FG Wilson Generating set Installation Manual

GENERATING SET

INSTALLATION

MANUAL

ii

FOREWORD

This installation manual will guide you to the factors to be considered in the
installation of your diesel generator system. It discusses location and mounting
of the generating set; size of room; ventilation and air flow; engine cooling water
supply or radiator location; exhaust outlet; fuel tank and fuel transfer system.

By following the suggestions in this installation manual, you will be able to plan
an economical, efficient generating set installation with operating characteristics
suitable to each particular application.

You can make you work easier by enlisting the aid of an FG Wilson Distributor
when planning your generating set installation. Getting his advice early may save
cost and avoid problems. He knows engines, electrical equipment, local laws and
insurance regulations. With his help, you can be sure your generating set
installation will fulfil your needs without unnecessary cost.

TABLE OF CONTENTS

PAGE

1. INSTALLATION FACTORS

2. MOVING THE GENERATING SET

3. GENERATING SET LOCATION

4. GENERATING SET MOUNTING

5. VENTILATION

6. ENGINE EXHAUST

7. EXHAUST SILENCING

8. SOUND ATTENUATION

9. ENGINE COOLING

10. FUEL SUPPLY

11. SELECTING FUELS FOR STANDBY DEPENDABILITY

12. TABLES AND FORMULAS FOR ENGINEERING STANDBY
GENERATING SETS:

1
1
1
2
3
6

9
10
10
13
18
19

Table 1 Length Equivalents
Table 2 Area Equivalents
Table 3 Mass Equivalents
Table 4 Volume and Capacity Equivalents
Table 5 Conversions for Units of Speed
Table 6 Conversions of Units of Power
Table 7 Conversions for Measurements of Water
Table 8 Barometric Pressures and Boiling Points of Water at Various Altitudes
Table 9 Conversions of Units of Flow
Table 10 Conversions of Units of Pressure and Head
Table 11 Approximate Weights of Various Liquids
Table 12 Electrical Formulae
Table 13 kVA/kW Amperage at Various Voltages

Conversions of Centigrade and Fahrenheit
Fuel Consumption Formulas
Electrical Motor Hor sepower
Piston Travel
Break Mean Effective Pressure

19
19
19
20
20
20
21
21
22
22
22
23
24

25
25
25
25
25

13. GLOSSARY OF TERMS 26

 Copyright 1997 by FG Wilson (Engineering) Ltd
All rights reserved. No part of the contents of this manual may be reproduced, photocopied or transmitted
in any form without the express prior written permission of FG Wilson (Engineering) Ltd.

1

1. INSTALLATION FACTORS

Once the size of the generating set and the required
associated control panel and switchgear have been
established, plans for installation can be prepared.
Proper attention to mechanical and electrical
engineering details will assure a satisfactory power
system installation.

Factors to be considered in the installation of a
generator are:

Access and maintenance location.
Floor loading.
Vibration transmitted to building and equipment.
Ventilation of room.
Engine exhaust piping and insulation.
Noise reduction.
Method of engine cooling.
Size and location of fuel tank.
Local, national or insurance regulations.
Smoke and emissions requirements.

2. MOVING THE GENERATING
SET

The generating set baseframe is specifically
designed for ease of moving the set. Improper
handling can seriously damage the generator and
components.

Using a forklift,the generating set can be lifted or
pushed/pulled by the baseframe. An optional "Oil
Field Skid" provides fork lift pockets if the set will
be regularly moved.

Never lift the generating set by attaching to the
engine or alternator lifting lugs!

For lifting the generating set, lift points are
provided on the baseframe. Shackles and chains of
suitable length and lifting capacity must be used
and a spreader bar is required to prevent damaging
the set. See figure 2.1. An optional "single point
lifting bale" is available if the generating set will be
regularly moved by lifting.

3. GENERATING SET
LOCATION

The set may be located in the basement or on
another floor of the building, on a balcony, in a
penthouse on the roof or even in a separate
building. Usually it is located in the basement for
economics and for convenience of operating
personnel. The generator room should be large
enough to provide adequate air circulation and
plenty of working space around the engine and
alternator.

If it is necessary to locate the generating set
outside the building, it can be furnished enclosed in
a housing and mounted on a skid or trailer. This
type of assembly is also useful, whether located
inside or outside the building, if the installation is
temporary. For outside installation the housing is
normally "weatherproof". This is necessary to
prevent water from entering the alternator
compartment if the generating set is to be exposed
to rain accompanied by high winds.

FIG 2.1. PROPER LIFTING ARRANGEMENT

2

4. GENERATING SET
MOUNTING

The generating set will be shipped assembled on a
rigid base that precisely aligns the alternator and
engine and needs merely to be set in place (on
vibration isolation pads for larger sets) and levelled.
See figure 4.1

4.1 Vibration Isolation

It is recommended that the generating set be
mounted on vibration isolation pads to prevent the
set from receiving or transmitting injurious or
objectionable vibrations. Rubber isolation pads are
used when small amounts of vibration transmission
is acceptable. Steel springs in combination with
rubber pads are used to combat both light and
heavy vibrations. On smaller generating sets, these
isolation pads should be located between the
coupled engine/alternator feet and the baseframe.
The baseframe is then securely attached to the
floor. On larger sets the coupled engine/alternator
should be rigidly connected to the baseframe with
vibration isolation between the baseframe and floor.
Other effects of engine vibration can be minimised
by providing flexible connections between the
engine and fuel lines, exhaust system, radiator air

discharge duct, conduit for control and power
cables and other externally connected support
systems.

4.2 Floor Loading

Floor loading depends on the total generating set
weight (including fuel and water) and the number
and size of isolator pads. With the baseframe
mounted directly on the floor, the floor loading is:

Floor Loading =

Total Gene rating Set Weight

Area of Skids

With vibration isolation between the baseframe and
the floor, if the load is equally distributed over all
isolators, the floor loading is:

Floor Loading =

Total Generating Set Weight

Pad Area x Number of Pads

Thus, floor loading can be reduced by increasing
the number of isolation pads.

If load is not equally distributed, the maximum floor
pressure occurs under the pad supporting the
greatest proportion of load (assuming all pads are
the same size):

Max Floor Pressure =

Load on Heaviest Loaded Pad

Pad Area

FIG 4.1 REDUCING VIBRATION TRANSMISSION

3

5. VENTILATION

Any internal combustion engine requires a liberal
supply of cool, clean air for combustion. If the air
entering the engine intake is too warm or too thin,
the engine may not produce its rated power.
Operation of the engine and alternator radiates heat
into the room and raises the temperature of the
room air. Therefore, ventilation of the generator
room is necessary to limit room temperature rise and
to make clean, cool intake air available to the
engine.

When the engine is cooled by a set mounted
radiator, the radiator fan must move large quantities
of air through the radiator core. There must be
enough temperature difference between the air and
the water in the radiator to cool the water
sufficiently before it re-circulates through the
engine. The air temperature at the radiator inlet
depends on the temperature rise of air flowing
through the room from the room inlet ventilator. By
drawing air into the room and expelling it outdoors
through a discharge duct, the radiator fan helps to
maintain room temperature in the desirable range.

In providing ventilation, the objective is to maintain
the room air at a comfortable temperature that is
cool enough for efficient operation and full
available power, but it should not be so cold in
winter that the room is uncomfortable or engine
starting is difficult. Though providing adequate
ventilation seldom poses serious problems, each
installation should be analysed by both the
distributor and the customer to make sure the
ventilation provisions are satisfactory.

5.1 Circulation

Good ventilation requires adequate flow into and
out of the room and free circulation within the room.
Thus, the room should be of sufficient size to allow
free circulation of air, so that temperatures are
equalised and there are no pockets of stagnant air.
See figure 5.1. The generating set should be
located so that the engine intake draws air from the
cooler part of the room. If there are two or more
generating sets, avoid locating them so that air
heated by the radiator of one set flows toward the
engine intake or radiator fan of an adjacent set. See
figure 5.2.

FIG 5.1 TYPICAL ARRANGEMENT FOR ADEQUATE AIR CIRCULATION AND VENTILATION

4

5.2 Ventilators

To bring in fresh air, there should be an inlet
ventilator opening to the outside or at least an
opening to another part of the building through
which the required amount of air can enter. In
smaller rooms, ducting may be used to bring air to
the room or directly to the engine's air intake. In
addition, an exit ventilator opening should be
located on the opposite outside wall to exhaust
warm air. See Figure 5.3.

Both the inlet and exit ventilators should have
louvres for weather protection. These may be fixed
but preferably should be movable in cold climates.
For automatic starting generating sets, if the
louvres are movable, they should be automatically
operated and should be programmed to open
immediately upon starting the engine.

FIG 5.2 TYPICAL ARRANGEMENT FOR PROPER VENTILATION WITH MULTIPLE GENERATING SETS

5

5.3 Inlet Ventilator Size

Before calculating the inlet ventilator size, it is
necessary to take into account the radiator cooling
air flow requirements and the fan static pressure
available when the generating set is operating at its
rated load. In standard room installations, the
radiated heat is already taken into account in the
radiator air flow.

For generator room installation with remote
radiators, the room cooling airflow is calculated
using the total heat radiation to the ambient air of
the engine and alternator and any part of the
exhaust system.

Engine and alternator cooling air requirements for
FG Wilson generating sets when operating at rated
power are shown on specification sheets. Exhaust
system radiation depends on the length of pipe
within the room, the type of insulation used and
whether the silencer is located within the room or
outside. It it usual to insulate the exhaust piping

and silencer so that heat radiation from this source
may be neglected in calculating air flow required for
room cooling.

After determining the required air flow into the
room, calculate the size of inlet ventilator opening
to be installed in the outside wall. The inlet
ventilator must be large enough so that the
negative flow restriction will not exceed a maximum
of
10 mm (0.4 in) H2O. Restriction values of air filters,
screens and louvres should be obtained from
manufacturers of these items.

5.4 Exit Ventilator Size

Where the engine and room are cooled by a set
mounted radiator, the exit ventilator must be large
enough to exhaust all of the air flowing through the
room, except the relatively small amount that enters
the engine intake.

FIG 5.3 INLET AND EXIT VENTILATORS

6

6. ENGINE EXHAUST

Engine exhaust must be directed to the outside
through a properly designed exhaust system that
does not create excessive back pressure on the
engine. A suitable exhaust silencer should be
connected into the exhaust piping. Exhaust system
components located within the engine room should
be insulated to reduce heat radiation. The outer
end of the pipe should be equipped with a rain cap
or cut at 60° to the horizontal to prevent rain or
snow from entering the exhaust system. If the
building is equipped with a smoke detection
system, the exhaust outlet should be positioned so
it cannot set off the smoke detection alarm.

6.1 Exhaust Piping

For both installation economy and operating
efficiency, engine location should make the exhaust
piping as short as possible with minimum bends
and restrictions. Usually the exhaust pipe extends
through an outside wall of the building and
continues up the outside of the wall to the roof.
There should be a sleeve in the wall opening to
absorb vibration and an expansion joint in the pipe
to compensate for lengthways thermal expansion or
contraction. See figure 6.1.

It is not normally recommended that the engine
exhaust share a flue with a furnace or other
equipment since there is danger that back pressure
caused by one will adversely affect operation of the
others. Such multiple use of a flue should be
attempted only if it is not detrimental to
performance of the engine or any other equipment
sharing the common flue.

The exhaust can be directed into a special stack that
also serves as the outlet for radiator discharge air
and may be sound-insulated. The radiator
discharge air enters below the exhaust gas inlet so
that the rising radiator air mixes with the exhaust
gas. See figures 6.2 and 6.3. The silencer may be
located within the stack or in the room with its tail
pipe extending through the stack and then outward.
Air guide vanes should be installed in the stack to
turn radiator discharge air flow upward and to
reduce radiator fan air flow restriction, or the sound
insulation lining may have a curved contour to
direct air flow upward. For a generating set
enclosed in a penthouse on the roof or in a separate
outdoor enclosure or trailer, the exhaust and
radiator discharges can flow together above the
enclosure without a stack. Sometimes for this
purpose the radiator is mounted horizontally and
the fan is driven by an electric motor to discharge
air vertically.

FIG 6.1 TYPICAL EXHAUST SYSTEM INSTALLATION

EXHAUST
SILENCER

WALL SLEEVE
AND EXPANSION
JOINT

SILENCER/PIPEWORK
SUPPORTS

RAIN CAP

7

6.2 Exhaust Pipe Flexible Section

A flexible connection between the manifold and the
exhaust piping system should be used to prevent
transmitting engine vibration to the piping and the
building, and to isolate the engine and piping from
forces due to thermal expansion, motion or weight
of piping. A well designed flex section will permit
operation with ± 13 mm (0.5 in) permanent
displacement in any direction of either end of the
section without damage. Not only must the section
have the flexibility to compensate for a nominal
amount of permanent mismatch between piping and
manifold, but it must also yield readily to
intermittent motion of the Generating Set on its
vibration isolators in response to load changes.
The flexible connector should be specified with the
Generating Set.

6.3 Exhaust Pipe Insulation

No exposed parts of the exhaust system should be
near wood or other inflammable material. Exhaust
piping inside the building (and the silencer if
mounted inside) should be covered with suitable
insulation materials to protect personnel and to
reduce room temperature. A sufficient layer of
suitable insulating material surrounding the piping

and silencer and retained by a stainless steel or
aluminium sheath may substantially reduce heat
radiation to the room from the exhaust system.

An additional benefit of the insulation is that it
provides sound attenuation to reduce noise in the
room.

6.4 Minimising Exhaust Flow
Restriction

Free flow of exhaust gases through the pipe is
essential to minimise exhaust back pressure.
Excessive exhaust back pressure seriously affects
engine horsepower output, durability and fuel
consumption. Restricting the discharge of gases
from the cylinder causes poor combustion and
higher operating temperatures. The major design
factors that may cause high back pressure are:

• Exhaust pipe diameter too small

• Exhaust pipe too long

• Too many sharp bends in exhaust system

• Exhaust silencer restriction too high

• At certain critical lengths, standing pressure

waves may cause high back pressure

FIG 6.2 HORIZONTALLY MOUNTED EXHAUST SILENCER FIG 6.3 RADIATOR AIR DISCHARGING INTO

WITH EXHAUST PIPE AND RADIATOR AIR SOUND-INSULATED STACK CONTAINING
UTILISING COMMON STACK EXHAUST SILENCER