Hobart Brothers 6910, Operation And Maintenance Manual With Illustrated Parts List

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The canopy is designed to reduce the operational noise level in the immediate area of the machine.
Doors and panels are covered on the inside with Fiberglass acoustic material to reduce reflected and con-
ducted noise, and to absorb noise. Noise producing vibration in most frequently used doors on the left
side is reduced by the use of two-point slam locks. Less frequently used doors on the right side are
equipped with screw-operated latch fasteners which are tightened after latching to reduce vibration. Insu-
lating strips around all doors also reduce noise. Metal strips are mounted horizontally across the front
grille to deflect engine fan exhaust air and noise upward.
Two large openings in the canopy top provide an entrance for cooling air and access to internal compo-
nents. A hood-type cover is mounted about two inches above each opening. The cover is flanged down-
ward and extends beyond the edges of the upwardly flanged opening to prevent entrance of blowing rain
while still allowing good air flow. Air enters the forward opening into the engine compartment and is dis-
charged through the radiator by the engine fan. Air enters the rear opening into the generator compart-
ment. It is then circulated over generator controls and drawn into the rear exciter and generator housings,
passing over all windings before being discharged by the generator fan.
7. Engine, Generator, and Controls Assembly
This assembly is the basic generator set without canopy. It includes all components required to generate
and regulate 400 Hz, 115/200 V, threephase power, and is operable when provided with fuel and 12 V DC
power. The engine-generator assembly is mounted on a welded steel frame. A superstructure, attached
to the main frame, provides mounting facilities for the canopy, control box, electrical equipment and con-
trols.
A. Basic Engine
This generator set is equipped with a 6-cylinder, in-line, turbo-charged John Deere Diesel engine.
See Figure 2 for general specifications, and see Engine Operator’s Handbook in Chapter 6 for more
detailed information.
B. Engine Manufacturer’s Equipment
As received from the engine manufacturer, the engine includes the following equipment which is de-
scribed in the John Deere Shop Manual
(Chapter 6)
.
(1) Fuel filter.
(2) Reverse-flow, engine cooling fan to blow air outward through the radiator.
C. Hobart Engine Equipment
The engine is modified at Hobart Brothers by the addition of the following equipment:
(1) Electric governor system
An electric governor kit is installed on the engine to replace a conventional, mechanical type. The
electric governor was selected for control of engine speed
(and generator output frequency) be-
cause it provides faster engine response to changes in load conditions. This fast response results
in very close frequency control. Refer to the Barber Coleman Handbook in Chapter 6 for a de-
tailed description. As briefly described below, the governor system consists of three main compo-
nents: the magnetic pickup, the control unit, and the actuator.
(a) Magnetic pickup
The magnetic pickup is a device for detecting the speed of the engine. It is mounted in the fly-
wheel housing directly over the ring gear. It produces an AC signal to the control unit when
the ferrous flywheel teeth pass through the magnetic field at the end of the pickup.
OM-2028
May 1/91 Revised 1-1
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