
Owner’s Manual
100 Amp “V” Type
Transfer Switch
Models:
9227-2
4678-1
This manual should remain with the unit.

Generac®Power Systems, Inc.
Generac cannot possibly anticipate every possible cir
cumstance that might involve a hazard. The warnings in this manual, and on tags and decals
affixed to the unit are, therefore, not all-inclusive. If
you use a procedure, work method or operating technique Generac does not specifically recommend, you
must satisfy yourself that it is safe for you and others.
You also must make sure the procedure, work
method or operating technique that you choose does
not render the transfer switch unsafe.
Throughout this publication, and on tags and
decals affixed to the generator, DANGER, WARNING,
CAUTION and NOTE blocks are used to alert you to
special instruction about a particular operation that
may be hazardous if performed incorrectly or carelessly. Observe them carefully. Their definitions are
as follows:
After this heading, you can read instructions that,
if not strictly complied with, will result in personal
injury or property damage.
After this heading, you can read instructions that,
if not strictly complied with, may result in personal
injury or property damage.
After this heading, you can read instructions that, if
not strictly complied with, could result in damage to
equipment and/or property.
NOTE:
After this heading, you can read explanatory
statements that require special emphasis.
These safety warnings cannot eliminate the hazards
that they indicate. Common sense and strict compliance with the special instructions while performing the
service are essential to preventing accidents.
Four commonly used safety symbols accompany the
DANGER, WARNING and CAUTION blocks. The type
of information each indicates follows:
This symbol points out important safety information that, if not followed, could endanger personal
safety and/or property of you and others.
This symbol points out potential explosion hazard.
This symbol points out potential fire hazard.
This symbol points out potential electrical shock
hazard.
GENERAL HAZARDS
• Any AC generator that is used for backup power if
a NORMAL (utility) power source failure occurs,
must be isolated from the NORMAL (utility) power
source by means of an approved transfer switch.
Failure to properly isolate the NORMAL and
STANDBY power sources from each other may
result in injury or death to electric utility workers,
due to backfeed of electrical energy.
• Improper or unauthorized installation, operation,
service or repair of the equipment is extremely
dangerous and may result in death, serious personal injury, or damage to equipment and/or personal property.
• Extremely high and dangerous power voltages are
present inside an installed transfer switch. Any
contact with high voltage terminals, contacts or
wires will result in extremely hazardous, and possibly LETHAL, electric shock. DO NOT WORK ON
THE TRANSFER SWITCH UNTIL ALL POWER
VOLTAGE SUPPLIES TO THE SWITCH HAVE
BEEN POSITIVELY TURNED OFF.
• Competent, qualified personnel should install,
operate and service this equipment. Adhere strictly to local, state and national electrical and building codes. When using this equipment, comply
with regulations the National Electrical Code
(NEC) and Occupational Safety and Health
Administration (OSHA) have established.
• Never handle any kind of electrical device while
standing in water, while barefoot, or while hands
or feet are wet. DANGEROUS ELECTRICAL
SHOCK MAY RESULT.
Important Safety Instructions
Read the following information carefully before attempting to install, operate or service this
equipment. Also read the instructions and information on tags, decals, and labels that may
be affixed to the transfer switch. Replace any decal or label that is no longer legible.
DANGER! Connection of a generator to an electrical system normally supplied by an electric utility shall be by means of a double throw switch so as to isolate the electric system
from utility distribution system when the generator is operating (NEC 701). Failure to isolate electric system by these means results in damage to generator and may result in injury
or death to utility workers due to backfeed of electrical energy.
DANGER
!

Table of Contents
Generac®Power Systems, Inc. 1
Safety Rules ..................Inside Front Cover-1
Section 1 — General Information ................2
1.1 Introduction ................................................2
1.2 Equipment Description ................................2
1.3 Transfer Switch Ratings Decal ....................2
1.4 Transfer Switch Enclosure ..........................2
1.5 Safe Use Of Transfer Switch ........................2
Section 2 — Installation..................................3
2.1 Introduction to Installation ..........................3
2.2 Unpacking....................................................3
2.3 Mounting......................................................3
2.4 Connecting Power Source and Load Lines ..3
2.4.1 2-Pole Mechanism ........................3-4
2.5 Connecting Start Circuit Wires ....................4
Section 3 — Post Installation Start-Up
and Adjustments ..........................................5
3.1 Functional Tests & Adjustments ..................5
3.2 Manual Operation ........................................5
3.3 Transfer Switch Voltage Checks ..................6
3.4 Generator Tests Under Load ........................6
Section 4 – Notes ............................................7
Section 5 – Electrical Data ............................8
Section 6 – Exploded Views and
Parts Lists........................................................9
Section 7 – Warranty ....................Back Cover
• Because jewelry conducts electricity, wearing it
may cause dangerous electrical shock. Remove all
jewelry (such as rings, watches, bracelets, etc.)
before working on this equipment.
• If you must work on this equipment while standing
on metal or concrete, place insulative mats over a
dry wood platform. Work on this equipment only
while standing on such insulative mats.
• Never work on this equipment while physically or
mentally fatigued.
• Keep the transfer switch enclosure door closed and
bolted at all times. Only qualified personnel
should be permitted access to the switch interior.
• In case of an accident caused by electric shock,
immediately shut down the source of electrical
power. If this is not possible, attempt to free the
victim from the live conductor but AVOID DIRECT
CONTACT WITH THE VICTIM. Use a nonconducting implement, such as a rope or board, to free the
victim from the live conductor. If the victim is
unconscious, apply first aid and get immediate
medical help.
• When an automatic transfer switch is installed for
a standby generator set, the generator engine may
crank and start at any time without warning. To
avoid possible injury that might be caused by such
sudden start-ups, the system’s automatic start circuit must be disabled before working on or around
the generator or transfer switch. Always set the
Auto-Off-Manual switch to its OFF position before
working on the equipment. Then place a “DO NOT
OPERATE” tag on the transfer switch and on the
generator.

2 Generac®Power Systems, Inc.
Section 1 — General Information
Generac 100 Amp Transfer Switch
1.1 INTRODUCTION
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 the 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. Generac, however, reserves the right to change,
alter or otherwise improve the product at any time
without prior notice.
1.2 EQUIPMENT DESCRIPTION
The pre-packaged transfer switch is designed to use
with pre-packaged standby generator control panels.
It is used for transferring critical electrical loads
from a NORMAL (utility) power source. Such a transfer of loads occurs automatically when the NORMAL
power source fails or is subsequently reduced and
the STANDBY source voltage and frequency have
reached an acceptable level. The transfer switch prevents electrical feedback between two different power
sources (such as the NORMAL and STANDBY
sources) and, for that reason, codes require it in all
standby electric system installations.
Once the transfer is completed, the STANDBY power
source then powers electrical loads connected to the
transfer switch. When NORMAL source voltage
above an acceptable (preset) level has been restored,
voltage sensor action in the pre-packaged control
panel initiates re-transfer back to NORMAL power
source. After this re-transfer, the controller signals
to open the start circuit to the generator, which shuts
down the engine. The controller is then “armed” and
ready for the next drop in NORMAL source voltage.
NOTE: Keep in mind the pre-packaged transfer
switch is without any kind of electronic controls. It
receives signals solely from the controller contained
in the pre-packaged control panel.
1.3 TRANSFER SWITCH RATINGS
DECAL
Affixed to the transfer switch door is a RATINGS
DECAL. Use the transfer switch only within the specific limits shown on the RATINGS DECAL and on other
decals and labels that may be affixed to the switch.
This prevents damage to equipment and possible
injury to personnel, and provides long and trouble-free
life for the equipment.
When requesting information or ordering parts for this
equipment, make sure to include all information from
the RATINGS DECAL.
1.4 TRANSFER SWITCH ENCLOSURE
The standard switch enclosure is a National
Electrical Manufacturer’s Association (NEMA) 1 type.
NEMA 1 type enclosures primarily provide protection
against contact with the enclosed equipment and
against a limited amount of falling dirt.
1.5 SAFE USE OF TRANSFER SWITCH
Before installing, operating or servicing this equipment, read the SAFETY RULES (inside front cover)
carefully. Comply strictly with all SAFETY RULES to
prevent accidents and/or damage to the equipment.
Generac recommends you make a copy of the SAFETY RULES and post them near the transfer switch.
Also, be sure to read all instructions and information
you may find on tags, labels and decals affixed to the
equipment.
Two publications that outline the safe use of transfer
switches are the following:
• National Electrical Code
• UL 1008, STANDARD FOR SAFETY-AUTOMATIC
TRANSFER SWITCHES