Starting battery, 12 vdc battery system – Gillette Generators SPMD-2500 THRU SPMD-4000 User Manual
A) Engine driven blower fan.
B) Circulating coolant pump
C) Cooling radiator.
The blower fan pulls cooling air across the radiator
coils. The coolant pump circulates coolant through
the engine until it reaches operating temperature.
The engine thermostat open and allows coolant to
circulate into the radiator core. Thermostat can also
close, restricting the coolant flow, as necessary to
prevent over cooling. The engine fan blows air, from
the engine side, through the fins of the radiator.
When a generator set is installed inside a building
room, the radiator air discharge should be ducted
outside the building, into the atmosphere. A typical
installation is shown on page 14, Figure 5.
Install a set of louvers, 1½ times the size of engine
radiator perimeter. Galvanized metal duct must fit
tightly around louver perimeter and taper down to
be the same size as radiator perimeter, and end at
least 24”-30” from radiator. The connection from
engine radiator to duct work (12” space) should be
heavy canvas, silicone material, or other such
flexible material, to prevent noise and vibration
transmission. Sheet metal duct work should be self
supporting, firmly attached to the hot air discharge
The cool air inlet opening, should be a second set of
louvers that is (2) times the size of radiator perimeter.
Over-sizing both air inlet and air outlet, allows for
fine screens across the entire louver area to keep
birds or flying insects, from entering generator
The ideal assembly is to install motorized louvers, so
that when generator is started, the louver motors are
energized by generator power, and become fully
open. Like wise, when generator shuts down,
louvers automatically close.
Rain hoods should be installed over top of each
louver, mounted on outside wall, so that rain won’t
enter into open louvers.
TESTING THE VENTILATION SYSTEM
FOR MAXIMUM PROTECTION
Place a thermometer as close as possible to the cool
air input (engine cooling fan) of the generator set
blower housing. Don’t allow thermometer to touch
any metal surface. Place a second thermometer
outside the building in the hot air discharge, at point
of louvers. Be sure not to allow this thermometer to
be in direct sunlight or any other heat sources. Run
the generator at maximum load for about 1 hour. The
thermometers, should be no more than 20º F.
All generator models have a fixed position for
installer furnished, 12 or 24 VDC starting battery. A
corrosion free battery tray is furnished with woven
hold down strap. Positive and Negative battery
cables are installed and ready for connection to
installed battery. While installing the battery, notice
the Positive battery cable is tightly secured, so that it
can’t move beyond normal distance from Positive
battery post. DO NOT REMOVE THIS CABLE
RESTRAINT. This is a requirement of UL-2200 and
removal of this cable restraint will void UL
Certification. Also, battery connection boots for both
Positive and Negative cables are furnished and
again, required for UL Certification.
Starting batteries are usually sealed lead-acid type,
sized to engine manufacturers recommendation for a
cranking time. Recommended engine cranking
periods are specified in NFPA-110 and specifies
cranking cycles times. Battery sizes per generator
model number are on page 18.
Battery is charged by an engine driven, battery
charging alternator, while generator set is running.
These engine/generator systems have charge rates
of 30 to 50 amps or more, depending on size of
generator set, and can restore the charge from
battery, used in a normal cranking cycle within a
short period of time. When generator is in standby
position (not running), a very low charge rate from an
A-C powered battery charger can maintain battery at
All GILLETTE generators use a 6 or 10 amp, 12 or 24
VDC , 3 stage charger (bulk stage for full amp output
while battery voltage rises), absorption stage
(regulates battery voltage at constant voltage while
current flow to battery decreases), and float stage
(supplies charge current at the rate it will be
accepted by the battery).
12 VDC BATTERY SYSTEM
24 VDC BATTERY