Operation Manual

8120 Installation and Operation Manual84
B-2 GPS navigation problems
2-1 No GPS fix or long time to get fix at
startup:
a May occur occasionally if the antenna
does not have a clear view of the sky. The
satellite positions are constantly changing.
b Antenna cable not connected to display
unit.
2-2 Instrument GPS position different from
true position by more than 10 m (33 ft):
a Instrument in simulate mode. Turn
simulate mode off (see section 17-14).
b The normal error in GPS position will
exceed 10 m (33 ft) for about 5% of the
time.
c Under special circumstances the US
Department of Defence may introduce a
deliberate and changing error in the GPS
positions of up to 300 m (1000 ft).
2-3 Instrument position different from
same position on local charts:
a Instrument in simulate mode. Turn
simulate mode off (see section 17-14).
b Incorrect chart datum. Select the correct
chart datum (see section 17-2).
c Map shift has been applied wrongly. Clear
map shift, then reapply if necessary (see
section 17-2).
2-4 Can not see boat on chart:
Press
ESC
to switch to centre on boat
mode (see section 3-2-1).
2-5 The time or date on satellite display is
wrong or off:
a No GPS fix.
b In simulate mode. Turn simulate mode off
(see section 17-14).
c Local time offset is wrong (see section
17-12). The Local Time Offset must be
changed when daylight saving time starts
or ends.
2-6 Autopilot not responding to
Instrument; no NMEA output:
a NMEA output disabled or the required
NMEA sentences are not turned on. Check
NMEA settings (see section 17-10).
b Check that the instrument is connected
correctly.
2-7 No DGPS fix or loss of DGPS fix:
a To receive a DGPS fix, WAAS/EGNOS must
be enabled or an optional DGPS antenna
fitted (see section 7).
b With WAAS/EGNOS: Boat out of coverage
area (see section 7).
c With WAAS: GPS antenna does not have
a clear view of the horizon towards the
equator.
b With beacon DGPS: boat out of range of a
DGPS beacon.
3-1 Fuel used or remaining seem
inaccurate:
a Instrument is not wired for auto power
(see section 18-4).
b In rough seas, fuel may surge back
and forth through the fuel transducer,
resulting in incorrect readings. Try
installing a one-way valve between the
fuel transducer and the fuel tank.
B-3 Fuel consumption problems
c The Set remaining fuel value must
be reset after every refuelling (see section
12-1).
d The fuel tank may not refill to the same
capacity each time due to air pockets.
This is particularly noticable with
underfloor tanks.
e Fuel transducers wear out over time and
should be replaced after every 5000 litres
of fuel.