Generac
®
Power Systems, Inc.
9
Section 2 – Installation
Generac Standby Generator Sets
2.4
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.
2.5
GROUNDING THE GENERATOR
The National Electrical Code requires the frame and
external electrically conductive parts of this equip-
ment 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 gener-
ator mounting base. Consult a qualified electrician
for grounding requirements in your area. Grounding
procedures must meet local regulations.
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
electrical shock in the event of a ground fault condi-
tion in the generator or in connected electrical
devices. In addition, grounding helps dissipate static
electricity that often builds up in ungrounded
devices.
Figure 2.2 – Generator Grounding Lug (typical)
2.6
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 actual result depends on the
electrical characteristics of the particular installed
generator.
2.7
TRANSFER SWITCH START SIGNAL
CONNECTIONS
If your generator is to be installed with an automatic
transfer switch, such as a Generac GTS-type switch,
it will be necessary to connect the two-wire start
control system.
Connect the two-wire start signal from the automatic
transfer switch to the automatic start connection,
which is located in the upper right hand corner of the
AC connection panel (see Figure 2.3). Match wires
178 and 183 in the transfer switch to 178 and 183 on
the terminal strip in the connection box. The con-
ductors for the two-wire start circuit must be in their
own conduit.
Figure 2.3 – Start Signal Connections
2.8
BATTERY INSTALLATION
Standby generators installed with automatic
transfer switches will crank and start automati-
cally when normal (utility) source voltage is
removed or is below an acceptable preset level.
To prevent such automatic start-up and possible
injury to personnel, do not connect battery
cables until you are certain that normal source
voltage at the transfer switch is correct and
you are ready to place the system into opera-
tion.
!
DANGER
AUTOMATIC START
CONNECTION
(WIRES 178 AND 183)
AC CONNECTION PANEL
DANGER
