Section 2 — Installation
Guardian
EMERGENCY CIRCUIT
ISOLATION METHOD
This prevents overloading the generator by keeping elec- trical loads below the wattage/amperage capacity of the generator. If the generator is powering only critical loads, within the wattage/amperage capacity, during util- ity power outages, you might consider using the emer- gency circuit isolation method.
Critical electrical loads are grouped together and wired into a separate “Emergency Distribution Panel.” Load circuits powered by that panel are within the wattage/amperage capacity of the generator set. When this method is used, it is difficult to overload the gener- ator. The transfer switch must meet the following requirements:
•It must have an ampere rating equal to the total amperage rating of the emergency distribution panel circuit.
•Have it installed between the building’s main distribu- tion panel and the emergency distribution panel.
TOTAL CIRCUIT ISOLATION METHOD
When a generator capable of powering all electrical loads in the circuit is to be installed, you may use the “Total Circuit Isolation Method.” It is possible for the generator to be overloaded when this isolation method is employed. The following apply to the transfer switch in this type of system.
•Ampere rating of the transfer switch must equal the ampere rating of the normal incoming utility service.
•The transfer switch is installed between the utility service entrance and the building distribution panel.
GROUNDING THE GENERATOR
The National Electrical Code requires the frame and external electrically conductive parts of this equipment to be properly connected to an approved earth ground and/or grounding rods. For that purpose, a GROUND LUG (Figure 2.2) is provided on the generator mounting base. Consult a qualified electrician for grounding requirements in your area. Grounding procedures must meet local regulations.
Figure 2.2 – Generator Grounding Lug (typical)
GENERATOR AC
NEUTRAL CONNECTIONS
Generac uses an UNGROUNDED AC neutral. Grounding is recommended only at the main service entrance. If the neutral wire is grounded and one of the phase loads becomes grounded, the excessive current opens the load circuit breaker or collapses the generator field. The actu- al result depends on the electrical characteristics of the particular installed generator.
TRANSFER SWITCH START
SIGNAL CONNECTIONS
If your generator is to be installed with an automatic transfer switch, such as a Generac
Connect the
BATTERY INSTALLATION
Do not connect the ground wire to any pipe that carries a flammable or explosive substance – FIRE or an EXPLOSION may result.
Proper grounding helps protect personnel against electri- cal shock in the event of a ground fault condition in the generator or in connected electrical devices. In addition, grounding helps dissipate static electricity that often builds up in ungrounded devices.
Standby generators installed with automatic trans- fer switches will crank and start automatically when normal (utility) source voltage is removed or is below an acceptable preset level. To prevent such automatic
Storage batteries give off explosive hydrogen gas. This gas can form an explosive mixture around the battery for several hours after charging. The slightest spark can ignite the gas and cause
10 Generac® Power Systems, Inc.
