ELECTRICAL EQUIPMENT—Q.20
8.
Remove the shaft lock-nut, pinion stop, shim
and spring. Pull the pinion forward about 1/4 in
(6,35 mm).
9.
Apply a spring load to the drive end of the shaft.
The spring at the commutator end must start to
compress between 13—19 lbf (5,9 to 8,6 kgf),
reading to 19—25 lbf (8,611,34 kgf), after 1/16 in
(1,6 mm) movement.
10.
Replace shaft nuts, shim and spring.
PERFORMANCE TESTS
1.
Brushes to be bedded over at least 75% of their
area.
2.
Fit the starter to a special flywheel rig and
connect the power supply.
3.
With a supply of 10 volts only, check that the
starter fully engages with the flywheel.
4.
With a 12 volts supply circuit, complete five
operations
under
each
of
the
following
conditions, on a locked flywheel.
(a)
Distance between flywheel and pinion set
at 0.068 in (1,73 mm).
(b)
Distance between flywheel and pinion set
at 0.196 in (4.98 mm).
PERFORMANCE FIGURES
The figures obtained must be within the following limits.
1.
Typical Lock Torque: 36.5 lbf ft (5 kgf m) with
950-1050 A at 6.0 V.
2.
Typical Torque at 1250 -1300 rev/min: 12 lbf ft
(1,7 kgf m) with 420 480 A at 9.5 V.
3.
Typical Light Running Current: 100-120 A at
7,000 rev/min.
INSULATION TEST
1.
Using a 500v megger, the following tests should
show an insulation resistance of not less than I
megohm.
2.
Lift earth brushes and check the main terminal
to earth.
3.
With earth brushes still raised, check the
positive brush to earth.
Insulated Return Electrical System
With this system, the thermostart starting aid is
insulated from the induction manifold by an insulated
"BLOCK" bush. When a thermostart unit or insulating
bush is replaced, care must be taken not to exceed the
torque figure quoted on Page B.1. Overtightening of
these parts can crack the insulating bush and could
cause hard starting and an electrical short.
