Long Body Battery relays… probably similar to M20K

[carusoam]

Background…

We have lots of relays…

Some are identical…

1) Master relay…

2) Battery selector relay…

3) GPU relay…

In the two battery system…

Each battery gets a relay mounted next to it…

Prior to engine start… each battery gets selected/voltage tested…

Two of the relays get used briefly every flight, one gets used to supply power depending on the flight and battery condition, or in my case alternating each flight…

The third relay only gets used when the GPU gets plugged in…

Reminder… for anyone considering using the GPU to supply power for avionics set-up and maintenance…. Don’t fear the relay being a weak link… it’s the same as the master relay… 

I spent a few good hours with the Long Body wiring diagrams… nicely hidden at the end of the service manual…

 

Today…

Battery #2 showed no voltage during the test…

A quick trip to the #2 battery access panel… 

Reveals a humming battery relay…

Battery voltage indicates fully charged…

 

Research shows…

Proper replacement is probably a Safran 6041H202 - RELAY

https://peerlesselectronics.com/6041h202-relay?utm_campaign=utm_campaign&utm_content=utm_content&utm_medium=utm_medium&utm_source=utm_source&utm_term=utm_term&utm_campaign=17597120101&utm_source=google&utm_medium=cpc&utm_content=&utm_term=&adgroupid=&gclid=CjwKCAjwq5-WBhB7EiwAl-HEkuIRopN0D71kxqDq4B8EXbZ-8103rNn1dR9cmmPX7ks89xD9SHPLChoCfrUQAvD_BwE

Anyone care to confirm…?

1) No hope in saving bad relays… there isn’t a maintenance procedure…?

2) Best to replace with new…?

 

Next steps…

Inviting @LANCECASPER and @M20Doc for their experience…

Outlook… it is easy access, the logging exercise is probably longer than the actual maintenance…

Fortunately, The Annual is right around the corner…

 

Questions…

Should I purchase the part now so the mechanic has it ready to install?

Anyone familiar with this part, application, or any other insight?

Should I be ready to swap the master relay with near identical times and cycles?

Reference price is about 0.25amus 

Thank you all for your input!

Best regards,

-a-

 

[Guest]

For most two battery airframes the GPG relay and battery relays are the same.  Switching them around should prove the fault.  Just remember to disconnect the battery ground cables before working on them.

Clarence