New Fuel Senders-SSL 470!

[roger]

Hey, I just had a new SSL come across my email today, it looks like Piper finally sourced some new build fuel senders for our airplanes-looks like Aviall has various amounts of them in stock at $430 each.

Attachments:

SSL 470.pdf (132.63 KB)

[ronnie27478]

I had the inner sender on the right AUX (outboard) tank go open.  When measuring the outboard sender on the same rank, I read around 2 ohms with the tank full.  I expected this to be higher and to go to 0 as the tank drained.

Anybody know what the resistance reading of various senders should be with associated tank full and tank empty should?  Any of the following question marks you can fill in would be appreciated.

Main (inboard) tanks, outboard sender:    ? ohms full, ? ohms empty
Main (inboard) tanks, inboard sender:    ? ohms full, ? ohms empty

Aux (outboard) tanks, outboard sender:    ? ohms full, ? ohms empty
Aux (outboard) tanks, inboard sender:    ? ohms full, ? ohms empty.


Also it looks like the associated fuel gauge was damaged, maybe when output tank  was selected.  I now reads only about 1/2 when the tank is full.  Any experience with this?

Thanks,
Ronnie

[gsimmer]

I believe they are either 0 to 200 ohms or 0 to 300 ohm units. They should read 0 ohms when the sending unit is at its lowest or empty

[ronnie27478]

Thanks for the response. On my right side, which is working correctly, I measured 92.8 ohms on the MAIN (inboard) tank when full and 121.5 ohms on the AUX (outboard) tank when full. Each tank has two senders wired in series. All four senders have a different part number and I don't know how the resistance is divided between each sender in a tank. If the range is the same, then I would guess that each sender ranges from 0 ohms when empty to 50 ohms when full.

I now need to decide on buying the new parts mentioned above or getting Air Parts of Lock Haven to repair/overhaul them.

I will update with what I learn once I get new ones or repaired ones.

Thanks,
Ronnie

[gsimmer]

Ronnie

I will check what the range is on my units tonight. I sent all eight of my units out to air parts when I put my Auracle system in three years ago. Within a year, I replaced three units the first time and I just replaced another three of them last week. Of course out of warranty. I just bought three new ones from instrument tech for the same price as the overhauls from air parts. I did have a couple that were showing an open when the sending units were at one end of the range. They replaced with no questions asked. Another thought is to look at CIES sending units (https://ciescorp.net/). I believe that it will require all the units being replaced at the same time and an extra wire being pulled for power and ground. These units use a magnetic pickup and you won't run into the issues with the 1930 technology of these resistor type units. I wish I would of done this originally when I sent all eight of mine in for overhaul.

[ronnie27478]

I contacted Instrument Tech Corp via www.shipinstrumenttech.com. Bill Prewitt there was very quick to respond and provide this information:

Fuel gauge senders, Main (inboard) tanks:
Outboard sender: Piper PN 40648-02 -> PS50149-2: Empty 0 – 0.5, Full 38 to 42 ohms
Inboard sender: Piper PN 40648-03 -> PS50149-3: Empty 0 – 0.5; Full 48 to 52 ohms

Fuel gauge senders, Aux (outboard) tanks:
Outboard sender: Piper PN 40648-04 -> PS50149-4: Empty 0 – 0.5, Full 38 to 42 ohms
Inboard sender: Piper PN 40648-05 -> PS50149-5: Empty 0 – 0.5; Full 48 to 52 ohms