4
Generac
®
Power Systems, Inc.
1.1 UNPACKING/INSPECTION
After unpacking, carefully inspect the contents for dam-
age.
• This standby generator set has been factory installed
in an all-weather, metal enclosure that is intended
exclusively for outdoor installation.
If this generator is used to power electrical load
circuits normally powered by a utility power
source, code requires to install a transfer switch.
The transfer switch must effectively isolate the
electrical system from the utility distribution sys-
tem when the generator is operating (NEC 701).
Failure to isolate an electrical system by such
means will result in damage to the generator and
also may result in injury or death to utility power
workers due to backfeed of electrical energy.
If any loss or damage is noted at time of delivery, have
the person(s) making the delivery note all damage on
the freight bill or affix his or her signature under the
consignor's memo of loss or damage.
If there is loss or damage after delivery, separate the
damaged materials and contact the carrier for claim
procedures.
“Concealed damage” is understood to mean damage to
the contents of a package that is not in evidence at the
time of delivery, but is discovered later.
1.1.1 LIFTING THE GENERATOR
When lifting or hoisting equipment is used, be
careful not to touch overhead power lines.
The generator’s weight of more than 2,000
pounds requires proper tools and equipment, and
qualified personnel to be used in all phases of
handling and unpacking.
1.2 THE
GENERATOR
This liquid-cooled, Guardian generator set is designed
to supply electrical power to operate critical electrical
loads during utility power failure. Use this generator as
a source of electrical power for the operation of 120
and/or 240-volt, single-phase loads.
1.3 GENERATOR
AC
CONNECTION SYSTEMS
Figure 1.1 represents a single-phase, four-wire genera-
tor AC connection system. The stator assembly in this
system consists of a pair of stationary windings with
two leads brought out of each winding. Each single
winding can supply a 120-volt, 60-Hertz AC output.
When the two windings are connected in series, a 240-
volt, 60-Hertz AC output results. Typically, the two “hot”
leads in the circuit are Wires 11 and 44. The neutral
leads are the junction of Wires 22 and 33.
Figure 1.1 – Single-phase
Generator AC Connection System
1.4
PREPACKAGED TRANSFER SWITCH
The transfer switch shipped with this generator is rated
200 amps maximum at 120/240 volts AC single-phase.
The enclosure of the transfer switch is NEMA 3R. This
type of enclosure is intended for indoor or outdoor use.
Follow these rules:
• Install the transfer switch on a firm, sturdy support-
ing structure.
• To prevent switch distortion, level the switch if nec-
essary. This can be done by placing washers between
the switch enclosure and mounting surface.
• Never install the switch where any corrosive sub-
stance might drop onto the enclosure.
• Where practical, protect the switch against excessive
moisture, dust, dirt, lint, and construction grit.
Always prevent corrosive vapors from coming in con-
tact with enclosure.
1.5 AUTOMATIC SYSTEM OPERATION
When this generator, along with its transfer switch, has
been installed and interconnected, a circuit board in the
generator panel continuously monitors utility power
source voltage. Should that voltage drop below a preset
value, and remain at such a low state for a preset amount
of time, the generator cranks and starts. After the gener-
ator starts, the transfer switch transfers load circuits so
the generator can power them.
When utility source voltage has been restored, the
switch transfers back to the utility source voltage, and
the generator then shuts down after a brief cool-down
time.
Neutral Block
!
Section 1 — General Information
Guardian Liquid-cooled 40 kW Generator
