Section 2 – Installation
QUIETPACT™ 75D Recreational Vehicle Generator
2.3COOLING AND VENTILATING AIR
It is absolutely essential that an adequate flow of air for cooling, ventilation, and engine combustion be supplied to the generator set. Without sufficient air- flow, the engine/generator quickly overheats. Such overheating can cause serious operating difficulties and also may cause fire and personal injury. The installer must make sure that sufficient air is avail- able to the generator for cooling, ventilating, and combustion. The installer also must provide a path for exhausting the cooling air to the exterior of a com- partment, if so equipped.
DANGER
Never use discharged cooling air for heating or permit such air to enter the vehicle interior. This air contains deadly carbon monoxide gas and other poisonous, flammable, or explosive gases.
◆2.3.2 COOLING AIR INLET OPENINGS
The minimum size of the air inlet opening, whether the generator is housed in a conventional compart- ment or not, is at least 150 square inches (975 cm2) (see Figure 2.8). This rule applies whether inlet air is brought in through an opening in the com- partment door, an opening in the vehicle skirt, through ductwork, or by any other means.
NOTE:
Screening, louvers, or expanded metal that cover air openings restrict airflow. Compensate for this by making the actual air opening proportionately larger. See Section 2.3.3.
Figure 2.8 – Air Inlet in Compartment Door
◆ 2.3.1 GENERATOR AIRFLOW
This unit uses an impellar fan located on the alterna- tor drive pulley to cool the alternator’s internal com- ponents. Air is drawn through the alternator and expelled radially behind the drive pulley. An engine- driven centrifugal blower draws in cooling air through air inlet openings, moves that air around the engine/generator and across the radiator, then dis- charges that air out the bottom (see Figure 2.7).
Figure 2.7 – Airflow Through Engine/Generator | When the unit is installed on a suspended mounting |
| |
| system, one of several different methods of supplying |
| airflow may be used as follows: |
| • Provide a door in the vehicle skirt having an air |
| inlet opening (Figure 2.9). |
Figure 2.9 – Suspended Mount: Inlet Door
• Use ductwork (Figure 2.10). The installer must be sure air is available to the sides of the generator for proper air intake.
• Provide an opening in the vehicle skirt and space around the generator for cooling airflow (Figure 2.11). Recommended clearance around all sides of the generator is at least two inches (50 mm).
26 Generac® Power Systems, Inc.