Royal Enfield 350 BULLET 1949, Workshop Maintenance Manual

Page: 42 / 102

ROYAL ENFIELD WORKSHOP MANUAL
SECTION G2b
Lucas Dynamo Model E3LM
Used on all Models fitted with Magdyno
1. General
The dynamo is a shunt-wound two-pole
machine, arranged to work in conjunction with a
regulator unit to give an output which is
dependent on the state of charge of the battery
and the loading of the electrical equipment in
use. When the battery is in a low state of charge,
the dynamo gives a high output, whereas, if the
battery is fully charged, the dynamo gives only a
trickle charge to keep the battery in a good
condition without overcharging. In addition, an
increase of output is given to balance the current
taken by the lamps when in use. Model E3LM
(see Fig. 1) is designed to be the upper portion
of the "Magdyno" and has an output of 60 watts.
2 (a). Lubrication
No lubrication is necessary, as the ball
bearings are packed with H.M.P. grease, which
will last until the machine is taken down for a
general overhaul, when the bearings should be
repacked.
2 (b). Inspection of Commutator and Brush
Gear
About once every six months remove the
cover band for inspection of commutator and
brushes, see Subsection 4(a) (vi).
3. Test Data
Cutting-in speed (Dynamo Cold)
1,050 – 1,200 r.p.m. at 7 volts
Output test
8.5 amps at 1,850 – 2,000 r.p.m. at 7 volts*
Field resistance
2.8 ohms
Brush spring tension
16 – 20 oz.
*On resistance load of 0.82 ohm.
4 (a). Testing in Position to Locate Fault in
Charging Circuit
In the event of a fault in the charging circuit,
adopt the following procedure to locate the
cause of trouble.
(i) Check that the dynamo and regulator units
are connected correctly. The dynamo terminal
"D" should be connected to the regulator unit
terminal "D" and dynamo terminal "F" to
regulator terminal "F."
(ii) Remove the cables from the dynamo
terminals " D " and " F " and connect the two
terminals with a short length of wire.
Section G2b Page 1
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