Hobart 6921 Series Operation And Maintenance Manual page 28

OM-2040 / Operation and Maintenance Manual
90D20 / Generator Sets
NOTE: The service indicator is mounted on the engine control panel and connected to the air cleaner by
a rubber hose.
The indicator flag is visible only when the engine is running or when the flag is locked in
WARNING position.
(3) Exhaust System
The exhaust system consists of a special noise reducing muffler (3, Fig. 7) which is connected
by a rigid pipe (2) to a conventional exhaust manifold (1) . The tail pipe outlet directs exhaust out
the right side of trailer frame. Some specifications provide the muffler as shown below. Other
specifications provide an optional vertical mounting (not shown). Refer to the generator set
identification chart for muffler mounting information.
1. Exaust flange
2. Exhaust pipe
d. Generator
The 400-Hz generator is a brushless, revolving field, three-phase, alternating current type. The rotor
assembly is mounted by two, permanently lubricated, sealed ball bearings. The front bearing is
supported by the fan housing; the rear bearing is mounted in the exciter housing and both of these
are attached to the main generator stator housing. The front end of the rotor shaft extends forward
beyond the bearing and is attached to the engine flywheel by a hub and flexible disc coupling
assembly. The rear end of the rotor shaft extends rearward beyond the rear bearing into the exciter
stator housing. The exciter rotor is mounted on the shaft extention with a standard key and is
secured by a washer and 1/2" -13 thd., cap screw.
Chapter 1-1
Page 10
3. Muffler
4. Tailpipe
Noise Reduction Exhaust System
Figure 7
February 28/94
Revised