MGL Avionics Stratomaster Ultra “L” Owner’s manual
Page 72
RDAC Fuel flow sender installation
Note: Direction of fuel flow
Indicated by arrow on sender
RED wire – Fuel Flow Sender Supply
BLUE wire – Fuel Flow Sender signal
Braid – Fuel Flow Sender Ground
Warning: Incorrect wiring can damage both the RDAC unit as well
as the flow sender. Fuel flow sender part RS 256-225
The optional Fuel Flow Sender is highly recommended for use
with the Stratomaster Ultra. It provides instantaneous readouts of
hourly fuel usage, and both time and distance estimates on
remaining fuel in flight. You can also verify the performance of your fuel pump during the pre-
takeoff engine run up – a very valuable check !
Further, it is possible to set up the Stratomaster Ultra to calculate Fuel remaining by subtracting
fuel used from a value entered when you filled your tank(s).
In this case you may omit the installation of the optional fuel level sender.
Please note that the installation of the Fuel Flow sender should be done in such a fashion that dirt
or debris from the fuel tank cannot lodge inside the flow sender. These will not block you fuel flow
but may lead to the impeller inside the sender jamming. It is usually sufficient to mount the Flow
sender
AFTER
the fuel filter but before the fuel pump. It is a good idea to provide a small
reservoir such as a primer bulb between the flow sender and the fuel pump.
Primer
bulb
or
small
reservoir
Fuel filter
Fuel Tank
As indicated in the recommended fuel flow sender installation drawing, it can be of advantage to
install the flow sender in such a fashion that the inlet points down and the outlet points up. This
prevents vapor from forming a bubble inside the flow sender.
The flow sender is delivered with a small jet that can be installed in the flow sender inlet.
Installation of this jet is recommended for engines with fuel flow rates lower than about 50 liters
per hour. This would apply to most small two and four stroke engines.
Braid
RED
BLUE
Fuel pump
Fuel flow
sender
