10 Bryant
2.6 TOTAL CIRCUIT ISOLATIONMETHOD
When a generator capable of powering all electrical
loads in the circuit is to be installed, the “Total
Circuit Isolation Method” may be used. 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.
2.7 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 the 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)

2.8 GENERATOR AC NEUTRALCONNECTIO NS
Bryant 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.
Failure to connect the generator neutral prop-
erly will result in unbalanced line-to-neutral
voltages. Resulting high voltages will cause
equipment damage.
2.9 TRANSFER SWITCH SIGNAL CONNECTIO NS
It is necessary to connect the control wires between
the generator and the transfer switch.
Control system interconnections consist of N1, N2,
T1, T2 and leads 23 and 194. Control system inter-
connection leads must be run in a conduit that is sep-
arate from the AC power lead. Recommended wire
gauge sizes for this wiring depends on the length of
the wire, as recommended below:
2.10 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 certain that normal source voltage
at the transfer switch is correct and the system
is ready to be placed into operation. Ensure
that the 5A and 15A fuses in the control panel
are removed when connecting or disconnecting
battery cables.
!
DANGER
!
DANGER
Section 2 — Installation
Bryant Liquid-cooled 25 kW Generator
MAXIMUM WIRE LENGTH RECOMMENDED WIRE
SIZE
460 feet (140m) No.18 AWG.
461 to 730 feet (223m) No.16 AWG.
731 to 1,160 feet (354m) No.14 AWG.
1,161 to 1,185 feet (565m) No.12 AWG.