eaton annunciators.  Really expensive, but probably the same cost as your custom annunciator.

I looked into that as well as moving the dual row annunciator to top of the copilot side and decided that this was my preferred option overall.  I discovered that the 252 has a flat metal vs Encore tubular structure for the top panel attachment (I think long bodies moved to tubular and so this is similar to a change at that time in general).  So it meant I had less total stack height in the radio stack than the 252.

[Aerodon]

Yes, I am eliminating the hump on the glareshield.  I'm moving the annunciators to in front of the pilot above a G500.

OK so your plane has had 2 upgrades.  Those 'alt sense' wires of to the alternator control units and sense an OV.  Then the ACU provides a voltage to the annunciator.

(careful, different planes had different ACU's etc.)

 

So if you ever need power for your Bose headsets...... use those CB's.

 

Aerodon