ELECTRICAL EQUIPMENT—Q.62.Check the connections on the commutator endbracket. The larger connector carries the maindynamo output, the smaller connector the fieldcurrent.3.Switch off all lights and accessories, take off thecables from the terminals of the dynamo andconnect the two terminals with a short length ofwire.4.Start the engine and set to run at normal idlingspeed.5.Clip the negative lead of a moving coil typevoltmeter, calibrated 0 - 20 volts, to one dynamoterminal and the positive lead to a good earthingpoint on the yoke.6.Gradually increase the engine speed, when thevoltmeter reading should rise rapidly and withoutfluctuation. Do not allow the volt meter readingto reach 20 volts, and do not race the engine inan attempt to increase the voltage. It issufficient to run the dynamo up to a speed of1,000 rev/min. If the voltage does not riserapidly and without fluctuation the unit must bedismantled for internal examination, see Para4(b). Excessive sparking at the commutator inthe above test indicates a defective armaturewhich should be replaced.(b)To Dismantle1.Take off the driving pulley.2.Unscrew and withdraw the two through bolts.3.Withdraw the commutator end bracket from theyoke.4.Lift the driving end bracket and armatureassembly from the yoke. Take care not to losethe fibre thrust washer from the commutator endof the shaft.5.The driving end bracket, which on removal fromthe yoke has withdrawn with it the armature andarmature shaft ball bearing, need not beseparated from the shaft unless the bearing issuspected and requires examination, or thearmature is to be replaced; in this event thearmature should be removed from the endbracket by means of a hand press, having firstremoved the shaft key.(c)Brush Gear (Checking with yoke removed)1.Lift the brushes up into the brush boxes andsecure them in that position by positioning thebrush springs at the sides of the brushes.Fig. Q.2.Dynamo Dismantled.
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
