PART I - DESCRIPTIVE
inertia switches operate, the batteries are automatically
isolated irrespective of the position of the battery master
switch.
(c) An external ground supply socket is accessible via the
radio bay door and is for the use when a ground battery is
necessary for servicing purposes.
(d) The table opposite lists the various electrical warning
lights and indicators in the cockpit. Failure in any
circuit (except radar ranging) incorporating a "dolls-
eye" magnetic indicator is shown by the indicator
showing white.
------------------------------------------------------------------------
A.L.1 (e) Emergency battery
Para. 18 (e)
Page 20 An emergency battery is provided to supply the emergency lamps,
the Manual emergency selector circuit (Mod. 502) and, when Mod.
488 is embodied the turn and slip indicator. If fully charged the
battery will provide between 7 and 20 hours' continuous use, depend-
ing on the load imposed on it.
(f) Instrument supply
(i) The turn and slip indicator is operated by d.c. whenever electrical
supply is available. If electrical supply is lacking the word OFF
appears in a window in the face of the instrument. When Mod.
488 is embodied the turn and slip indicator may be operated by
the emergency battery after setting on the switch below the
instrument.
(ii) A.C. for the Mk. 4F compass, artificial horizon, oil pressure
gauge and GGS radar ranging is supplied by two inverters. No. 1
inverter normally supplies the flight instruments and No. 2
inverter normally supplies the radar ranging. The engine starter
master switch controls the circuit to No. 2 inverter. No. 1 inverter
is brought into circuit when the undercarriage is not locked
down. During taxying and take-off the a.c. supply is from No. 2
inverter.
The RADAR TEST switch (8) may be used to test the inverters
before flight (see para. 61).
(iii)If No. 1 inverter fails in flight, automatic changeover occurs,
and No. 2 inverter then supplies the flight instruments, the load
to the radar ranging equipment, if in use, being shed.
(iv) Located on top of the a.c. junction box at the aft end of the
starboard shelf, are two circuit breakers (one for each inverter
supply), a magnetic indicator (which gives indication of inverter
changeover) and a STANDBY TESTING/NORMAL FLIGHT
switch (for servicing purposes only). This latter switch should
always be set to NORMAL FLIGHT (inboard). In flight none
of these is visible or accessible.
20
------------------------------------------------------------------------
|