Operating Manual
UL
POWER
UL
260,
UL
350,
UL
390,
UL
520
M0310: OM 260 - 520A01 Revision No: 04
Date:
2021-11-18
Page:
13
of
23
*
Electrical power
Make sure the battery is
fully charged before take-off
(engine not running) with an output voltage
min =
12.7 VDC.
When the engine is running, the (alternator) voltage must be at least 13V.
When the
‘
battery low
’
warning light (see above) is activated during flight (indication
alternator/regulator failure),the flight time with a full battery is ≥3
0 min
4
. At around 10V the ECU
stops functioning and the engine stops.
Attention
:
Never use a “booster” (quick battery charger) to start the engine. Change the
battery to avoid jump starting.
**
Manifold air temperature
Note:
We advise to bring fresh air from outside the cowling to the inlet air filter/manifold. For
turbo engines, we advise to install a suitable intercooler (see installation manual).
Engine
Naturally aspirated
Turbocharged/normalized
Max. at start
60°C (140°F)
5
75°C(167°F)
Max. at take-off
50°C (122°F)
5
70°C (158°F)
Max. in flight
40°C ( 104°F)
5
60°C (140°F)
***
Rail fuel pressure
Rail fuel pressure is the difference or delta pressure ABOVE the Manifold Air Pressure (M.A.P. may
be measured by optional sensor)
Condition
Remarks
A
ECU ON, Engine OFF, Fuel pump(s) ON Fuel pressure (FP) 3
–
3.4 bar (43.5
–
49 PSI)
Fuel pressure must be stable
B
ECU ON, Engine ON, Fuel pump(s) ON
FP depends on MAP/Throttle position
Blue line ideal FP
Idle ±2.6 bar (35 PSI)
WOT ±3.0 bar (43.5 PSI)
nat. asp. engines
WOT ±3.3 bar (48 PSI)
turbo engines
NOTE : Fuel pressure can be higher when using both fuel pumps.
4
Fully charged healthy battery. Depending on installation, used battery/batteries,
aircraft electrical system,… .
5
Rule of thumb : ambient tempe 10°C, with respect to maximum manifold air temperatures
A
B
B
A
A
