INSTALLATION
6
December 2016 / W-SQ20 / EN
2.3
INSTRUCTIONS FOR OPTIMUM SOUND
AND VIBRATION INSULATION
Position the generating set as low as possible in the
vehicle. The generating set is already secured to the base
frame by means of flexible engine mountings. The base
frame is mounted to the chassis of the vehicle on a second
set of rubber mountings that is included in the delivery.
Use the included mounting template to determine the
mounting spots.
When it is possible to mount the unit directly on the
chassis of the vehicle this has advantages in preventing
vibrations by resonance.
2.3.1
Further recommendations
Whisper generating sets are standard equipped with a
sound cover. This sound cover has been designed to give
effective sound insulation. For optimum sound and
vibration dampening, the following factors should be
considered.
1
Most important is the structure on which the generator
is placed to be stiff. Directly below the rubber
mountings the structure should be supported vertically
to the chassis of the vehicle.
2
In larger vehicles a separate and insulated space for
the generator will help to damp the noise even further.
3
Avoid mounting the generating set in close proximity
to thin walls or floors that may cause resonance.
4
Sound dampening is extremely poor if the generating
set is mounted on a light weight flimsy surface such
as plywood which will only amplify vibrations. If
mounting on a thinner surface cannot be avoided, this
should be reinforced with at least stiffening struts or
ribbing. If possible, holes should be drilled or cut
through the surface to help reduce the resonance.
Covering the surrounding walls and floors with a
heavy coating plus foam will certainly improve the
situation.
5
Never connect the base of the generating set directly
to walls or tanks.
2.4
VENTILATION
2.4.1
General
The generating set normally draws air from the engine
compartment.
Engine
compartments
with
natural
ventilation must have vent openings of adequate size and
location to enable the generating set to operate without
overheating. To allow an ample supply of air within the
temperature limits of the generating set an opening of at
least a half square meter (0,5 m
2
) is required.
A "sealed" engine compartment must have a good
extraction ventilator to maintain reasonable ambient
temperatures. High temperature of intake air reduces
engine performance and increases engine coolant
temperatures. Air temperatures above 25°C reduce the
engine power by 2% for each 5°C of rise. To minimise
these effects, the engine room temperature must not be
more than 15ºC above the outside ambient air
temperature.
Apply a combination of ventilators, blowers and air intake
ducting to meet the temperature limit. The air inlet ducts
should run to the bottom of the engine compartment to
clear fumes from the bilge and to circulate fresh air. Air
outlets should be at the top of the engine compartment to
remove the hottest air. An engine compartment blower
should be used as an extraction ventilator to remove air
from the engine room.
In cases where it is impossible to meet the above
mentioned temperature limit by using engine compartment
ventilation, connections are to be made for an air inlet
directly to the generator enclosure. With these connections
the generating set can be directly connected to an air duct.
Air inlets should be louvered, where appropriate, to protect
the engine room and to protect the generating set from
rain and water spray.
Figure 5: Mounting of the Whisper generating set.
X = wrong, V = OK
