Low fuel alarm system

[avidflyer]

I know there have been a bunch of threads on this topic already, but here is another. I do have the older plastic Kitfox header tank, and it has the one fitting up on the side near the top where I could put this. (yes, I know Kitfox has a much better one that is made out of aluminum, but my plastic one doesn't leak,, yet) I already had some red warning lights so I have one to put in the panel. I did order a red warning light with a real loud buzzer that I may use instead. Today this flow level switch showed up in the mail. Anyone using one of these? Or see any reason why it won't work? It's made for fuel contact. JImChuk

Madison M7750 Plastic Side-Mounted Liquid Level Float Switch, 30 VA SPST, 1/2" NPT Male, 100 psig Pressure: Electronic Component Liquid Level Sensors: Amazon.com: Industrial & Scientific (https://www.amazon.com/gp/product/B009093VDK/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)

https://images-na.ssl-images-amazon.com/images/I/7144CyCSM2L._SL1500_.jpg

[109JB]

Looks very similar to the one Murle Williams shipped with the header tank I bought from him. His was blue, but essentially the same.

[CoClimber]

That's what I'm using. Ask me in a few months how it works when the airplane is flying. I have it going to a warning light that flashes and buzzes. I put a three position switch next to the alarm. Up is on, middle is off, and down is test. Down is a momentary contact - spring loaded to return to the middle position. The idea is that if the alarm goes off, you will be busy getting the plane down and don't need that thing screaming at you.

[Maverick]

I bought one from Murle. I had to bore out the orifice and rethread the tank from Kitfox in order for it to fit. On the tanks Murle fabricates he builds them to use the blue unit he sells. I bought a high output LED light at O'Reilly auto and put it on the dash in a prominent location. I tested it by shutting the auxiliary fuel valves and letting the engine run the header tank down. When the light came on it was very bright. I then opened the auxiliary valves and let the header tank fill back up and the light went out. Subsequently, I was taxiing one day and decided to turn around and go the opposite direction. I applied hard right brake and spun it around and I noticed that the light came on momentarily as the centrifugal force sloshed the fuel all to the right side. It went out as soon as the plane was moving in the new direction. The brightness of the light is very eye catching.

[avidflyer]

Well I finally got around to mounting the low fuel alarm in the Kitfox today. I have the older plastic header tank, and was going to screw the sensor in the upper fitting on the side of the tank. Did that and then when I refilled the header tank, there was about 1/2" of air in the top of the tank. The center part of the tank where the vent line goes out is lower then the ends of the tank by a bit, so the air gets trapped in there. I ended up having to put the sensor in the next lower bung, close to 2" below the top of the tank. I should still have about a gallon of fuel left in the header when the sensor switches on the warning light in the panel. And it will quite likely blink on and off from sloshing fuel in the header tank even before the level would get low enough to turn the light on if all was smooth and still. I had the LED light for the panel, and the switch was just under $25, so I think it was a good investment and it just may save my bacon one day. Well worth it for peace of mind if nothing else. JImChuk

[Kitfox Pilot]

I bought a high output LED light at O'Reilly auto and put it on the dash in a prominent location. I tested it by shutting the auxiliary fuel valves and letting the engine run the header tank down. When the light came on it was very bright. I then opened the auxiliary valves and let the header tank fill back up and the light went out. Subsequently, I was taxiing one day and decided to turn around and go the opposite direction. I applied hard right brake and spun it around and I noticed that the light came on momentarily as the centrifugal force sloshed the fuel all to the right side. It went out as soon as the plane was moving in the new direction. The brightness of the light is very eye catching.


Maverick would you have a part number for the very bright led lights you got? I have been looking at some and don't know good from bad ones. Thanks Harlan

[avidflyer]

I bought some of these warning lights that buzz also. Fairly bright, and make a fair amount of noise. I ended up going with the small red LED light I had though to save some space. JImChuk

2x AD16-22SM AC/DC 12V 22mm Red LED Flash Alarm Indicator Light Lamp With Buzzer | eBay (https://www.ebay.com/itm/2x-AD16-22SM-AC-DC-12V-22mm-Red-LED-Flash-Alarm-Indicator-Light-Lamp-With-Buzzer/193855452174?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)

[jiott]

I don't think I would want the buzzer feature, unless there is a way to turn it off; otherwise it will be buzzing the whole time until you land an fuel up.

[CoClimber]

I don't think I would want the buzzer feature, unless there is a way to turn it off; otherwise it will be buzzing the whole time until you land an fuel up.

That's why I went with a small on/off/test switch so that I could shut off the alarm while I'm panicking trying to get to the airport. Does require that you add it to the check list to make sure it is in the on position.