2.4.2 CONNECTING THE GENERATOR TO A BUILDING'S
ELECTRICAL SYSTEM
Connections for standby power to a building's electrical system
must be made by a qualified electrician and in strict compliance
with all national and local electrical codes and laws. The
connection must isolate the generator power from utility power or
other alternative power sources.
Because the generator equipment ground is bonded to the AC
neutral wires in the generator (see Figure 8), either a 3-pole
transfer switch or a 2 pole transfer switch with a switching
neutral kit is required to connect this generator to a building
load. In this application the generator becomes a separately
derived system (see NEC 250.20 (D)), and must be grounded
in accordance with the national or local electrical code
requirements.
Grounding the Generator in a Building Standby Application
The National Electrical Code requires that the
frame and external electrically conductive parts
of this generator be properly connected to an
approved earth ground.
Local electrical codes may also require proper grounding of the
unit (Figure 10). For that purpose, connecting a No. 10 AWG
(American Wire Gauge) stranded copper wire to the grounding lug
and to an earth-driven copper or brass grounding rod (electrode)
provides adequate protection against electrical shock. However,
local codes may vary widely. Consult with a local electrician for
grounding requirements in the area.
Proper grounding of the generator will help prevent electrical
shock in the event of a ground fault condition in the generator or in
connected electrical devices. Proper grounding also helps dissipate
static electricity, which often builds up in ungrounded devices.
Figure 10 - Grounding the Generator
NOTE:
2.5 DON'T OVERLOAD THE GENERATOR
Overloading a generator in excess of its rated wattage capacity
can result in damage to the generator and to connected electrical
devices. Observe the following to prevent overloading the unit:
• Add up the total wattage of all electrical devices to be connected
at one time. This total should NOT be greater than the
generator's wattage capacity.
• The rated wattage of lights can be taken from light bulbs. The
rated wattage of tools, appliances and motors can usually be
found on a data label or decal affixed to the device.
• If the appliance, tool or motor does not give wattage, multiply
volts times ampere rating to determine watts (volts x amps =
watts).
• Some electric motors, such as induction types, require about
three times more watts of power for starting than for running.
This surge of power lasts only a few seconds when starting
such motors. Make sure to allow for high starting wattage when
selecting electrical devices to connect to the generator:
1. Figure the watts needed to start the largest motor.
2. Add to that figure the running watts of all other connected
loads.
The Wattage Reference Guide is provided to assist in determining
how many items the generator can operate at one time.
All figures are approximate. See data label on appliance for
wattage requirements.
2.6 WATTAGE REFERENCE GUIDE
Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Running Watts
*Air Conditioner (12,000 Btu) . . . . . . . . . . . . . . . . . . . . . . . . . . 1700
*Air Conditioner (24,000 Btu) . . . . . . . . . . . . . . . . . . . . . . . . . . 3800
*Air Conditioner (40,000 Btu) . . . . . . . . . . . . . . . . . . . . . . . . . . 6000
Battery Charger (20 Amp). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500
Belt Sander (3") . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000
Chain Saw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200
Circular Saw (6-1/2") . . . . . . . . . . . . . . . . . . . . . . . . . . .800 to 1000
*Clothes Dryer (Electric) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5750
*Clothes Dryer (Gas) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700
*Clothes Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1150
Coffee Maker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1750
*Compressor (1 HP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000
*Compressor (3/4 HP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1800
*Compressor (1/2 HP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1400
Curling Iron. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700
*Dehumidifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650
Disc Sander (9") . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200
Edge Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500
Electric Blanket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400
Electric Nail Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200
Electric Range (per element) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1500
Electric Skillet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1250
*Freezer . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..700
*Furnace Fan (3/5 HP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 875
*Garage Door Opener . . . . . . . . . . . . . . . . . . . . . . . . . . . .500 to 750
Hair Dryer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200
Hand Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250 to 1100
Operation
NOTE:
9