Orientation; Identification; Canopy; Engine, Generator, And Controls - Hobart Jet-Ex 5D Operation And Maintenance Manual

OM-2094 / Operation and Maintenance Manual
Jet-Ex 5D / Series 500285 / Generator Set

Orientation

3.
The radiator end of the Jet-Ex 5D is the front. Right and left are determined by standing at the rear of
the unit, facing it. The control panel is located at the rear.

Identification

4.
The Jet-Ex 5D unit is identified by Specification numbers as described in paragraph 1. There may be
any number of Generator sets with the same Specification number. Individual machines are identified
by a Serial number, assigned to one machine only.
Each generator set has an Identification plate attached inside the control box. This nameplate lists the
machines Model No. (Jet-Ex 5D), Specification No., Serial No., and electrical rating.
If any of the options described in paragraph 2.b. are included, they will be listed by name and part
number on a separate option nameplate located next to the Identification plate.

Canopy

5.
The standard canopy is a sheet metal enclosure which protects the engine, generator, and electrical
controls. It has four hinged doors to provide access for service and maintenance. A bolted on panel at
the rear (below the control box) provide access to the rectifier assembly. A Lexan window is mounted in
front of the control panel to allow observation of the instruments while protecting them from the
weather.

Engine, Generator, and Controls

6.
a. General
The engine (7, Figure 2) and generator (5) are mounted on a welded steel frame (6). A fuel tank
support (1) located at the rear of the unit supports the fuel tank (2) and provides a mounting frame
for the load contactor (10) and output terminals. The radiator (7, Figure 4) is mounted to the front
canopy and frame.
b. Engine

(1) General

The engine used in the Jet-Ex 5D generator set is a Cummins Model 4BT3.9 four-cylinder,
four-stroke, direct injection diesel engine. It has a 238 cubic inch (3.9 liter) cylinder displacement
and a 17.5:1 compression ratio. Engine firing order is 1-3-4-2.
A spring-loaded relief valve in the oil pump limits maximum pressure in the system. A full-flow oil
filter (3, Figure 3) cleans the oil before it enters the oil distributing system. A low oil pressure
switch is mounted on the engine block as a protective device. The fuel valve solenoid circuit is
wired through the contacts of this switch, which closes at 20 PSI (138 kPa). This prevents the
engine from continuing operation if oil pressure will not build up, and also shuts down the engine
if oil pressure drops radically during operation.
See the engine operator's manual for additional engine specifications.
The generator and engine are mounted on a welded steel skid, and are enclosed by a sheet
metal canopy that bolts to the skid. Access to engine serviceable components (oil filter, air
cleaner, etc.) is through the doors on each side of the machine.
The rear panel is removable and permits access to the rectifier assembly.
Chapter 1-1
Page 4
November 1, 2000
Revised 07/01