Wren 44 Kerostart Supplement
Copyright Wren Turbines Ltd 2012. All rights reserved.
Page
5
Quick start installation - electrical:
Refer to the picture of the ECU on previous page for plug
locations.
Plug burner valve to the 2-pin socket marked as “Gas valve” on
ECU (see top left).
Plug engine fuel valve to adjacent 2-pin socket marked “Fuel
valve” (extreme top left), note – this label is on side of ECU.
Plug in the receiver throttle signal wire from receiver to the plug
marked “Throttle input” (see bottom right).
Plug in the engine rpm sensor to the 3-pin plug marked “RPM
sensor” (bottom right).
Plug in the engine temperature probe to the 3-pin plug marked
“Thermocouple” (bottom right).
Plug in the glow/starter cable from the engine, using extension if
fitted, (see top right).
Plug in the battery/pump cable (top left). Leave the battery end
unconnected at this stage.
Plug in the data terminal (bottom left). A standard servo type
extension cable can be fitted to the model to allow convenient
access, if required.
Setting up ECU (Engine Control Unit)
Remove all rates, mixes and throttle travel settings in the
transmitter. The setup assumes the use of a transmitter with
manual trims.
Digital trims and Throttle-Cut function.
If you have a transmitter with digital trims you can simulate the
trim up/down function using the “Throttle Cut” switch, which is
usually a function switched through a toggle switch mounted on
the transmitter (must not be spring loaded). Consult your radio
manual for this function. Setting the ECU using the “Throttle Cut”
function is done in the same way except that when “trim-up” is
required you switch the “Throttle Cut” to off, and when trim-down
is required, you switch to “Throttle Cut” on.
For initial testing the normal digital trims can be used if you don’t
want to have to explore the “Throttle Cut” function just yet. The
trim up/down function is used to switch the engine to “ready to
start” and “off”, and would not normally be used to vary the idle
rpm. Note - some transmitters may need throttle reversing - see
later.
As the display does not photograph well we have reproduced
the display readings as a green box.
Turn on the transmitter and receiver. On power-up the screen
should come on and after a few seconds should stabilise to the
opening screen and should
show as right:
(If the temp’’ probe is not
connected it will show as 0’C). “T” = ambient temp’.
Trim Low
T=020’C
RPM 00000
PW 000
