Scania Generator set en-GB 2 374 139. Operator’s manual - part 2
Transport and installation
Removing transport protection
Take care when removing the transport protec-
tion using a knife or scissors so as not to damage
the underlying paintwork or cable harness on the
machine.
Remove any wooden blocks positioned under the
generator set.
Design of the external exhaust sys-
tem
WARNING!
Exhaust gases contain carbon monoxide and ni-
trogen oxides, which are toxic. Ensure that all
exhaust gases are properly vented as inhalation
can be fatal.
WARNING!
Equip the external exhaust system with exhaust
guards or thermal insulation to minimise the risk
of burn injuries.
A generator set with canopy is supplied with an
operational exhaust system.
Make a note of the points in the following sec-
tion on open generator sets and where a genera-
tor set with a canopy is to be provided with an
external exhaust system.
16
Transport and installation
Positioning the silencer
L(m)
2.0
Position the silencer as close to the end of the ex-
1
haust system as possible. In order to obtain the
1.8
best noise reduction, there should only be a short
tailpipe after the silencer (0.8-1.5 m) as shown in
1.6
the chart. Read off the engine operating speed.
2
If the silencer cannot be positioned close to the
1.4
exhaust system outlet because of a lack of space,
it should be placed as close to the engine as pos-
1.2
sible. This location is, however, unfavourable in
3
silencing terms if the pipes beyond it are long. It
1.0
may be advisable to install another silencer near
to the outlet.
0.8
r pm
Note:
1200
1500
1800
2100
2400
Sharp exhaust pipe bends close to the outlet in-
1. DC09
crease the risk of hissing sounds.
2. DC13
3. DC16
Exhaust outlet
Design the exhaust system so that the exhaust
gases are not reflected against vertical walls,
since this results in increased noise level.
Position the exhaust outlet so that no exhaust
gases can be drawn into the engine intake. If ex-
haust gases are drawn into the intake, intake air
temperature increases rapidly. The exhaust gases
contain soot particles so there is also a risk of the
air filter becoming blocked.
WARNING!
Position the exhaust outlet so that exhaust gases
cannot penetrate areas occupied by people, e.g.
residential buildings.
17
Transport and installation
Example
If 2 silencers are used in the system, they should
be positioned in series at a distance of 2/3 of the
length of the tailpipe and with the silencer used
to dampen high-frequency noise furthest away
from the engine.
Since the pipes which form part of an exhaust
system also operate as silencers, it is important
that they are dimensioned correctly.
Note:
The exhaust back pressure increases with the
number of pipe bends and with increased pipe
length. This leads to higher fuel consumption
and loss of power.
IMPORTANT!
The installer is responsible for ensuring that the
exhaust system is well sealed during installation.
The installer is also responsible for ensuring that
the pipe and silencer suspension is designed in
such a way that system leaks cannot arise during
operation.
18
Transport and installation
Examples of long exhaust systems (i.e. longer
than 5 metres) with designs which aid sound re-
duction.
a
L
Examples of short exhaust systems with designs
a
L
which aid sound reduction.
a
L
L
L = Length of tailpipe, determined from graph.
a = 2/3 of L. Length a is less significant in ex-
a
haust systems with only one silencer.
The table can be used as reference when plan-
ning an exhaust system with industrial silencer.
Gen. set (kVA)
Expansion unit
Pipe diameter
Maximum pipe
Maximum number
(inches)
(inches)
length (m)
pipe bends
144-275
4
4
15
3
330-500
5
5
15
3
550-600
6
6
15
3
19
Transport and installation
Connection of exhaust system to engine
There should always be a flexible connection be-
tween the exhaust system and the engine which
absorbs the movement of the engine and changes
in length in the exhaust system due to tempera-
ture changes. A flexible connection can consist
of the Scania exhaust bellows.
The weight of the exhaust system must not load
the exhaust bellows or turbocharger. Therefore,
place a suspension point immediately after the
flexible connection.
If the exhaust pipes are very long or if the ex-
haust system has a relatively long horizontal part
between two vertical parts, several flexible con-
nections may be required in the system. There
must then be a fixed anchorage point on one side
of the vertical exhaust bellows and a suspension
which allows axial movement on the other side.
Exhaust back pressure
The back pressure in the exhaust system must not
exceed the maximum recommended exhaust
back pressure, including silencers. A higher ex-
haust back pressure leads to increased fuel con-
sumption and a loss of power.
The maximum recommended exhaust back pres-
sure is 100 mbar for all engines.
Always check the exhaust back pressure when
installation is complete. Perform the measure-
ment on a straight section of the system approx-
imately 1 metre downstream of the turbocharger.
20
Transport and installation
Insulating the exhaust system
Assess on a case-by-case basis whether the ex-
haust system requires thermal insulation.
If the engine intake air is taken from the engine
room, exhaust pipes should be insulated espe-
cially well to keep down the temperature in the
engine room.
Other reasons for insulating the exhaust system
are to prevent burn injuries to personnel, reduce
ventilation costs or reduce the risk of fire from
Insulating the exhaust system
the discharge of fluids, such as hydraulic oil. The
exhaust system may also require insulation if
there are lead throughs made of or near flamma-
ble material.
The insulation should withstand a temperature of
at least 700°C.
The outer shell of the insulation must be so well
sealed that fibres from the insulation cannot
come loose during vibration and block the air fil-
ter.
The insulation of long pipes affects the exhaust
back pressure. The diameter of the exhaust sys-
tem should therefore be increased if it is insulat-
ed. An insulated system can increase the noise
level at the outlet. This should also be considered
when determining the measurements.
IMPORTANT!
The insulation must be designed so that the flex-
ible part of the exhaust system is not restricted in
its movement. It must also be possible to inspect
the exhaust system without damaging the insula-
tion during dismantling.
21
Transport and installation
Protection against water ingress
The exhaust system must be designed to prevent
water ingress. If rain or condensation enters the
exhaust system, this causes corrosion damage. If
water reaches all the way into the engine, in the
worst cases this can lead to bent connecting rods
and the total destruction of the engine.
Long exhaust systems should be equipped with a
condensation separator. It should be located as
close to the engine as possible, but after the flex-
ible connection.
The occurrence of condensation is greater with a
vertical exhaust system since the exhaust gases
in a horizontal system carry away much of the
condensation.
Even with short exhaust pipes, it may be a good
idea to fit a condensation separator if there is any
risk of rain water entering.
Vertical exhaust outlets must be fitted with a de-
vice that prevents water ingress.
22
Transport and installation
Grounding the generator set
WARNING!
The generator set must be grounded in accord-
ance with national or local regulations. Ground-
ing regulations may vary from country to
country.
WARNING!
If necessary, shield power cables against me-
chanical damage using cable protectors.
WARNING!
Warn people of the risk of tripping when power
cables have been laid out.
REQUIREMENT!
At the very least, ground cables or ground strips
must have full load capacity and must comply
with the applicable regulations.
Ground screw
The generator set has a ground screw for safe
connection to ground. The ground screw is locat-
ed on one of the longitudinal frame members of
the base frame. Next to the ground screw is a
sticker with a ground symbol.
Ground screw (example)
23
Transport and installation
Connecting electrical consumers
WARNING!
Electrical consumers may only be connected by
trained and qualified personnel authorised to car-
ry out this work.
WARNING!
Electrical consumers may only be connected in
full compliance with national or local regula-
tions.
Busbars
The generator set has busbars for the connection
of electrical consumer cable harnesses. The bus-
bars are protected by a hatch which is screwed
into place.
Note:
The illustration shows a 3-pin circuit breaker in
the generator set, which is the standard specifica-
tion. A 4-pin circuit breaker is available as an op-
tion.
Busbars with the hatch removed (example)
24
Transport and installation
Power cables
WARNING!
If necessary, shield power cables against me-
chanical damage using cable protectors.
WARNING!
Warn people of the risk of tripping when power
cables have been laid out.
Depending on how the generator set is moving
on its vibration brackets, the electrical connec-
tion to the generator set should be made using
flexible power cables. This prevents vibrations
being transferred which may damage the genera-
tor or busbars.
The power cables must be appropriate for the
generator set output voltage and rated current.
Take the ambient temperature, installation meth-
od, cable length and bundling into account when
determining the size of the power cables.
When single core power cables are used, the
lead-in plates must be made of aluminium, brass
or a non-metallic material such as tufnol. An al-
ternative is to cut grooves between the electrical
cable lead-ins to prevent any currents circulating
in the lead-in plates.
Check the phase rotation in order to ensure that it
is compatible with the installation site.
25
Transport and installation
Load
When electrical distribution system is being
planned, it is important to ensure that a balanced
load is supplied to the generator set.
If the load on one phase is considerably greater
than that on the other phases, this can cause over-
heating in the generator windings or imbalance
in the output voltage from phase to phase.
Ensure that no single phase current exceeds the
rated current of the generator set.
When connecting to an existing distribution sys-
tem, it may be necessary to reorganise the distri-
bution system to ensure that these load factors
are fulfilled.
Power factor
Determine the power factor of the connected
load. Power factors of 0.8 lag (reactive) can
overload the generator. The generator set pro-
vides its kW class and runs satisfactorily from an
0.8 lag to a unit power factor (1.0).
26
Transport and installation
Actions prior to starting after
transport
Do the following prior to starting for the first
time after delivery:
• Fit fully-charged batteries (included in the
delivery).
• Check the engine oil level.
• Check the engine coolant level and the cool-
ant antifreeze or corrosion inhibitor.
• Fill the internal fuel tank.
• Bleed the fuel system.
Oil level and coolant level/antifreeze
Instructions for checking the oil level and cool-
ant level of the engine can be found in the Indus-
trial engine Operator’s manual.
Fuel system
Filling the internal fuel tank
Instructions for filling the internal fuel tank can
be found in the section Filling the internal fuel
tank.
Bleeding the fuel system
If the fuel tank has been empty, the fuel system
must be bled. See the Industrial engine Opera-
tor’s manual.
27
Generator set design
Generator set design
The generator set comprises the main parts as
shown in the figure below.
1
2
3
4
5
6
9
7
8
1. Silencer (hidden)
2. Added on engine cooling system
3. Batteries, 24 V electrical system
4. Engine
5. Basic frame with integrated fuel tank
6. Air cleaner
7. Generator
8. 24 V and 230 V central electric unit
9. Central electric unit for current consumers
Base frame
The generator set basic frame comprises 2 longi-
tudinal beams and an integrated fuel tank. A re-
tainer collects any spilt oils or fluids.
1
The longitudinal beams have four load securing
eyes used to secure the generator set during tran-
sit.
The longitudinal beams also contain holes for
2
e.g. fitting fork tunnels, for lifting using a loader
2
with lifting forks.
1. Load securing eye
The holes can also be used for attaching the gen-
2. Hole
erator set to the floor in a fixed installation.
28
Generator set design
Canopy
The canopy comprises an end plate section and a
combined centre and end plate section. The sec-
tions can be removed separately.
Scania Genset SG500
There are air intake grilles on both sides of one
of the end plate sections to supply the generator
set with air. There are air outlet grilles on the roof
of the opposite end plate section.
Air intake grille
Air outlet grille
Two hatches on each long side provide access to
the engine and generator for maintenance pur-
poses. One hatch on one of the end plates pro-
vides access to the instrument panel and to the
junction blocks to connect the current consumer
power cables.
Scania Genset SG500
The hatches are equipped with a stop device on
the bottom edge that limits the opening angle and
holds the hatch open.
All five hatches are lockable with one common
key.
The whole canopy, including the hatches, is pro-
Hatches
vided with sound-absorbing insulation.
3
2
1
On the roof of the canopy there is an outlet for
the exhaust pipe and two alternative hatches for
filling the engine cooling system with coolant.
If the generator set is equipped with a lifting de-
vice (option), there is also a lifting eye on the
roof.
1. Exhaust pipe
2. Cover for topping up cooling system
3. Lifting eye
29
Generator set design
Engine/generator set
An engine/generator unit is fixed to a number of
attachments in the basic frame.
Generator
The generator has no brushes and is equipped
with a 3-phase voltage regulator.
The generator can be equipped with a permanent
magnet (option).
The generator, which is single-bearing, is bolted
to the engine via a drive plate. When the genera-
tor starts to rotate a voltage is induced in the
magnetising section. The induced voltage is rec-
tified and conducted to the generator rotor. The
generator stator then generates an output voltage
to load, which is monitored by the voltage regu-
Generator
lator.
There are two makes of generator: Mecc Alte
and Stamford. Both makes have variants for dif-
ferent voltages. A plate on the generator states
the make and voltage of the generator concerned.
In principle, the generator is maintenance-free
for users.
Engine
The engine is a direct-injection, liquid-cooled,
four-stroke, turbocharged, single-speed diesel
engine.
The engine is described in the Industrial Engine
instruction manual.
To drain the engine oil some generator sets have
a hose that feeds from the oil sump drain valve to
an external drainage point in one of the longitu-
dinal beams.
External drain valve for engine oil
30
Generator set design
Fuel system
1
The generator set fuel tank is made of steel and
integrated into the basic frame. It has a capacity
between 800 l and 1,100 l.
The fuel filler point is located on one edge with
a fuel gauge adjacent to it.
2
1. Fuel gauge
2. Refuelling
2
1
A fuel filter with water separator is located be-
tween the fuel tank and engine. Refer also to the
Industrial Engine instruction manual.
Fuel filter
1. From fuel tank
2. To engine
31