Nexus Transfer Switches; Connection Diagrams - Generac Power Systems Stationary Emergency Generator Installation Manual

Operation
Figure 3.4 — Match Phase Rotation
While supporting the lugs, use a torque wrench to tighten the lugs
on the generator circuit breaker and the transfer switch. Torque
specifications are in the Transfer Switch Owner's Manual (Figure
3.5).
Consult the Technical Manual that comes with the transfer switch
for wiring diagrams and any product changes, modifications or
updates.
Figure 3.5 — Torque Lugs
3.5

NEXUS TRANSFER SWITCHES

Generators equipped with the Nexus Digital Controller will be
matched to a Nexus or RTS transfer switch.
N = Normal Utility Supply
E = Generator Connection Panel
T = Load Distribution Panel
When installing these switches, terminals 178 and 183 (2-wire
start) are not used.
18
3.6

CONNECTION DIAGRAMS

All wiring in the standby electric power system must be in strict
compliance with applicable codes, standards and regulations.
Such wiring must be properly supported, routed, and connected.
In addition, wiring must be properly sized to carry the maximum
load current to which is will be subjected.
The connections between the generator and transfer switch will
vary depending on the equipment ordered. In each case there are
two types of interconnections, load wiring and control wiring.
Make sure to turn OFF both the NORMAL

(UTILITY) and STANDBY (EMERGENCY) power
supplies before trying to connect power source
and load lines to the transfer switch. Supply
voltages are extremely high and dangerous.
Contact with such high voltage power supply
lines causes extremely hazardous, possibly
lethal, electrical shock.
Be sure to maintain proper electrical clearanc-

es between live electrical parts and grounded
metal. Allow at least one-half inch of clearance
circuits up to 400 amps.
Extremely high and potentially lethal supply

voltages are present at the transfer switch when
verifying phase rotation. This operation should
only be performed by a trained electrician.
3.6.1 NEXUS CONTROLLER TO A RTS/NEXUS SMART
SWITCH
The Nexus controller generator consists of an AUTO/OFF/ MANUAL
switch and a 2-line LCD display. See Figure 3.6 for an interconnec-
tion diagram. See "Control Wiring" for control wire sizing recom-
mendations.
Make sure to turn OFF the NORMAL (UTILITY)

power supply before trying to connect the Utility
1 and Utility 2 control wires. Supply voltages
are extremely high and dangerous. Contact with
such high voltage power supply lines causes
extremely hazardous, possibly lethal, electrical
shock.
Terminals 178 and 183 in the generator AC con-

nection box are not used in this application.
Connection of any wires to these terminals may
result in unwarrantable damage to the control
board.