General Information
Automatic Transfer Switch Owner’s Manual
5
Section 2: General Information
Introduction
Thank you for purchasing a Generac transfer switch. This
manual has been prepared especially for the purpose of
familiarizing personnel with the design, application,
installation, operation and servicing of the applicable
equipment. Read this manual carefully and comply with
all instructions. This will help to prevent accidents or
damage to equipment that might otherwise be caused by
carelessness, incorrect application, or improper
procedures.
Every effort has been expended to make sure that the
contents of this manual are both accurate and current.
The manufacturer, however, reserves the right to change,
alter or otherwise improve the product or manual at any
time without prior notice.
Unpacking
Carefully unpack the transfer switch. Inspect closely for
any damage that might have occurred during shipment.
The purchaser must file with the carrier any claims for
loss or damage incurred while in transit.
Check that all packing material is completely removed
from the switch prior to installation.
Equipment Description
The automatic transfer switch is used for transferring
electrical load from a UTILITY (NORMAL) power source
to a GENERATOR (STANDBY) power source. Such a
transfer of electrical loads occurs automatically when the
UTILITY power source has failed or is substantially
reduced and the GENERATOR source voltage and
frequency have reached an acceptable level. The
transfer switch prevents electrical feedback between two
different power sources (such as the UTILITY and
GENERATOR sources) and, for that reason, codes
require it in all standby electric system installations.
The transfer switch consists of a transfer mechanism,
utility service disconnect circuit breaker (if equipped), a
control relay, fuses, terminal strip, and fuse holder for
connection of sensing wires.
This transfer switch is suitable for use as service
equipment.
Transfer Switch Mechanism
These switches (
) are used with a three-phase
system when the three-phase NEUTRAL line is to be
connected to a neutral lug and is not to be switched.
Solderless, screw-type terminal lugs are standard.
The conductor size range is as follows:
This transfer switch is suitable for control of motors,
electric discharge lamps, tungsten filament and electric
heating equipment where the sum of motor full load
ampere ratings and the ampere ratings of other loads do
not exceed the ampere rating of the switch and the
tungsten load does not exceed 30 percent of the switch
rating.
This UL listed transfer switch is for use in optional
standby systems only (NEC article 702).
The 100A transfer switch is suitable for use on a circuit
capable of 14,000 rms symmetrical amperes, 480 VAC
maximum. The 200A transfer switch is suitable for use on
a circuit capable of 18,000 rms symmetrical amperes,
480 VAC maximum
.
Figure 2-1. Typical Single-Phase ATS
Transfer Mechanism
Switch
Rating
Wire Size
Torque
100A
#6–2/0 AWG
2/0–#3: 50 in-lb (5.6 Nm)
#4–6: 45 in-lb (5.1 Nm)
#8: 40 in-lb (4.5 Nm)
#10–#14: 35 in-lb (4.0 Nm)
200A
#4-400 MCM
275 in-lb (31.1 Nm)
A
Utility Lugs (N1, N2)
B
Generator Lugs (E1, E2)
C
Load Lugs (T1, T2)
000218
A
B
C
