Description/Operation; Special Features; Section 1. Description; General - Hobart Jet-Ex 5D Operation And Maintenance Manual

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

Section 1. Description

General

1.
The Jet-Ex 5D units (Figure 1) covered in this manual are diesel engine driven, self-contained
generator sets manufactured by Hobart Brothers Company, Ground Power Division, Troy, Ohio U.S.A.
A basic unit is identified by a Series Number - 500285 - plus a dash number which defines a specific
configuration. The Series Number, plus the dash number, make up the Specification Number.
Specification No. 500285-001 covers a trailer mounted unit rated at 28.5 Volts DC output. It is equipped
with a sheet metal canopy and four hinged engine compartment doors. Various options are available
for use with the basic unit. A few of these options are listed in paragraph 2.B below, but the complete
list of options are located in Appendix A.
The basic generator set is designed to generate and deliver 28.5 Volts DC power to an aircraft when its
on-board generators are shut down. In addition to providing continuous, regulated power to the aircraft,
the unit is also designed for starting any fixed-wing aircraft or helicopter which is equipped with an
external 28.5 Volts DC power receptacle.

Special Features

2.
a. Standard
The "Soft-Start" current limiting feature, recommended by most aircraft engine manufacturers,
provides the operator with controls to limit the inrush current to the aircraft engine's starter. When
the operator presets this control, the generator will provide constant voltage to the preset current
value. The more current is increased beyond the preset current value, the voltage will decrease to a
minimum of 14 volts DC, after which the voltage will remain constant as more current may be
delivered beyond the preset current value. Limiting inrush current is recommended by most engine
manufacturers to protect the aircraft engine's starter shear section. The current limiting control is
continuously adjustable from 300 amperes, which is recommended for helicopter and small turbine
starting, to 2000 amperes, required for starting larger aircraft engines when the control is turned
fully clockwise.
b. Options (See Appendix A for complete list)
Chapters 1-5 of this manual describes a basic "no options" generator set. Appendix A lists the
options available for this unit. Below are the mounting configurations.
November 1, 2000
Revised 07/01
Chapter 1. Description/Operation
Part Number
500285-001
500285-002
Mounting Configuration
Trailer Mounted with Cable
Trays
Stationary Mounted with
Cable Hangers
Chapter 1-1
Page 1