Generac Power Systems ATC-300+ Operation And Maintenance Manual

O & M Manual for ATC-300+ 40-400A (480/600Vac)
ATC-300+ 3-Position Contactor Based Transfer Switch

Instruction Booklet

Description Page

Introduction . . . . . . . . . .

Receiving, Handling, and Storage
Equipment Description . . .
Installation and Wiring . . .

Operation . . . . . . . . . . . .

Testing and Problem Solving
Adjustments

Maintenance . . . . . . . . . .

Renewal Parts Guide
ATC-300+ Contactor Based ATS Quick Start Instructions . .26

Appendix A: Pickup / Dropout Tables . . . . . . . . . .

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. . . . . . .36

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IB01602078E For more information visit: www.generac.com

Instruction Booklet

Cat No: ATC3C3X30400WRU
Style No:

ASSEMBLED IN MEXICO
WITH U.S. COMPONENTS 30 - 43465

ITEM: 001

PIECE: 001

CS#: 123456

J050412234

Volts: 240

Poles: 3

Amps: 400

Phase: 3

Hertz: 60

Wire: 3/4

GO No: ABC0123

OF: 001

Page 2 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Section 1: Introduction

WARNING

READ AND UNDERSTAND THE INSTRUCTIONS CONTAINED HEREIN­AFTER BEFORE ATTEMPTING TO UNPACK, ASSEMBLE, OPERATE,
OR MAINTAIN THIS EQUIPMENT.

HAZARDOUS VOLTAGES ARE PRESENT INSIDE TRANSFER SWITCH

CLOSURES THAT CAN CAUSE DEATH OR SEVERE PERSONAL

EN
INJURY. FOLLOW PROPER INSTALLATION, OPERATION, AND MAIN­TENANCE PROCEDURES TO AVOID THESE VOLTAGES

TRANSFER SWITCH EQUIPMENT COVERED BY THIS INSTRUCTION
BOOK IS
PLATE RATINGS. OPERATION OUTSIDE OF TH
CAUSE THE EQUIPMENT TO FAIL RESULTING IN DEATH, SERIOUS
BODILY INJURY, AND/OR PROPERTY DAMAGE. ALL RESPONSIBLE
PERSONNEL SHOULD LOCATE THE DOOR MOUNTED EQUIPMENT
NAMEPLATE AND BE FAMILIAR WITH THE INFORMATION PROVIDED
ON THE NAMEPLATE. A TYPICAL EQUIPMENT NAMEPLATE IS
SHOWN IN FIGURE 1.

DESIGNED AND TESTED TO OPERATE WITHIN ITS NAME-

Figure 1. Typical Automatic Transfer Switch (ATS) Equipment
Nameplate.

All possible contingencies that may arise

during installation, oper­ation, or maintenance, and all details and va
ment do no purport to be covered by these instructions. If further
information is desired by the purchaser r

egarding a particular
installation, operation, or maintenance of particular equipment,
please contact an authorized Generac Sales Representative or the
installing contractor.

.

ESE RATINGS MAY

riations of this equip-

1.1 Preliminary Comments and Safety Precautions

This technical document is intended to cover most aspects asso­ciated with the installation, application, operation, and mainte­nance of the Automatic Transfer Controller (ATC-300+)
controlled c

ontactor based ATS with ratings from 40 through
400 amperes (A). It is provided as a guide for authorized and
qualified personnel only. Please refer to the specific WARNING
and CAUTION in Section 1.1.2 before proceeding. If further infor­mation is required by the purchaser regarding a particular installa­tion, application, or maintenance activity, plea

se contact an
authorized Generac sales representative or the installing contrac­tor.

1.1.1 Warranty and Liability Information

No warranties, expressed or implied, including warranties of fit­ness for a particular purpose of merchant

ability, or warranties
arising from course of dealing or usage of trade, are made regard­ing the information, recommendations and de

scriptions contained
herein. In no event will Generac be responsible to the purchaser
or user in contract, in tort (including negligence), strict liability or
otherwise for any special, indirect, incidental or consequential
damage or loss whatsoever, including but not limited to damage
or loss of use of equipment, plant or power system, cost of capi­tal, loss of power, additional expenses in the use

of existing
power facilities, or claims against the purchaser or user by its
customers resulting from the use of the information and descrip­tions contained herein.

1.1.2 Safety Precautions

All safety codes, safety standards, and/or regulations must be
strictly observed in the installation, operation, and maintenance
of this device.

WARNING

THE WARNINGS AND CAUTIONS INCLUDED AS PART OF THE PRO­CEDURAL STEPS IN THIS DOCUMENT ARE FOR PERSONAL SAFETY
AND PROTECT
OF A TYPICAL WARNING LABEL HEADING IS SHOWN ABOVE TO
FAMILIARIZE PERSONNEL WITH THE STYLE OF PRESENTATION.
THIS WILL HELP TO INSURE THAT PERSONNEL ARE ALERT TO
WARNINGS, WHICH APPEAR THROUGHOUT THE DOCUMENT. IN
ADDITION, WARNINGS AND CAUTIONS ARE ALL UPPER CASE AND
BOLDFACE.

ION OF EQUIPMENT FROM DAMAGE. AN EXAMPLE

For more information visit: www.generac.com IB01602078E

CAUTION

COMPLETELY READ AND UNDERSTAND THE MATERIAL PRESENTED
IN THIS DOCUMENT BEFORE ATTEMPTING INSTALLATION, OPERA­TION, OR APPLICATION OF THE EQUIPMENT. IN ADDITION, ONLY
QUALIFIED
WORK ASSOCIATED WITH THIS EQUIPMENT. ANY WIRING
INSTRUCTIONS PRESENTED IN THIS DOCUMENT MUST BE FOL­LOWED PRECISELY. FAILURE TO DO SO COULD CAUSE PERMANENT
EQUI

PERSONS SHOULD BE PERMITTED TO PERFORM ANY

PMENT DAMAGE.

40-400A (480/600Vac) ATC-300+ 3-Postion

Source 1

Source 2

Load

LOGIC

PANEL

VOLTAGE SELECTION AND
TRANSFORMER PANEL

POWER PANEL

Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 3

1.2 General Information

Transfer switches are used to protect critical electrical loads
against loss of power. The load’s Source 1 power source is
backed up by a Source 2 power source. A transfer switch is
connected to both the Source 1 and Source 2 power sources and
supplies the load with power from one of the two sources. In the
event that power is lost from Source 1, the transfer switch trans­fers the load to the Source 2 power source. This transfer is auto­matic. Once Source 1 power is restored, the load is
automatically trans
(Figure 2).

ferred back to the Source 1 power source

and the Source 2 power source fails while the Source 1 power
source is still unavailable, the ATS remains connected to the
Source 2 power source.

ATSs automatically perform the transfer function and include

e basic elements:

thre

1. A power contactor to connect and disconnect the load to
nd from either power source.

a

2. Solenoids to make the transfer of the main contacts from

source to source.

3. Intelligence/supervisory circuits

condition of the power sources and thus provide the intelli­gence necessary for the switch and related circuit operation.

to constantly monitor the

1.2.1 Design Configuration

The Generac contactor based ATS is a compact design that uses
a power contactor to transfer essential loads from one power
source to another (Figure 3 [400A]).

Figure 2. Typical Load Transfer Switch Schematic (Contactor
Type).

In ATS equipment, the switch’s intelligence system initiates the

fer when the Source 1 power fails, falls below, or rises

trans
above a preset voltage. If the Source 2 power source is a
standby generator, the ATS initiates generator startup and trans­fers to the Source 2 power source when sufficient generator

age is available. When Source 1 power is restored, the ATS

volt
automatically transfers back and initiates generator shutdown.
In the event the Source 1 power source fails and the Source 2
power source does not appear, the ATS remains connected to
the Source 1 power source until the Source 2 power source does
appear. Conversely, if connected to the Source 2 power source

Figure 3. Typical Power Panel for a 400A Model.

The Generac contactor based ATS was designed with easy
installation and simplified maint
els comprise the contactor based ATS design:

1. Power panel;

2. Voltage selection and transformer panel (if required); and

3. Microprocessor-based logic panel.

enance in mind. Three main pan-

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Instruction Booklet

AT C 3 C3 X 3 0400 W R U

1to2 3 4 5 6 7 8 9to

12 13 14 15

to

Page 4 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Table 1. Withstand Ratings.

UL 1008 WITHSTAND AND CLOSE-ON RATINGS (kA)

UL 1008 Ampere Rating 480 Volts 600 Volts

Any

Breaker

100 30,000 30,000 22,000 35,000

200 30,000 30,000 22,000 35,000

260 30,000 50,000 – –

320 30,000 50,000 – –

400 30,000 50,000 – –

1.3 ATS Catalog Number Identification

Transfer switch equipment catalog numbers provide a significant
amount of relevant information that pertains to a particular piece
of equipment. The Catalog Number Identification Table (Table 2)
provides the required interpretation information. An example is
offered here to initially simplify the process.

Example: C

atalog Number (circled numbers correspond to position

headings in Table 2).

Specific
Breaker

Any

Breaker

Specific
Breaker

Figure 4. Contactor Based ATS (400A).

Each panel is independently mounted with interconnecting wiring
terminated at the connector receptacles on the ATC-300+ Con­troller. Door or individual panel removal is achieved without dis­turbing critical connections by removing the connectors from the

eptacles and cutting the wire ties that secure the wires to the

rec
door.

Mounting the enclosure is simple using top and bottom mounting
flanges with elonga
ing holes, along with power panel positioning bolts and pre­tapped inse
tial enclosure installation. Refer to Section 4 for specific mount­ing and modification details.

rts, insure proper power panel mounting after the ini-

ted (teardrop) mounting holes. These mount-

The catalog number ATC3C3X30400WRU describes an ATS with
a 3-pole, 3 position Power Contactor mounted on a baseplate
within the enclosure. The intelligence represented by the logic
panel is ATC-300+ controller. The continuous current rating of
this equipment is 400A and applicable at 240 Vac, 60 Hz. The
transfer switch equipment is enclosed in a NEMA 3R enclosure
and is listed for UL applications.

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Instruction Booklet

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Table 2. Transfer Switch Catalog Number Explanation

POSITIONS 1 TO 2 POSITION 3 POSITION 4 POSITIONS 5 TO 6

BASIC DEVICE SWITCHING DEVICE CONTROL PANEL SWITCHING DEVICE

Automatic Transfer Switch AT Contactor C ATC-300+ Controller 3 3 Position Power Contactor C3

POSITION 7 POSITION 8 POSITIONS 9 TO 12 POSITION 13 POSITION 14 POSITION 15

SWITCHING DEVICE

ARRANGEMENT

Fixed Mount X Two (2) 40A – 0040 208 Vac/60 Hz B Type 1 S UL/CSA Listing U

150A – 0150 380 Vac/50 Hz H Open K

*For 225A to 400A, 600 Vac application, please refer to IB01602024E

NUMBER

OF POLES

Three (3) 80A – 0080 220 Vac/50 Hz G Type 12 J No Listing X

Four (4) 100A – 0100 240 Vac/60 Hz W Type 3R R

AMPERE

RATING

200A – 0200 415 Vac/50 Hz O

*225A – 0225 480 Vac/60 Hz X

*260A – 0260 600 Vac/60 Hz E

*400A – 0400

VOLTAGE/

FREQUENCY ENCLOSURE LISTING

Effective: September 2011 Page 5

1.4 Environmental Conditions

1.4.1 Operational Conditions

Normally, an ATS is applied indoors in an electrical equipment
room. In the appropriate enclosure, it can be used for outdoor
applications where the equipment is subject to falling rain, freez
ing temperatures, and no greater than 90% humidity (non-con­densing). The ambient temperature range for operation is
between -20 and 70°C (-4 to 158°F).

1.5 Glossary

With respect to their use within this document and as they relate
to transfer switch and controller operation, the following termi
nology is defined.

Available

A source is defined as “available” when it is within its undervolt­age/overvoltage/ underfrequency/overfrequency (if applicable)
setpoint ranges for the nominal voltage and frequency setting.

Connected

Connected is defined as when the input is shorted by an external
contact or connection.

Failed or Fails

A source is defined as “failed” when it is outside of the applica­ble voltage and frequency setpoint ranges for the nominal volt­age and frequency setting for a time exceeding 0.5 seconds
after the time delay emergency fail (TDEF) time delays expires.

Failsafe

Failsafe is a feature that prevents disconnection from the only
available power source and also forces a transfer or re-transfer
operation to the only available power source.

-

Re-Transfer

Re-transfer is defined as a change of the load connection from
the Source 2 to the Source 1.

Source 1

Source 1 is the primary source (normal source, normal power
source, or normal).

-

Source 2

Source 2 is the secondary source (emergency source, emer­gency power source, emergency, standby, or backup source).

Source 1: Failed or Fails

Source 1 is defined as “failed” when it is outside of its under­voltage/overvoltage/ underfrequency/overfrequency (if applica­ble) setpoint ranges for the nominal voltage and frequency
setting.

Source 2: Failed or Fails

Source 2 is defined as “failed” when it is outside of its under­voltage/overvoltage/ underfrequency/overfrequency (if applica­ble) setpoint ranges for the nominal voltage and frequency
setting for a time exceeding 0.5 seconds after the Time Delay
Emergency Fail (TDEF) time delay expires.

Transfer

Transfer is defined as a change of the load connection from the
Source 1 to the Source 2 power source.

Unconnected

Unconnected is defined as when the input is not shorted by an
external contact or connection.

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Instruction Booklet

Page 6 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Section 2: Receiving, Handling, and
Storage

2.1 Receiving

Every effort is made to ensure that the ATS equipment arrives at
its destination undamaged and ready for installation. Packing is
designed to protect internal components as well as the enclo
sure. Care should be exercised, however, to protect the equip­ment from impact at all times. Do not remove the protective
packaging until the equipment is ready for installation.

When the ATS equipment reaches its destination, the customer
should inspect the shipping container for any obvious signs of
rough handling and/or external damage that occurred during
transportation. Record any external and internal damage for
reporting to the transportation carrier and Generac, once a thor
ough inspection is complete. All claims should be as specific as
possible and include the catalog and General Order numbers.

A shipping label affixed to the shipping container includes a vari­ety of equipment and customer information, such as General
Order Number and catalog numbers. Make certain that this infor
mation matches other shipping paper information.

Each transfer switch is packed securely with appropriate ship­ping materials to prevent damage during shipment. Do not
remove or discard the packing material until the equipment is
ready for installation.

Once the top packaging is removed from the shipment, the
enclosure door can be opened. A plastic bag of documents will
be found in the enclosure, usually attached to the inside of the
enclosure. Important documents, such as test reports, wiring
diagrams, and appropriate instruction leaflets, are enclosed
within the bag and should be filed in a safe place.

-

2.3 Storage

Although well packaged, this equipment is not suitable for out­door storage. The equipment warranty will not be applicable if
there is evidence of outdoor storage. If the equipment is to be
stored indoors for any period of time, it should be stored with its
protective packaging material in place. Protect the equipment at
all times from excessive moisture, construction dirt, corrosive
conditions, and other contaminants.

It is strongly suggested that the package-protected equipment be
stored in a climate-controlled environment with temperatures
from -30 to 85°C (-22 to 185°F) and with a relative humidity of
80% or less. DO NOT, under any circumstance, stack other
equipment on top of a transfer switch equipment enclosure,
whether packaged or not.

-

-

2.2 Handling

As previously mentioned, ATS equipment is packaged for forklift
movement. Protect the equipment from impact at all times and
DO NOT double stack.

Once the equipment is at the installation location and ready to be
installed, packaging material can be removed and discarded.
Once the enclosure is unbolted from the wooden pallet, it can be
hand moved to its installation position. Be careful not to damage
the top or bottom enclosure mounting flanges. Refer to Section
4 of this manual for specific installation instructions.

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion

POWER PANEL

LOGIC PANEL

VOLTAGE SELECTION

AND TRANSFORMER PANEL

Contactor Based Transfer Switch

Section 3: Equipment Description

3.1 General

The ATS consists of three basic panels:

1. The power panel;

2. The voltage selection and transformer panel (if required); and

3. The microprocessor-based logic panel.

These panels are interconnected via connector plugs and
mounted in an enclosure (Figure 5

).

Instruction Booklet

Effective: September 2011 Page 7

Figure 5. Three Basic Panels of the ATS (40-400A).

3.2 Power Panel

The power panel is used for making load, power, and neutral con­nections. The power contactor is mounted on a steel baseplate
(Figure 6).

3.2.1 Main Contacts

This ATS incorporates a power contactor. The main contacts
connect and disconnect the load to and from the different power
sources. The power contactor is mechanically and electrically
interlocked to prevent the two sets of main contacts from being
closed simultaneously.

Figure 6. Typical Power Panel for 40-400A Models.

3.3 Voltage Selection

3.3.1 Standard Voltage Selection (208, 240, 480, 600, 
60 Hz and 220, 380, 415, 50 Hz.)

The Standard voltage selection panel consists of multi-tap trans­formers, contained in a steel case mounted in the enclosure (Fig­ure 7). The voltage is selected by
the default primary taps of both transformers and installing them
on the primary taps for the desired voltage. Taps are provided
for 208 to 600 Vac to satisfy application voltage. The factory
default position is 600 Vac.



simply removing the wires from

CAUTION

WHEN CHANGING THE SELECTED VOLTAGE, THE POWER MUST
BE REMOVED FROM THE ATS AND THE WIRES MUST BE MOVED
ON THE TAPS OF BOTH TRANSFORMERS.

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Instruction Booklet

Page 8 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Figure 7. Standard Voltage Selection Terminals (Shown
Connected to the 480 Vac Taps).

3.4 ATC-300+ Logic Panel

The ATC-300+ is a microprocessor-based transfer switch logic
control package. The hardware and software of the controller
contain the intelligence/supervisory circuits that constantly moni­tor the condition of the power sources. It provides the intelli­gence necessary for the operation of the ATS (Figure 8).

Figure 8. ATC-300+ Logic Control Panel.

The ATC-300+ controller has an operating temperature of 

-20 to 70°C (-4 to 158°F).

The controller circuit board is protected by an insulating confor­mal coating.

The specifications, under normal operating conditions, are as fol­lows:

■ Tolerance for voltage sensing function: ±1% of full scale

■ Tolerance for frequency sensing function: ±0.3 Hz of setting

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40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 9

3.5 Features

A variety of standard and optional features are available for Gen­erac ATSs. All features or combinations of features may not be
available on specific ATSs. All features and/or accessories are
Underwriters Laboratories (UL) listed unless noted.

3.5.1 Standard Features

The following is a list of the standard features for the ATC­300+ATC-300+ Controlled ATS.

1. Time Delay Normal to Emergency (TDNE)

This feature provides a time delay when transferring from
the Source 1 to the Source 2 power source. Timing begins
when Source 2 becomes available. It permits controlled
transfer of the load circuit to Source 2.

Adjustable 0 - 1800 Seconds

2. Time Delay on Engine Starting (TDES)

This feature provides a time delay of the signal to initiate

the engine/generator start cycle in order to override
momentary power outages or voltage fluctuations of
Source 1.

Adjustable 0 - 120 Seconds

3. Time Delay Emergency to Normal (TDEN)

This feature provides a time delay of the re-transfer opera­tion to permit stabilization of Source 1. Timing begins
when Source 1 becomes available. If Source 2 fails during
timing, then re-transfer is immediate overriding the time
delay.

Adjustable 0 - 1800 Seconds

4. Time Delay for Engine Cool-down (TDEC)

This feature provides a time delay of the signal to initiate
the engine/generator stop cycle after the re-transfer opera
tion. This allows the engine/generator to cool down by run­ning unloaded. Timing begins on completion of the re­transfer cycle.

Adjustable 0 - 1800 Seconds

5. Source 2 Monitoring and Protection

This feature provides monitoring and protection based on
the Source 2 voltage and/or frequency setpoints. All fea
ture 5 functions are Failsafe operations.

-

5H. Phase Reversal

For a 3-phase wye source, this feature monitors the phase

sequence of the sources. If a source does not have the
same ABC or CBA sequence as the setpoint value, that
source will be considered “Unavailable.

For a 3-phase delta source, this feature should be turned off
via the PHASE REV setpoint.

5J. All Phase Undervoltage and Underfrequency Protection

Adjustable Undervoltage:

Dropout: 78 - 97% of nominal
Pickup: (Dropout +2%) to 99% of nominal

Adjustable Underfrequency:

Dropout: 90 - 97% of nominal
Pickup: (Dropout +1Hz) to 99% of nominal

5K. All Phase Overvoltage/Overfrequency

Adjustable Overvoltage:

Dropout: 105 - 110% of nominal
Pickup: 103% to (Dropout –2%) of nominal

Adjustable Overfrequency:

Dropout: 103 - 105% of nominal
Pickup: 101% to (Dropout -1Hz) of nominal

-

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Instruction Booklet

Page 10 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

5L. Source 2 3-Phase Voltage Unbalance

For a 3-phase wye source, this feature monitors phase volt­age ratios. Voltage unbalance (%) is calculated as the dif­ference between the maximum and minimum phase
voltage, divided by the minimum phase voltage. User­selectable setpoints are available for dropout and pickup
unbalance settings (minimum 2% differential). Dropout is
adjustable from 5 to 20%. Pickup is adjustable from 3 to
(Dropout –2%). A setpoint for user-selectable time delay
from 10 to 30 seconds is provided. The factory default set­points are: 5% dropout, 3% pickup, and 30 seconds time
delay. A user-selectable setpoint for enable and disable is
also provided.

When an unbalance condition is detected on Source 2, the
Unbalance Timer (TD UNBAL) starts timing. After TD
UNBAL times out, Source 2 is declared “failed”.

For a 3-phase delta source, this feature should be turned off
via the VOLT UNBAL setpoint.

6. Test Operators

Generac ATSs are provided with a Test Pushbutton that
simulates a loss of the Source 1 power source as standard
(Feature 6B). All programmed time delays (TDNE, TDEN,
etc.) will be performed as part of the Test. Engine run time
of the Test is equal to the Plant Exerciser (Feature 23) pro
grammed setpoint. All Tests are Failsafe protected.

6B. Test Pushbutton

Programmable setpoints include:

1. Load or No Load Testing, or Disabled

2. Engine run time equal to the plant exerciser 
(Feature 23) setting

7. Time Delay Emergency Fail (TDEF)

This feature provides a time delay that prevents a con­nected Source 2 power source from being declared “Failed”
in order to override momentary generator fluctuations. If
the Source 2 power source remains in the failed state then,

0.5 seconds after the TDEF timer expires, the transfer

switch will proceed with the programmed sequence for
retransfer. This time delay is only implemented when the
Source 2 power source is a generator.

Adjustable 0 - 6 Seconds

8. Time Delay Bypass Pushbutton

This feature provides a way (by pushing the Help and Step
pushbutton simultaneously) to bypass the TDNE (Feature 1)
and/or TDEN (Feature 2) time delays. The Time Delay
Bypass function, when activated by pushing the Help and
Step pushbutton simultaneously, will reduce any or all of
the programmed time delay to zero.

8C. Bypass TDEN

This feature provides one set of pushbuttons to bypass the
TDEN time delay.

8D. Bypass TDNE

This feature provides one set of pushbuttons to bypass the
TDNE time delay.

12. Power Source Annunciation

This feature provides LEDs to give switch position and
power source availability indications.

Switch Position

Provides LEDs to indicate the switch position

12C. Source 1 - Source Connected

This feature provides a green LED that, when lit, indicates

the load is connected to Source 1.

12D. Source 2 - Source Connected

This feature provides a red LED that, when lit, indicates the

load is connected to Source 2.

Power Source Availability

Provides LEDs to indicate if a power source is available.

LEDs may be integral or separate from the controller.

12G. Source 1 - Available

This feature provides a white LED that, when lit, indicates

Source 1 is available.

12H. Source 2 - Available

-

This feature provides an amber LED that, when lit, indi-

cates Source 2 is available.

14. Relay Auxiliary Contacts

14G. Source 1 Present: Provides two (2) normally open and two

(2) normally closed contacts. The relay is energized when
Source 1 is available.

14H. Source 2 Present: Provides two (2) normally open and two

(2) normally closed contacts. The relay is energized when
Source 2 is available.

15. Switch Position Indication Contact

This feature provides a contact that indicates if the power
switching device is in the “Open” or “Closed” position.

15E. Source 1 Position Indication Contact

This feature provides 1 dry form “C” contact that indicates
the position of the Source 1 power switching device.

15F. Source 2 Position Indication Contact

This feature provides 1 dry form “C” contact that indicates
the position of the Source 2 power switching device.

23. Plant Exerciser (PE)

This feature provides a means for automatic testing of the

engine generator set or standby power system. All pro
grammed time delays will be performed during plant exer­ciser operations.

-

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40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 11

23K. Plant Exerciser Selectable – Disabled/1/7/14/28 Day Inter-

val

This feature provides for automatic test operation of the

generator. Available test cycles are daily, 7, 14, or 28
days with duration equal to the programmed engine test
time.

Programmable setpoints allow for selection of three test

cycles:

■ Engine Start/Run Only (No Load);

■ Exercise with Load Transfer; or

■ Disabled

This is a “Failsafe” operation.

26. Source 1 - Monitoring and Protection

This feature provides Source 1 monitoring and protection

functions. If the Source 1 power supply fails, then the
Automatic Transfer Controller will begin the sequence of
operations necessary to transfer the load circuit to the
Source 2 power supply. All Feature 26 monitoring and
protection functions are Failsafe operations.

26D. Go to Source 2

This feature provides the capability for an external contact
opening to initiate a load circuit transfer to the Source 2
power source. This includes starting the engine/generator,
performing the programmed time delays, and the transfer
operation. Re-transfer will occur when the external con
tact is closed or under a Failsafe condition.

26H. Phase Reversal Protection

For a 3-phase wye source, this feature monitors the phase

sequence of the sources. If a source does not have the
same ABC or CBA sequence as the phase reversal set
point, the source will be considered “Unavailable”.

For a 3-phase delta source, this feature should be turned

off via the PHASE REV setpoint.

26J. All Phase Undervoltage and Underfrequency Protection

Adjustable Undervoltage:

Dropout: 78 - 97% of nominal
Pickup: (Dropout +2%) to 99% of nominal

Adjustable Underfrequency:

Dropout: 90 - 97% of nominal
Pickup: (Dropout +1Hz) to 99% of nominal

26K. All Phase Overvoltage/Overfrequency

Adjustable Overvoltage:

Dropout: 105 - 110% of nominal
Pickup:103% to (Dropout –2%) of nominal

Adjustable Overfrequency:

Dropout: 103 - 105% of nominal
Pickup: 101% to (Dropout -1Hz) of nominal

-

-

26L. Source 1 3-Phase Voltage Unbalance

.For a 3-phase wye source, this feature monitors phase
voltage ratios. Voltage unbalance (%) is calculated as the
difference between the maximum and minimum phase
voltage, divided by the minimum phase voltage. User­selectable setpoints are available for dropout and pickup
unbalance settings (minimum 2% differential). Dropout is
adjustable from 5 to 20%. Pickup is adjustable from 3 to
(Dropout –2%)). A setpoint for user-selectable time delay
from 10 to 30 seconds is provided. The factory default
setpoints are: 5% dropout, 3% pickup, and 30 seconds
time delay. A user-selectable setpoint for enable and dis­able is also provided.

When an unbalance condition is detected on Source 1, the
Unbalance Timer (TD UNBAL) starts timing. After TD
UNBAL times out, Source 1 is declared “failed”.

For a 3-phase delta source, this feature should be turned
off via the VOLT UNBAL setpoint.

29. Alternate Transfer Modes of Operation

Provides standard or optional transfer modes, mode selec­tion devices, and operational methods for ATSs.

29J. Type of Operation (MANTR) Operation (new feature)

This feature provides for a selection between an automatic
transfer and re-transfer mode or a manual pushbutton re­transfer to Normal from the Emergency Source mode. If
this option is not selected the factory default selection is
automatic.

32. Delayed Transition Transfer Modes for Open Transition
Transfer Switches

This feature provides delayed transition transfer modes
for an open transition transfer switch. Often used in sys
tems with inductive loads, a delayed transition transfer
switch may prevent or reduce in-rush currents due to out
of phase switching of inductive loads.

32A. Time Delay Neutral

This feature provides a time delay in the neutral position
during the transfer and re-transfer operations during
which both Source 1 and Source 2 are disconnected from
the load circuit. The time delay is programmable and is
the same for both transfer and re-transfer operations.

Adjustable 0 - 120 Seconds

35. Pre-Transfer Signal

This feature provides a signal to a remote device prior to a

re-transfer operation. It provides one Form “C” contact
(NO/NC) for interface with other equipment (typically ele
vator controls). The contacts close/open on a timed basis
prior to transfer in either direction. After TDNE/TDEN
times out, this relay closes and the Pre-transfer Timer
(TPRE) starts timing. After the TPRE times out, the trans
fer proceeds by starting the TDN timer if enabled. The
pre-transfer relay opens after the transfer is complete.

Adjustable 0 - 120 Seconds

35A. Pre-Transfer Signal with 1 N.O. and 1 N.C. Contacts

This feature provides pre-transfer signal and includes 1

N.O. and 1N.C. contacts.

-

-

-

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 12 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

36. Emergency Inhibit (new feature)

This feature enables the Emergency inhibit control input to

inhibit transfers to the Emergency Source. See Control
Inputs section for more information.

This input is located on Pins 7 and 8 of Connector J8 and

is enabled when the Emergency Inhibit is enabled. The con
tact is closed for normal operation. Opening this contact
will activate the Emergency Inhibit input.

If the Emergency Inhibit contact is opened when the load is

connected to the Normal Source, no action will be taken if
the Normal Source is available. If the Normal Source is not
available, an immediate transfer to the neutral position will
occur.

If the Emergency Inhibit contact is opened when the load is

connected to the Emergency Source, the ATC-300+ will
transfer the load to the Normal Source if it is available. If
the Normal Source is not available, an immediate transfer
to the neutral position will occur.

The Emergency Inhibit input is only active when either

Source 1 or Source 2 is preferred. This input is not active
when the Preferred Source selection is set to None.

The Emergency Inhibit input takes priority over the Go To

Emergency input if both inputs are activated at the same
time. In this case, the generator will start but a transfer to
the Emergency Source will be inhibited until the Emergency
Inhibit input is de-activated.

42. Seismic Withstand Capability

Provides transfer switch with seismic capability exceeding

the worst case Zone 4 required per both the Uniform Build
ing Code and the California Building Code.

48F. RS-485 with Modbus Option

Provides communications for the ATC-300+ via Modbus

through an integrated RS-485 port. Registers are available
to read back status, voltages, frequencies, and historical
data. Registers are also available for transfer switch con
trol. Setpoints may be read back and/or programmed via a
pass-through command. See the ATC-300+ Modbus Com
munication Guide pn: 66A7787.

-

3.5.2 Optional Features

The following is a list of the optional features for the ATC-300+
Controlled ATS. All features or combinations of features may not

be available on specific ATSs

9B. Maintenance Selector Switch (MSS)

Marked “OFF”, “ON”. This feature provides selector
switch disconnection of control to transfer thus allowing
testing of the transfer switch control logic circuitry with
out initiating load transfer. Positioning the MSS in the
“OFF” position isolates the control circuit, permitting man
ual operation of the transfer switch or testing of logic cir­cuitry without load transfer. White indication light is lit ON
and display on ATC-300 controller shows “ATS NOT IN
AUTOMATIC” when the switch is in maintenance mode.

14. Relay Auxiliary Contacts: This feature provides form “C”
relay auxiliary contacts.

14C. Source 1 Present: Provides four (4) normally open and four

(4) normally closed contacts. The relay is energized when
Source 1 is available.

-

14D. Source 2 Present: Provides four (4) normally open and four

(4) normally closed contacts. The relay is energized when
Source 2 is available.

15. Switch Position Indication Contact

-

-

-

-

This feature provides a contact that indicates if the power
switching device is in the “Open” or “Closed position.

15G. Source 1 Position Indication Contact

This feature provides 3 Dry Form “C” contacts that indi­cate the position of the Source 1 power-switching device.

15H. Source 2 Position Indication Contact

This feature provides 3 Dry Form “C” contacts that indi­cate the position of the Source 2 power-switching device.

18. Metering

This feature includes all required external devices (CTs,
shorting blocks, fuses, etc.) for a fully functional metering
system.

18AN. IQ 250/260 Normal (S1) Only

18AE. IQ 250/260 Emergency (S2) Only

18AL. IQ 250/260 Load

18CN. IQ 110/115 Normal (S1) Only

18CE. IQ 110/115 Emergency (S2) Only

18CL. IQ 110/115 Load

18DN. IQ 130/140/150 Normal (S1) Only

18DE. IQ 130/140/150 Emergency (S2) Only

18DL. IQ 130/140/150 Load

18EN. PXM2250/2260/2270 Normal (S1) Only

18EE. PXM2250/2260/2270 Emergency (S2) Only

18EL. PXM2250/2260/2270 Load

18O. IQ Analyzer Normal (S1) Only

18P. IQ Analyzer Emergency (S2) Only

18Q. IQ Analyzer Normal (S1) & Emergency (S2) Switch Select-

able

18V. IQ Analyzer Load

18R. IQ DP-4000 Normal (S1) Only

18S. IQ DP-4000 Emergency (S2) Only

18T. IQ DP-4000 Normal (S1) & Emergency (S2) Switch Select-

able

18U. IQ DP-4000 Load

18W. Ammeter

A single ammeter is a true RMS sensing device that dis­plays single phase current only.

The ammeter can be mounted on Source 1, Source 2, or
load. The meter can also be configured for 1, 2, or 3-phase
sensing by supplying one meter per phase for Source 1,
Source 2, or load. Ammeters for both Source 1 and Source
2 can also be grouped together.

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 13

23L. 24 Hour, 7day, 365 Day Programmable Plant Exerciser

This plant exerciser has two channel electronic time
switches with 365-day, 7-day, 24-hour programming. Each
channel can be independently programmed and can provide
up to 400 events. The plant exerciser offers daily, weekly
or annual programming capability with up to 99 separate
holiday periods of any duration and priority. An LCD dis­play indicates load status, time-of-day, weekday and date.

29G. Auto/Manual Operation

This feature provides 2-position auto/manual selector

h marked “Auto/Manual” which permits the selec-

switc
tion of automatic or manual operation. Once the selector

ch is transferred to manual mode, manual transfer

swit
between Normal (S1) Neutral and Emergency (S2) can be
achieved by operating 3-position selector switch marked
“Normal-OFF-Emergency”. White indication light is lit ON
and display on ATC-300+ controller shows “ATS NOT
IN AUTOMATIC” when the switch is in manual mode.

38. Stainless Steel Logic Cover

38A. Stainless Steel Cover for Device Panel

Provides an added level of security by providing a pad

ble stainless steel cover for use with standard trans-

locka
fer switch device panel. The cover is designed for NEMA
1, 3R, 4X, and 12 a

38B. Stainless Steel Cover for Controller

Provides an added level of security by providing a pad

ble stainless steel cover for use with standard trans-

locka
fer switch logic controllers and/or associated device pan­els. These covers function with Generac’s ATC series
logic controller
designed for NEMA 1, 3R, 4X, and 12 applications.

41. Space Heater With Thermostat

This feature provides a space heater and non-adjustable

thermosta

41A. Space Heater With Thermostat - 100 Watt

This feature provides a 100 watt (W) spac

non-adjustable thermostat.

49B. Sensing Isolation Transformer (Up to 600 VAC only)

This feature provides 3-phase, 4-wire for Source-1 and

Sour
tance grounded delta system.

51D1. 50kA CVX Surge Device

This feature gives protection for surge current capacity

ting 50kA, up to 480VAC by providing a low imped-

ra
ance surge path to ground while supporting rated volt­age. It provides LED indication.

51F1. 100kA CVX Surge Device

This feature gives protection for surge current capacity

ting 100kA, up to 480VAC by providing a low imped-

ra
ance surge path to ground while supporting rated volt­age. It provides LED indication.

t. External control power is not required.

ce-2 sensing input on ATC controller for a high resis-

pplications.

s and device panels. The covers are

e heater with a

3.6 Enclosure

The rugged steel ATS enclosure is supplied with three door
hinges, regardless of enclosure size. They ensure proper support
of the door and door mounted devices (Figure 9). The hinges
have removable hinge pins to facilitate door removal. Certain
procedures, such as switch mounting, are simplified with the
door removed. The doors are supplied as standard with pad-lock­able latches.

Figure 9. Typical Type 1 Enclosure (Door Closed).

The door is used to mount a var
push-buttons, depending upon the options required for a particu­lar ATS. All lights and switches are mounted in the plastic door­mounted pa

nel.

iety of lights, switches, and

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 14 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

The rear of the enclosure is supplied with teardrop shaped
holes in the top and bottom mounting flanges to facilitate
mounting. It is also supplied with two positioning bolts
and various pre-tapped inserts to insure proper positioning
of the power panel anytime the power panel must be repo
sitioned to accommodate a different cable entry position.
Cable entry holes are the responsibility of the customer.

ATS enclosures and all internal steel mounting plates, such

as the power panel mounting plate, go through a pretreat­ment cleaning system prior to painting to ensure a durable
finish.

The standard ATS enclosure is NEMA 1 Type for general

use. However, a variety of enclosures are available to
address almost any environmental circumstance (see 
Table 3).

Table 3. Transfer Switch Equipment Enclosures

NEMA TYPE DESIGN PROTECTION

Open Indoor

1 Indoor Enclosed Equipment

3R Outdoor Rain, Ice Formation

12 Indoor Dust, Dirt, and

Non-Corrosive Liquids

3.7 Standards

Generac ATS equipment, enclosed in any of the enclosures listed
in Table 3, is listed for application by UL and ULC. In addition,

-

Generac ATSs are listed in File E38116 by Underwriters Labora
tories, Inc. under Standard UL 1008. This standard covers
requirements for automatic transfer switches intended for use in
ordinary locations to provide lighting and power as follows:

a. In emergency systems, in accordance with articles 517

and 700 in the National Electrical Code, ANSI/ NFPA 70,
and the National Fire Protection Association No. 76A;
and/or

b. In standby systems, in accordance with article 702 of the

National Electrical Code; and/or

c. In legally required standby systems in accordance with

article 701 of the National Electrical Code.

Generac ATSs are available to meet NFPA 110 for emergency
and standby power systems, and NFPA 99 for health care facili
ties when ordered with the appropriate options.

Standard UL 1008 for ATSs lists devices under the reexamination
program which only require a continual physical reexamination of
the components used in the product to ensure consistency with
the originally submitted device. Follow-up testing is not required
by UL 1008.

-

-

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 15

Section 4: Installation and Wiring

4.1 General

Generac ATSs are factory wired and tested. Installation requires
solidly mounting the enclosed unit and connecting power cables
and auxiliary pilot circuits. Physical mounting procedures and
power cable connections are covered in this section. All other
required wiring or electrical connection references are covered in
a separate Customer Wiring Booklet packaged with the ATS.

Locate the wiring schematic, review it, and ke
able for reference purposes during installation and testing. Once
an ATS
and electrically checked for proper installation and operation.
The procedures for these initial mechanical and electrical checks
are outlined in Section 6 of this instruction manual.

is properly installed and wired, it should be mechanically

WARNING

BE CERTAIN THAT THE SOLID STEEL DOOR IS PROPERLY
INSTALLED BEFORE THE TRANSFER SWITCH EQUIPMENT IS PUT
INTO SERVICE. THE DOOR PROVIDES PROTECTION FROM DAN­GEROUS VOLTAGES AT THE LINE AND
THE EQUIPMENT IS IN OPERATION. FAILURE TO DO SO COULD
RESULT IN PERSONAL INJURY OR DEATH.

LOAD TERMINALS WHEN

4.2 Mounting Location

Choose a location that offers a flat, rigid mounting surface capa­ble of supporting the weight of the enclosed ATS equipment.

standard ATSs, avoid locations that are moist, hot, or dusty.

For
However, Generac offers optional enclosure designs that can be
used in special environments. If there are any doubts as to a
location’s suitability, discuss them with your Generac representa­tive.

Check to make certain that there are no pipes, wires, or other
mounting hazar
ate a problem.

Carefully remove all packing mater
ing location. Even though an equipment inspection should have
been ma
careful inspection of the enclosure and the enclosed ATS compo­nents as the packing material is removed and the enclosure read­ied for mounting. Be especially aler
wires, or damaged components.

ds in the immediate mounting area that could cre-

ial from the ATS at the mount-

de when the equipment was received, make another

t for distorted metal, loose

ep it readily avail-

4.3 Mounting Procedure

CAUTION

SINCE THE ENCLOSED ATS MUST BE LIFTED INTO PLACE FOR
MOUNTING, BE CERTAIN THAT ADEQUATE RESOURCES ARE
AVAILABLE FOR LIFTING TO AVOID PERSONNEL INJURIES OR
EQUIPMENT DAMAGE.

All equipment enclosures and power panels are of the same
design. Only the overall physical dimensions change. Note that
the enclosure is provided with four teardrop (elongated) mount­ing holes, two in the top mounting flange and two in the bottom.

Cable entry holes are not part of the enclosure when shipped
from the factory and must be pr
or after mounting the enclosure. Cable access may be from the
top, bottom, and/or side.

ovided in the field, either before

CAUTION

EXTREME CARE SHOULD BE TAKEN TO PROTECT THE TRANSFER
SWITCH FROM DRILL CHIPS, FILINGS, AND OTHER CONTAMI­NANTS WHEN MAKING THE CABLE ENTRY HOLES. EXTREME
CARE SHOULD ALSO BE TAKEN WHEN MOUNTING THE ENCLO­SURE TO PREVENT COMPONENT DAMAGE OR A FUTURE MAL­FUNCTION.

IB01602078E For more information visit: www.generac.com

Figure 10.Typical (40A-400A) Contactor Based ATS 
Equipment (Door Open).

Instruction Booklet

ATC-300

Electrical

ase

ase

Source 1

Source 2

Available

Available

Connected

Connected

Load

Unit Status

Alarm
Reset

Engine
Test

Lamp
Test

Help

Step

Enter

Bypass

TDNE / TDEN

Page 16 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

With the enclosed ATS equipment unpacked and ready for
mounting, proceed with the following steps.

Step 1: The ATS enclosure door is hinge mounted with remov-

able hinge pins. To simplify the mounting procedure and

void damaging the door-mounted logic panel, it is

a
strongly suggested that the door be carefully removed
and put it in a safe place until mounting is complete. To
remove the door, open the door and disconnect the con­nectors at the back of the ATC-300+ logic panel.
Remove the wire

ties securing the harness to the inside
of the door. Carefully remove the hinge pins then the
door from the enclosure.

Step 2: Insta

ll the required upper and lower mounting bolt
anchors and the two upper mounting bolts in the mount­ing surface.

Step 3: Gently lift the enclosure and guide the tear

drop holes in
the upper mounting flange over the upper mounting
bolts. Do not completely tighten the bolts at this time.

Step 4: Wh

ile still supporting the enclosure, install the two lower
mounting bolts in the lower mounting flange. Again, do
not completely tighten the bolts at this time. Use shims,
if required, to prevent deformation of the enclosure if the
mounting surface is distorted.

Step 5: T

ighten all four mounting bolts after any required shim-

ming is completed.

4.4 Power Cable Connections

WARNING

POWER CONDUCTORS MAY HAVE VOLTAGE PRESENT THAT CAN
CAUSE SEVERE PERSONAL INJURY OR DEATH. DE-ENERGIZE ALL
POWER OR CONTROL CIRCUIT CONDUCTORS TO BE CONNECTED
TO THE ATS EQUIPMENT BEFORE BEGINNING TO WORK WITH THE
CONDUCTORS AND/OR TERMINATING THEM TO THE EQUIPMENT.

CAUTION

USE OF CABLE LUGS NOT DESIGNED FOR THE ATS MAY CAUSE
HEATING PROBLEMS.

CAUTION

TO HELP PREVENT COMPONENT DAMAGE OR FUTURE MALFUNC­TIONS, USE EXTREME CARE TO KEEP CONTAMINANT
THE ATS EQUIPMENT WHEN MAKING POWER CABLE CONNEC­TIONS.

S OUT OF

CAUTION

RUN THE POWER CABLE THROUGH THE GUTTER SPACE PROVIDED
TO THE RIGHT OR LEFT OF POWER PANEL.

Figure 11.Typical Mounting of the ATS to a Mounting Surface.

Step 6: Double che

ck to ensure that all packing and shipping

materials have been removed.

Test all power cables prior to connection to the unit to ensure
that the conductors or cable insulation have not been damaged
while being pulled into position.

Power cables are to be connected to solderless screw type lugs

ted on the ATS switching devices. Refer to the separate Cus-

loca
tomer Wiring Booklet supplied with the ATS equipment for power
termination. Ve

rify that the lugs supplied will accommodate the
power cables being used. Also verify that the cables comply with
local electrical codes. Standard ATS equipment, as supplied from
the factory, will accommodate the wire sizes shown in Table 4.

Carefully strip the insulation from

the power cables to avoid nick­ing or ringing of the conductor strands. Prepare the stripped con­ductor termination end by cleaning it with a

wire brush. If
aluminum conductors are used, apply an appropriate joint com­pound to the clean conductor surface area.

WARNING

IMPROPER POWER CABLE CONNECTIONS CAN CAUSE EXCESSIVE
HEAT AND SUBSEQUENT EQUIPMENT FAILURE.

Tighten the cable lugs to the torque identified on the label affixed
to the door of the unit.

For more information visit: www.generac.com IB01602078E

Instruction Booklet

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Table 4. Transfer Switch Equipment Wire Sizes

TRANSFER SWITCH AMPERE RATING WIRE SIZE RANGES NUMBER OF CABLES PER PHASE TERMINAL TEMPERATURE RATING °C (°F)

100 #14-2/0 1 75 (167)

200 #6-250 KCMIL 1 75 (167)

320 #4-600 KCMIL or (2) 1/0-250 KCMIL 1 or 2 - depending on wire size used 75 (167)

400 #4-600 KCMIL or (2) 1/0-250 KCMIL 1 or 2 - depending on wire size used 75 (167)

4.5 Wiring

Effective: September 2011 Page 17

POWER CONDUCTORS AND CONTROL WIRING MAY HAVE VOLT­AGE PRESENT THAT CAN CAUSE SEV
DEATH. DEENERGIZE ALL POWER OR CONTROL CIRCUIT CON­DUCTORS BEFORE BEGINNING TO PERFORM ANY WIRING ACTIV­ITY TO OR WITHIN THE ATS EQUIPMENT.

Power sources, load conductors, and control wiring should be
connected to locations as indicated in the Customer Wiring Book­let supplied with the ATS equipment.

WARNING

ERE PERSONAL INJURY OR

CAUTION

ENSURE THE ATS VOLTAGE IS SET CORRECTLY. IT SHOULD BE
THE SAME AS THE SOURCE 1 AND SOURCE 2 LINE VOLTAGES.
OPERATING THE EQUIPMENT ON IMPROPER VOLTAGE CAN
CAUSE EQUIPMENT DAMAGE.

Once the ATS equipment has been installed and wired, perform
the initial mechanical and electrical procedures as outlined in Sec­tion 6 to verify that the equipment is installed and operating

ly.

proper

4.6 Engine Start Connection

The engine control contact connections are located on the logic
panel of the ATS. Connect the engine start wires to the termi­nals marked 13 and 14 on J-5 connector on the ATC-300+ Con­troller (see Figure 12). A contact closes between these terminal
when an e
wiring diagram provides additional engine start connection infor­mation. Use the proper wire size as listed by the generator set
(Ge

ngine start signal is provided by the ATS logic. The

nset) manufacturer.

NOTICE

PRIOR TO MAKING THE ENGINE START CONNECTION TO THE
SWITCH, SET THE ENGINE GENERATOR CONTROLS SELECTOR
SWITCH IN THE OFF POSITION TO PREVENT AN UNWANTED
ENGINE START. CONTROL WIRING, SUCH AS THE ENGINE START
WIRES, MUST BE RUN IN A SEPARATE CONDUIT FROM THE
POWER CABLES.

IB01602078E For more information visit: www.generac.com

123

4

5678

9

10

11 12 13

14

123

4

5678

9

10

11 12 13

14

123

4

5678

9

10123

4

5678

9

10

J5

J7

J2

J1

J4

7

6

5

4

3

4

J3

Phase C

Phase B
Phase A

Source 1

Phase C

Phase B
Phase A

Source 1

Phase C

Phase B
Phase A

Source 2

Phase C

Phase B
Phase A

Source 2

S1 - Line
S1 - Neut

S2 - Line

Control
Power

S2 - Neut

Clk

In

Out

5V

Gnd

Programming

Port

K1 - (Com)

K1 - (NO)

K2 - (Com)

K2 - (NO)

Pretransfer - (Com)

Pretransfer - (NO)

Pretransfer - (NC)

Alarm - (Com)

Alarm - (NO)

Alarm - (NC)

Earth Ground

Gen Start - (Com)

Gen Start - (NO)

Output Relays

+32 VDC

Source 1 Closed

+32 VDC

Source 2 Closed

+32 VDC

Lockout

+32 VDC

Go To Source 2

+32 VDC

Monitor Mode

Control Inputs

8.0 in.

6.5 in.

3

4

1

2

7

8

5

6

Output
Relays

Control
Inputs

J8

K4 NO
K4 C om

K3 NO
K3 Com

2

1

Rx

Tx

Emergency
Inhibit

Manual
Re-Transfer

J10

3

4

2

1

RS485
Termination

RS-485
MODBUS

A

B

Com

SHD

1

ON

S2
Close

S1
Close

S2

Open

S1

Open

TERMINALS 13 & 14

ATC-300+ Controller - 2 Position Contactor type (In-Phase) - CAT#8160A00G27

ATC-300+ Controller - 3 Position Contactor type (TDN) - CAT#8160A00G28

Instruction Booklet

Page 18 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Figure 12. Location of Terminals 13 and 14 on the J-5 Connector of ATC-300+ Controller.

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

4.7 Voltage Selection Adjustments

Certain devices, such as the Voltage Selection Panel, sensing
relays, and timers, need to be set and/or calibrated prior to plac­ing the ATS equipment in service. Adjustments for logic devices

described in the separate instructional document dedicated to

are
the specific logic being used. Voltage selection adjustments are
described in this section.

CAUTION

BE SURE THAT THE CORRECT VOLTAGE IS SELECTED TO MATCH
THE SYSTEM VOLTAGE. AN IMPROPER SELECTION AND/OR CON­NECTION COULD RESULT IN EQUIPMENT DAMAGE.

4.7.1 Standard Voltage Selection Panels (208, 240, 480, 
600 V, - 60 Hz & 220, 380, 415 V, -50 Hz

The Standard voltage selection panel consists of multi-tap trans­formers, contained in a steel case mounted in the enclosure. To

the voltage from the factory default 600 Vac, follow the

change
steps detailed below.

Step1: Loos

Step 2: Remove th

en the six screws securing the cover of the Voltage
Selection Transformer case. Slide the cover up, then
away from the case.

formers and installed them on the taps for the desired
volta
former is moved since the second wire is the zero refer­ence.

e wires from the primary taps of both trans-

ge (Figure 13B). Note that only one wire per trans-

)

Instruction Booklet

Effective: September 2011 Page 19

Figure 13A. Standard Voltage Selection Panel.

CAUTION

WHEN CHANGING THE VOLTAGE, ONE WIRE MUST BE MOVED ON
THE PRIMARY TAPS OF BOTH TRANSFORMERS.

Figure 13B. Standard Voltage Selection Panel.

Figure 13.

Step 3: Re

install the cover and tighten the four screws.

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Instruction Booklet

TOOL HOLE

WIRE HOLE

Page 20 Effective: September 2011

4.8 Terminal Block Wire Installation and Removal

Proceed with the following steps and associated figures to install
or remove terminal block wiring.

Step 1: Figure 1

There is a large one and small one, but the operation is
the same for both. A small tool, such as a screwdriver,
will be pushed into the square hole next to the wire hole
and a wire will be inserted into the larger circular hole on
the outer edge.

4 shows two tension clamp terminal blocks.

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Figure 16. Wire Inserted in the “Wire” Hole.

Step 4: Wh

ile holding the wire in place, pull the screwdriver out.
The wire will now be held securely in the terminal block.
Pull on the wire to insure that it is correctly inserted into
the clamp.

Figure 14. Tension Clamp Terminal Blocks.

Step 2: Be

gin by inserting a small, flathead screwdriver into the
square (tool) hole with the flat surface of the screwdriver
against the back wall of the hole. With a little bit of
force, push the screwdriver in on a slight angle toward
the center of the clamp. Be sure to slide it in until it
clicks. You will then see the clamp open in the wire hole.

Figure 17. Wire Securely Installed in the Terminal Block.

Figure 15. Screwdriver Inserted in the “Tool” Hole.

Step 3: Once the sc

(strip about 1/4 in.) and insert it into the larger circular
wire hole. Push the wire in until it can go no further.

rewdriver is in place, obtain a stripped wire

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Section 5: Operation

5.1 General

An ATS provides a power contactor to connect and disconnect
the load to and from the Source 1 and Source 2 power sources
(Section 3.2.1).

5.2 Manual Operation

Instruction Booklet

Effective: September 2011 Page 21

DO NOT ATTEMPT TO MANUALLY OPERATE THE ATS WITH
SOURCE 1 OR SOURCE 2 AVAILABLE.

WARNING

WARNING

HIGH VOLTAGES ARE PRESENT IN AND AROUND TRANSFER
SWITCH EQUIPMENT. BEFORE ATTEMPTING TO MANUALLY
TRANSFER, DISCONNECT THE LINE POWER FROM THE EQUIP­MENT BEING SERVICED BY OPENING
BLE, THE NEXT HIGHEST DISCONNECT DEVICE. FAILURE TO
FOLLOW THIS PROCEDURE COULD CAUSE SEVERE PERSONAL
INJURY AND/OR DEATH.

ALWAYS TURN THE SOURCE 1 POWER OFF AND TURN THE

URCE 2 (IF A GENERATOR) CONTROL SELECTOR SWITCH TO

SO
THE “OFF” POSITION BEFORE ATTEMPTING A MANUAL TRANS­FER.

To manually operate:

1. Disconnect all sources of power.

2. Disconnect the J7 connector from the ATC-300+ controller.

3. Locate the manual lever on the left side of the contactor.

4. Locate the handle used to manually transfer the switch.

5. Attach the handle to the manual lever (See Figure 18).

6. Rotate the lever down to go to open or trip the unit.

7. Depress the “close” button located on the operating mecha­nism of the contactor to bring the contactor
position.

8. Rotate the lever down to open or trip the unit.

9. Depress the “source select” button on the operating mecha­nism of the contactor and depress the “close” button while

ping the “source select” button depressed to go to

kee
Source-2.

AND LOCKING OUT, IF POSSI-

to the Source-1

Figure 18. ATS Manual Operating Handle in Use.

10. Once the manual operation is complete and automatic opera­tion is desired, connect the sources of power.

11. Check for 120 Vac at J7-2 to J7-1 if Source 1 is available.

12. Check for 120 Vac at J7-4 to J7-3 if Source 2 is available.
See the Tr
800 Controller Instruction Booklet I.B. ATS-C103) if values
are above 130 Vac or below 110 Vac.

13. Insert the J7 connector into the controller.

14. Follow the testing procedure in Section 6 to ensure proper

utomatic operation.

a

oubleshooting Guide (Table 3, Section 6 of ATC-

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 22 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

5.3 Automatic Transfer

The operating sequence of an ATS is dictated by the switch's
standard features and selected options. Operation of an ATS dur­ing Source 1 power source failure and Source 1 power source

ration will be described here with only standard options

resto
included on the switch. Additional options, as described in Sec­tion 3, can change sequences and timing, depending upon the

ns selected. It is strongly suggested that you become famil-

optio
iar with additional options selected with the particular ATS and
their effect on the

5.3.1 Source 1 Power Source Failure

Standard Source 1 power source failure is defined as a reduction
or loss of voltage. If this occurs, the sequence of operation is as
follows.

1. Failure of Source 1 is detected by

2. When the controller detects a failure, the engine contacts

3. When the Source 2 voltage reaches its operation rating, the

4. The load is now transferred to the Source 2 power source.

(after delay if programmed) and start the engine-driven

close
generator.

K2 and K4 re
transfer operation to Source 2. This operating sequence
causes the contactor to open Source 1 and close on 
Source 2.

5.3.2 Source 1 Power Source Restoration

1. A return to the Source 1 power source begins when the volt­age in all phases of a 3-phase sensing unit, or phase-to-pha
in a single sensing unit, is restored to a preset value.

2. At the preset voltage, K1 and K3 relays inside ATC 300 con­troller operate to start transfer

3. During this sequence, the contactor opens Source 2 and

4. Simultaneously, the engine cool-down timer initiate

5. Transfer of the load back to the Source 1 power source is

s on Source 1.

close

down of the engine driven generator.

now complete.

normal operation of an ATS.

the controller intelligence.

lays inside ATC 300 controller operate to start

se

operation to Source 1.

s the shut

Section 6: Testing and Problem Solving

6.1 Testing

After the ATS equipment is initially installed or during planned
outages, the installation should be tested to ensure that all equip­ment operates properly. This attention t
unexpected malfunctions. Mechanical and/or electrical tests
should be performed as described in this section.

The frequency of subsequent testing should be base
mendations of the Genset manufactur
to check the electrical operation of the switch.

WARNING

HIGH VOLTAGES ASSOCIATED WITH OPERATIONAL TRANSFER
SWITCH EQUIPMENT PRESENT A SHOCK HAZARD THAT CAN
CAUSE SEVERE PERSONAL INJURY OR DEATH. USE EXTREME
CAUTION TO AVOID TOUCHING ELECTRICAL CONNECTIONS
WHENEVER INSPECTING OR TESTING THE EQUIPMENT.

IN ADDITION, IMPROPER OPERATION OF THE GENERATOR SET

NTS A HAZARD THAT CAN CAUSE SEVERE PERSONAL

PRESE
INJURY OR DEATH. OBSERVE ALL SAFETY PRECAUTIONS IN YOUR
GENERATOR SET OPERATIONS AND INSTALLATION MANUALS.

6.1.1 Mechanical and/or Electrical Testing

NOTICE

SINCE FEATURE 4 (TIME DELAY ENGINE COOL-OFF), AS
DESCRIBED IN SECTION 3, IS A STANDARD FEATURE, AN ENGINE
START SIGNAL WILL BE PRESENT FOR A PERIOD OF TIME WHEN
THE S WI TCH IS FI RS T ENER GI ZE D. THE PE RIOD OF T IM E IS EQ UA L
TO THE TIMER SETTING. TO AVOID STARTING THE ENGINE DUR­ING THIS TIME PERIOD, TURN THE GENERATOR CONTROLS TO

E OFF POSITION.

TH

Energize the ATS equipment as described in Sections 6.1.2
through 6.1.6. Insure that all safety precautions are taken and
that all WARNINGS and CAUTIONS are observed.

6.1.2 No Voltage Steps

With no voltage available on either power source, proceed as fol­lows.

Step 1: The

Step 2: Ensure that the

Step 3: Check

6.1.3 Connecting the Power Sources

Step 1: Close the Source 1 power source upstream protection

Step 2: Connect the engine sta

Step 3: With the emer

generator engine start controls should be in the OFF

position to prevent an undesired start.

ATS has been set to the proper applied

system voltage (See Section 4.7).

all ATS loads to ensure that they are ready to be

energized.

device.

rt battery cable.

gency generator in the OFF position, close
the Source 2 power source upstream protective device,
assuming such a device used.

o detail will help avoid

d on recom-

er. Use the test pushbutton

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 23

NOTICE

AT THIS POINT, AND PRIOR TO MAKING ANY ATTEMPT TO ENER­GIZE THE ATS EQUIPMENT, THE ENGINE-DRIVEN GENERATOR
SHOULD BE OPERATED. IF NECESSARY, THE VOLTAGE REGULA­TOR ON THE GENERATOR SHOULD BE ADJUSTED ACCORDING TO
THE MANUFACTUR
MENT WILL RESPOND ONLY TO THE RATED VOLTAGE AND FRE­QUENCY PROGRAMMED INTO THE CONTROLLER.

Step 4: Close any generator engine-start controls opened as a

Step 5: Where required, use an accurate voltmeter to check

result of actions taken in Step 1, Section 6.1.2.

phase-to-phase and phase-to-neutral voltages present at
the transfer switch Source 1, Source 2, and/or load ter­minals.

6.1.4 Operational Checks

Step 1: Check to ensure that Source 1 switching device is in the

Step 2: Initiate an automatic trans

Note:The ATC-300+ Logic Controller provides the capability to set the

Engine Test function to:

The factory default is set to 0 - No Load Engine Test:

Step 3: Initiate an automatic transfer operation back to the

CLOSED position. This should have been done in Section

6.1.3, Step 1.

1 to the Source 2 power source by pressing the <Engine
Test> pushbutton two times.

0. No Load Engine Test;

1. Load Engine Test; or

2. Disabled.

1. Load Engine Test

a. After the Time Delay Engine Starting (TDES) has timed out,

b. The transfer switch will transfer to the Source 2 power

Source 1 power source by pressing the <Engine Test>
pushbutton one time.

1. After the Time Delay Emergency to Normal timer
(TDEN) has timed out, t
back to the Source 1 power source.

2. The Time Delay for Engine Cool-Off (TDEC - Feature 4)
will allow the eng
after transfer to the Source 1 power source is com­pleted.

6.1.5 Alternate Tests

1. Alternate operational tests may be possible depending upon
the options provided with any given ATS. Refer to the sche­matic diagram provided with the ATS equipment, along with
the spec
provided.

ER’S RECOMMENDATIONS. THE ATS EQUIP-

fer operation from the Source

the engine should start, run, and build up to normal voltage
and frequency.

source after the Time Delay Normal to Emergency (TDNE)
times out.

he transfer switch will transfer

ine to run unloaded for a preset time

ification nameplate, to determine the exact options

WARNING

DO NOT ATTEMPT TO MANUALLY OPERATE THE ATS WITH THE
SOURCE 1 POWER SOURCE CONNECTED AND AVAILABLE.

DO NOT ATTEMPT TO MANUALLY OPERATE THE ATS WITH THE

URCE 2 POWER SOURCE CONNECTED AND AVAILABLE.

SO

6.2 Problem Solving

WARNING

HAZARDOUS VOLTAGES IN AND AROUND ATS EQUIPMENT DUR­ING THE PROBLEM SOLVING PROCESS CAN CAUSE SEVERE PER­SONAL INJURY AND/OR DEATH. AVOID CONTACT WITH ANY
VOLTAGE SOURCE WHILE PROBLEM SOLVING.

WARNING

ONLY PROPERLY TRAINED PERSONNEL, FAMILIAR WITH THE ATS
EQUIPMENT AND ITS ASSOCIATED EQUIPMENT, SHOULD BE PER­MITTED TO PERFORM THE PROBLEM SOLVING FUNCTION. IF AN

DIVIDUAL IS NOT QUALIFIED TO PERFORM THE PROBLEM SOLV-

IN
ING FUNCTION, THE INDIVIDUAL SHOULD NOT ATTEMPT ANY OF
THESE PROCEDURES

A basic problem-solving effort is the first step to take prior to
calling for assistance. Frequently, the effort will successfully
address most problems encountered. The problem solving proce­dure is presented in the Troubleshooting Guide (Table 3, 
Section 7 of ATC 300 Controller Instruction Booklet
IB01602009E). R
with the ATS equipment and the system in which it is applied
should attempt these problem solving procedures.

If a problem persists after having completed the problem solving

ocedure, contact a Generac representative for further assis-

pr
tance. When calling for assistance, the following is the minimum
information r

1. Style number of ATS, if applicable;

2. Catalog number of ATS;

3. Actual location of the ATS (type of facility, address, etc.);

4. Company name and name and position of individual repre­senting company;

5. Basic description of the situation as it exists; and

6. Any results of the problem solving steps taken and/or read­ings taken.

equired to properly address the need:

.

emember, only qualified individuals familiar

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 24 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Section 7: Adjustments

7.1 General

Refer to I.B. 01602009E, supplied with the ATS for ATC-300+
Controller adjustments and programming.

Section 8: Maintenance

8.1 Introduction

WARNING

HIGH VOLTAGES ARE PRESENT IN AND AROUND ATS EQUIPMENT.
BEFORE INSPECTING OR MAINTAINING THIS EQUIPMENT, DISCON­NECT THE LINE POWER FROM, THEN LOCK OUT, IF POSSIBLE, THE

T HIGHEST DISCONNECT DEVICE. FAILURE TO FOLLOW THIS

NEX
PROCEDURE COULD CAUSE SEVERE PERSONAL INJURY AND/OR
DEATH.

In general, ATS switch equipment is designed to be relatively
maintenance free under normal usage. However, because of the
variability of application conditions and the importance placed on
dependable operation by this type of equipment, inspection and
maintenance checks should be made on a regularly scheduled
basis. Since equipment maintenance will consist mainly of keep­ing the equipment clean, the f
depend to a large extent on the cleanliness of the equipment’s
surroundings. If a significant amount of dust or foreign matter is
present, a more frequent maintenance schedule should be fol­lowed.

It is suggested that visual inspections of the equipment be made

egular basis, not just during scheduled periods. Always be

on a r
alert for an accumulation of dirt in and around the structure; loose
parts; and/or hardware, cracks, and/or discoloration to insulation;
and damaged or discolored components.

requency of maintenance will

8.2 Procedures

A suggested maintenance procedure is outlined in Table 5.

Table 5. Periodic Maintenance Procedures

STEP ACTION

a. Make the ATS equipment safe for inspection and/or maintenance. Disconnect the line power from equipment being serviced by opening the next highest disconnect device. Make

b. Inspect the structure area for safety hazards or potential maintenance problems. Inspect the area, especially where switching device is installed, for any safety hazards, including personnel

c. Inspect the power contactor for dust, dirt, soot, grease, moisture, or corrosion. Remove dust, dirt, soot, grease, moisture, and corrosion contamination from the surface of the switching device

d. Check for material integrity, uneven wear, discoloration, or loose hardware. Severe material cracking will require replacement and loose hardware will need to be tightened.

e. Check the terminals and connectors for looseness or signs of overheating. Overheating will show as discoloration, melting, or blistering of the conductor insulation.

f. Contact Inspection Procedure Carefully remove the arc chute clips using needle nose pliers. Remove the arc chutes to inspect the contacts.

g. Exercise the power contactor if it is not often exercised while in operation. 

This will permit a “wiping” action by the contacts.

h. Return the ATS equipment to service. Make certain all barriers are in place and doors closed. Reapply secondary and primary power.

certain that any accessory control power is switched off by disconnecting all control plugs.

safety and fire hazards. Exposure to certain chemical vapors can cause deterioration of electrical connections.

Inspect for accumulated dirt, loose hardware, or physical damage.

Examine the primary insulation for evidence of cracking or overheating. Overheating will show as discoloration,
melting, or blistering of conductor insulation, or as pitting or melting of conductor surfaces due to arcing.

Inspect the secondary control connections for damage and the control wiring for insulation integrity.

using a dry soft lint-free cloth, dry soft bristle brush, and vacuum cleaner. Do not blow debris into the power
contactor. If contamination is found, look for the source and fix the problem.

Connections that do not have signs of looseness or overheating should not be disturbed.

Contact Generac if the contacts have excessive wear. Reinstall the arc chutes and arc chute clips, making sure
the ends of the clips are fully seated in the grooves on the barriers.

If the power contactor is used for frequent switching during normal operation, this step can be disregarded.

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

SECTION 9: RENEWAL PARTS GUIDE

Instruction Booklet

Effective: September 2011 Page 25

9.1 General

Refer to Figure 19 for assistance with selecting and ordering
selected ATS renewal parts. For more information, please see
Renewal Parts Publication (RP01603002E).

Example: To order

ATC3C3X30400WRU transfer switch, order Catalog

Number as shown in Figure 19, below.

the ATC-300+ Controller for an



ATC-300+ Controller - 3 Position Contactor type (In-Phase) - CAT#8160A00G27

Transformer Pack 400A, 2-Pole, 3-Pole, 4-Pole - Cat# 68C8229G02

Contactors (400A) 400A, 480VAC, 2-Pole - Cat# 69C2990G01

Wire Harness (400A
Contactor)

Lugs (400A Contactor) Up to 400A - Cat# AB-750-4

100W Space Heater Domestic Switch, up to 600VAC - Cat# 8160A41G54

Figure 19. Typical ATC-300+ Controlled Contactor Based ATS.

IB01602078E For more information visit: www.generac.com

400A, 480VAC, 3-Pole - Cat# 69C2990G02
400A, 480VAC, 4-Pole - Cat# 69C2990G03

200A, 600VAC, 2-Pole - Cat# 69C2990G01
200A, 600VAC, 3-Pole - Cat# 69C2990G02
200A, 600VAC, 4-Pole - Cat# 69C2990G03

AG Switch, up to 240VAC, 2-Pole - Cat# 68C8189G05 + 68C8189G06
AG Switch, up to 240VAC, 3-Pole, 1-Phase - Cat# 68C8189G05 + 68C8189G09
AG Switch, up to 240VAC, 3-Pole, 3-Phase - Cat# 68C8189G05 + 68C8189G07
AG Switch, up to 240VAC, 4-Pole - Cat# 68C8189G05 + 68C8189G08

Domestic Switch, up to 600VAC, 2-Pole - Cat# 69D8301G02 + 68C8189G35
Domestic Switch, up to 600VAC, 3-Pole - Cat# 69D8301G02 + 68C8189G35
Domestic Switch, up to 600VAC, 4-Pole - Cat# 69D8301G02 + 68C8189G35

Instruction Booklet

ase

ase

Page 26 Effective: September 2011

Section 10: ATC-300+ Controlled ATS
Quick Start Instructions

WARNING

THESE QUICK START INSTRUCTIONS ARE NOT A COMPLETE
SOURCE OF INFORMATION ON THE ATC-300+ CONTROLLED ATS
EQUIPMENT. INSTALLATION SHOULD NOT BE STARTED UNTIL
THE ENTIRE INSTRUCTION BOOK HAS BEEN REVIEWED AND
UNDERSTOOD. FAILURE TO FOLLOW THE FULL INSTRUCTIONS
CAN RESULT IN DEATH, SEVERE PERSONAL INJURY, OR PROP­ERTY DAMAGE.

WARNING

THESE QUICK START INSTRUCTIONS ARE PROVIDED FOR USE
ONLY BY TECHNICIANS HIGHLY FAMILIAR AND EXPERIENCED
WITH ATC-300+ CONTROLLED ATS EQUIPMENT INSTALLATION,
SET UP, AND TESTING. IT IS STRONGLY SUGGESTED THAT THE
FULL INSTRUCTIONS BE FOLLOWED FOR ALL INSTALLATIONS,
SET UP, AND TESTING.

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Electrical

Unit Status

ATC-300

Available

Source 1

Connected

Load

Available

Connected

Source 2

Help

Step

Engine

Lamp

Test

Enter

Test

Alarm

Bypass

Reset

TDNE / TDEN

Step 1: Mount the ATS on a flat rigid surface (Figure 20). Shim if

necessary.

Figure 20. Mounting Details.

Step 2: Install the powe

r cables. Cables must be sized and
installed per National Electrical Code, refer to NFPA70.
The cables must be sized within the specified cable size
range on the side of the cable connectors.

Connect the cables and torque to the correct value indi­cated on the label on the door in the following order:

1.Load Cables* (T1, T2, T3);

2.Source 1 or Utility Supply (N1, N2, N3); and

3.Source 2 or Generator Supply (E1, E2, E3).

For 4 pole transfer switches, connect the load cables

(TN), Sour

ce 1 or utility supply (NN), and Source 2 or
generator supply (EN). Refer to Figure 21 for the location
of all parts discussed in this document.

*Load cables MUST be connected and torqued BEFORE

installing the SUP

PLY cables (Figures 21).

Shim if Necessary

For more information visit: www.generac.com IB01602078E

NEUTRAL

CONNECTION

TRANSFER

MECHANISM

LOAD LUGS

EMERGENCY LUGS

NORMAL LUGS

LOGIC PANEL

VOLTAGE SELECTION AND
TRANSFORMER PANEL

GROUND

CONNECTION

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 27

Figure 21. 400A, 3-Pole, ATS Interior Components.

IB01602078E For more information visit: www.generac.com

Instruction Booklet

123

4

5678

9

10

11 12 13

14

123

4

5678

9

10

11 12 13

14

123

4

5678

9

10123

4

5678

9

10

J5

J7

J2

J1

J4

7

6

5

4

3

4

J3

Phase C

Phase B
Phase A

Source 1

Phase C

Phase B
Phase A

Source 1

Phase C

Phase B
Phase A

Source 2

Phase C

Phase B
Phase A

Source 2

S1 - Line
S1 - Neut

S2 - Line

Control

Power

S2 - Neut

Clk

In

Out

5V

Gnd

Programming

Port

K1 - (Com)

K1 - (NO)

K2 - (Com)

K2 - (NO)

Pretransfer - (Com)

Pretransfer - (NO)

Pretransfer - (NC)

Alarm - (Com)

Alarm - (NO)

Alarm - (NC)

Ear th Ground

Gen Start - (Com)

Gen Start - (NO)

Output Relays

+32 VDC

Source 1 Closed

+32 VDC

Source 2 Closed

+32 VDC

Lockout

+32 VDC

Go To Source 2

+32 VDC

Monitor Mode

Control Inputs

8.0 in.

6.5 in.

3

4

1

2

7

8

5

6

Output
Relays

Control
Inputs

J8

K4 NO
K4 C om

K3 NO
K3 Com

2

1

Rx

Tx

Emergency
Inhibit

Manual
Re-Transfer

J10

3

4

2
1

RS485
Termination

RS-485
MODBUS

A

B

Com

SHD

1

ON

S2
Close

S1
Close

S2

Open

S1

Open

TERMINALS 13 & 14

ATC-300+ Controller - 2 Position Contactor type (In-Phase) - CAT#8160A00G27

ATC-300+ Controller - 3 Position Contactor type (TDN) - CAT#8160A00G28

Page 28 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Step 3: Turn the generator OFF at the generator control panel.

This will prevent unexpected activation of the generator.

Step 4: Connect the Engine Generator Start wires to terminals

13 and 14 on the J-5 connector on the ATC-300+ Con-

ct is CLOSED whenever

troller (Figure 22). This conta

the engine generator is needed, and should be connected
to a generator controller. NEVER connect directly to a
starter solenoid or ignition system. See the Genset man­ufacturer instruction leaflet for recommended wire sizes
and location procedur

es.

Figure 22. Engine Generator Control Connection.

Step 5: Apply

Utility (Source 1) power. If the switch is properly
applied for the system voltage ordered, the display
should work and the Source 1 Available white LED
should light (Figure 23). Using a voltmeter, check for
proper system voltage on Source 1 and load terminals.
Check all phases on a 3-phase switch. Voltage measure­ments should be taken phase to phase and phase to neu­tral.

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Unit Status

ATC-300

Available

Source 1

Source 2

Available

Connected

Load

Connected

Instruction Booklet

Effective: September 2011 Page 29

Engine

Tes t

Help

Lamp

Tes t

TDNE / TDEN

Bypass

Step

Enter

Alarm

Reset

Figure 23. ATC-300+ Logic (Utility Supplying Load).

Step 6: To view the setpoints, press the <Step/Enter> pushbut-

ton and enter the Password.

Note: The factory default Password is 0300. Once all installation and

testing is complete, the Password should be changed by authorized
personnel to a unique Password for the equipment.

After entering the password, press the <Step/Enter>
pushbutton until the VIEW SETPOINTS menu appears.
Select YES. Press the <Step/Enter> pushbutton to
scroll through the setpoints (Figures 24 through 26 and
Table 6).

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 30 Effective: September 2011

Utility - Generator Transfer Switch

Source 1 is available

Source 1 is powering the load

Source 1 becomes unavailable

(or Engine Test, Plant Exercise, Go To Emergency)

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

Close Source 1

(Energize K1)

No

Is Source 1

Available?

TDES timer times out

Send "Engine Start" signal

(Energize Gen Start relay)

Is Source 2

Available?

Ye s

TDNE timer times out

Sends pretransfer signal

TPRE timer times out

(If Source 1 is Available)

Open Source 1

(Energize K2)

Close Source 2

(Energize K2)

No

Ye s

TDEN timer times out

Sends pretransfer signal

TPRE timer times out

Open Source 2

(Energize K1)

Close Source 1

(Energize K1)

Source 1 is powering the load

TDEC timer times out

Remove "Engine Start" signal

(De-energize Gen Start relay)

Source 2 is powering the load

Figure 24. Utility - Generator Transfer Switch.

For more information visit: www.generac.com IB01602078E

Dual Utility Transfer Switch

Source 1 is available

Close Source 1

(Energize K1)

Source 1 is powering the load

Source 1 becomes unavailable

(or Go To Emergency)

Is Source 2

Available?

TDNE timer times out

Open Source 1

(Energize K2)

Close Source 2

(Energize K2)

Source 2 is powering the load

Is Source 1

Available?

TDEN timer times out

Ye s

No

No

Ye s

Open Source 2

(Energize K1)

Close Source 1

(Energize K1)

Source 1 is powering the load

Sends pretransfer signal

TPRE timer times out

(If Source 1 is Available)

Sends pretransfer signal

TPRE timer times out

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 31

Figure 25. Dual Utility Transfer Switch.

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 32 Effective: September 2011

Table 6. Setpoint Possibilities

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

SETPOINT SETPOINT UNITS DESCRIPTION RANGE FACTORY

New Password Four Digits Set New Password 0000 to 9999 0300

TDES Minutes: Seconds Time Delay Engine Start 0 to 120 seconds 0:03

TDNE Minutes: Seconds Time Delay Normal to Emergency 0 to 1800 seconds 0:00

TDEN Minutes: Seconds Time Delay Emergency to Normal 0 to 1800 seconds 5:00

TDEC Minutes: Seconds Time Delay Engine Cool-off 0 to 1800 seconds 5:00

NOM FREQ Hertz Nominal Frequency 50 or 60 Hz As ordered

NOM VOLTS Volts Nominal Voltage 120 to 600 volts As ordered

S1 UV DROP Volts Source 1 Undervoltage Dropout Range: 

S2 UV DROP Volts Source 2 Undervoltage Dropout Range:

S1 UV PICK Volts Source 1 Undervoltage Pickup Range:

S2 UV PICK Volts Source 2 Undervoltage Pickup Range:

S1 OV DROP Volts Source 1 Overvoltage Dropout Range:

S2 OV DROP Volts Source 2 Overvoltage Dropout Range:

S1 OV PICK Volts Source 1 Overvoltage Pickup Range:

S2 OV PICK Volts Source 2 Overvoltage Pickup Range:

S1 UF DROP Hertz Source 1 Underfrequency Dropout Range:

S2 UF DROP Hertz Source 2 Underfrequency Dropout Range:

S1 UF PICK Hertz Source 1 Underfrequency Pickup Range:

S2 UF PICK Hertz Source 2 Underfrequency Pickup Range:

S1 OF DROP Hertz Source 1 Overfrequency Dropout Range:

S2 OF DROP Hertz Source 2 Overfrequency Dropout Range:

S1 OF PICK Hertz Source 1 Overfrequency Pickup Range:

S2 OF PICK Hertz Source 2 Overfrequency Pickup Range:

TDN Minutes: Seconds Time Delay Neutral 0 to 120 seconds 0:00

BAUD RATE Modbus Baud Rate 9600 or 19200 9600

ADDRESS Modbus Address 1 to 247 1

PLANT EXER Days Plant Exerciser Programming OFF, DAILY, 7-DAY, 14-DAY or 28 DAY OFF

PE LOAD XFR Plant Exerciser Load Transfer 0 or 1 (1 = yes) 0

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)

Contactor Style ATS (2-position/3-position)



78 to 97% of Nominal System Voltage



78 to 97% of Nominal System Voltage



(Dropout +2%) to 99% of Nominal System Voltage



(Dropout +2%) to 99% of Nominal System Voltage



105 to 110% of Nominal System Voltage



105 to 110% of Nominal System Voltage



103% to (Dropout -2%) of Nominal System Voltage



103% to (Dropout -2%) of Nominal System Voltage



90 to 97% of Nominal System Frequency



90 to 97% of Nominal System Frequency



(Dropout +1 Hz) to 99% of Nominal System Frequency



(Dropout +1 Hz) to 99% of Nominal System Frequency



103 to 105% of Nominal System Frequency



103 to 105% of Nominal System Frequency



101% to (Dropout -1 Hz) of Nominal System Frequency



101% to (Dropout -1 Hz) of Nominal System Frequency



85%



85%



90%



90%



110%



110%



105%



105%



90%



90%



95%



95%



105%



105%



102%



102%

DEFAULT

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Table 6. Setpoint Possibilities (cont’)

Instruction Booklet

Effective: September 2011 Page 33

SETPOINT SETPOINT UNIT S DESCRIPTION RANGE FACTORY

PE DAY Days Plant Exerciser Day of the Week 1 SUN, 2 MON, 3 TUE, 4 WED, 5 THU, 6 FRI or 7 SAT

PE HOUR Hours Plant Exerciser Hour 0 to 23 0

PE MINUTE Minutes Plant Exerciser Minute 0 to 59 0

TEST MODE Test Mode 0, 1 or 2 (0 = No Load Engine Test, 1 = Load Engine Test, 2 =

TER Hours: Minutes Engine run test time 0 min to 600 min 5:00

TPRE Minutes: Seconds Pretransfer delay timer 0 sec to 120 sec 0:00

PHASES Three phase or single phase 1 or 3 AS ORDERED

VOLT UNBAL Volts Voltage Unbalanced 0 or 1 (1 = Enabled) 1

UNBAL DROP % Percent Percent for Unbalanced Voltage Dropout 5 to 20% of Phase to Phase Voltage Unbalance 20%

UNBAL PICK % Percent Percent for Unbalanced Voltage Pickup Dropout minus (UNBAL DROP % -2) to 3% 10%

UNBAL DELAY Seconds Unbalanced Delay Timer 10 to 30 0:20

TDEF Seconds Time Delay Emergency Fail Timer 0 sec to 6 sec 6

IN-PHASE Hertz In-Phase Transition 0 or 1 (1=Enabled) 1

IP FREQ DIFF Hertz In-phase Transition Frequency Difference 0.0 Hz to 3.0 Hz 1.0

SYNC TIME Minutes In-phase Transition Synchronization Timer 1 min to 60 min 5

PHASE REV Phase Reversal OFF, ABC, or CBA OFF

DST ADJUST Day Light Savings 0 or 1 (1=Enabled) 1

MAN RETRAN Manual Retransfer 0 or 1 (1=Enabled) 0

LANGUAGE Selected Language English, French, or Spanish English

CHANGE TIME/DATE? Set Time and Date

Hours Set Hour 0 to 23 Eastern Standard

MINUTES Set Minute 0 to 59 Eastern Standard

WEEKDAY Set Weekday SUN, MON, TUE, WED, THU, FRI or SAT Eastern Standard

MONTH Set Month JAN or 01 Eastern Standard

DAY Set Day 1 to 31 Eastern Standard

YEAR Set Year Current Year Eastern Standard

RESET 
SYSTEM COUNTERS?

RESET ALL? Resets all System Counters Yes or No No

RESET 
ENGINE RUN?

RESET
S1 CONN

RESET
S2 CONN

RESET
S1 AVAIL

RESET 
S2 AVAIL

RESET
LOAD ENERG

RESET
TRANSFERS

SAVE 
SETPOINTS?

Hours Resets ENGINE RUN Counter 0 to 9999 XXXX

Hours Resets S1 CONN Counter 0 to 9999 XXXX

Hours Resets S2 CONN Counter 0 to 9999 XXXX

Hours Resets S1 AVAIL Counter 0 to 9999 XXXX

Hours Resets S2 AVAIL Counter 0 to 9999 XXXX

Hours Resets LOAD ENERG Counter 0 to 9999 XXXX

Cycles (Counts) Resets TRANSFERS Counter 0 to 9999 XXXX

Save Changed Setpoints Yes or No Yes

Disabled)

Yes or No No

DEFAULT

0

Time

Time

Time

Time

Time

Time

See tables in the appendix for Voltage and Frequency Pickup and Dropout settings.

IB01602078E For more information visit: www.generac.com

Instruction Booklet

ATC-300

Source 1

Source 2

Available

Available

Connected

Connected

Load

Unit Status

Alarm
Reset

Engine

Test

Lamp

Test

Help

Step

Enter

Bypass

TDNE / TDEN

ALARM RESET

DECREASE

ENTER

INCREASE

STEP

BYPASS

TDNE/TDEN

LAMP TEST

ENGINE

TEST

HELP

Page 34 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Step 7: To change or add a setpoint, select Yes when the

“Change Setpoints” message appears on the screen.
Use the <Step/Enter> pushbutton to step through the
setpoints.

Use the <Increase> and <Decrease> pushbuttons to
change the setpoint.

When finished scrolling through and changing the desired

tpoints, answer Yes when the “Save Setpoints?” ques-

se
tion appears on the screen. The display will return to the

fault screen.

de

WARNING

THE GENERATOR SHOULD BE MANUALLY STARTED AND THE
OUTPUT CHECKED AND VERIFIED BEFORE PROCEEDING TO STEP

8. IF IMPROPER VOLTAGE/FREQUENCY IS APPLIED TO THE LOAD,
THE ATS MAY BE DAMAGED.

Step 8: Manually start the engine generator at the generator con-

Step 9: Initiate a Load Te

troller. Check that the generator is running and the

ce 2 Available amber LED is lit. Press the <Step/

Sour

Enter> pushbutton, step through the phase voltages,
frequency, and message display. If the source message
indicates that the source is Good, shut down the genera­tor and place the Genset controller in the Auto-operating
position. If

the message indicates a problem with the
source, the setpoints should be reviewed and the genera­tor checked for proper voltage and frequency output.

st from the front panel of the ATC­300+ (Figure 28). This may be done by setting the
engine test setpoint to:

1 Load Test



then saving the setpoints. Once the engine test setpoint
has been cha

nged and saved, press the <Engine Test>
pushbutton twice. The generator should start, the ATS
should transfer and run on the generator for the set test
interval, then proceed to a TDEN countdown and return
to Source 1. While the ATS is connected to Source 2,
use a voltmeter to check for correct system voltage on
the load terminals of the ATS. Check all phases on a 3­phase system. Voltage measurements should be taken
phase to phase and phase to neutral. A load test will
cause a momentary power outage during transfer.

Figure 26. ATC-300+ Pushbuttons.

For more information visit: www.generac.com IB01602078E

ATC-300

Source 1

Source 2

Available

Available

Connected

Connected

Load

Unit Status

Alarm
Reset

Engine

Test

Lamp

Test

Help

Step

Enter

Bypass

TDNE / TDEN

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Instruction Booklet

Effective: September 2011 Page 35

Figure 27. ATC-300+ Logic.

Step 10: ATC3 Controlled ATS Power Failure Test - Initiate a

Load Test by simulating an actual power failure.

1. This should be done by opening the upstream
ker or fused disconnect switch.

brea

2. The generator should start and the ATS should
transfer

to Source 2.

3. After transfer, close the upstream breaker, or close
the Source

1 Control Circuit Fused Disconnect. The
TDEN timer should begin counting, and, when com­plete, the ATS should transfer to Source 1. The
TDEC should

time out and shut the Source 2 power

unit down.

NOTICE

WHILE PERFORMING TESTING, IF AN UNDESIRED OR UNDOCU­MENTED RESULT OCCURS, CONTACT YOUR GENERAC REPRESEN­TATIVE.

IB01602078E For more information visit: www.genarac.com

Instruction Booklet

Page 36 Effective: September 2011

Appendix A: Pickup / Dropout Tables

UNDERVOLTAGE PICKUP / DROPOUT TABLE

PERCENTAGE VOLTAGE

120 208 220 240 380 415 480 600

97 116 202 213 233 369 403 466 582

96 115 200 211 230 365 398 461 576

95 114 198 209 228 361 394 456 570

94 113 196 207 226 357 390 451 564

93 112 193 205 223 353 386 446 558

92 110 191 202 221 350 382 442 552

91 109 189 200 218 346 378 437 546

90 108 187 198 216 342 374 432 540 Pickup

89 107 185 196 214 338 369 427 534

88 106 183 194 211 334 365 422 528

87 104 181 191 209 331 361 418 522

86 103 179 189 206 327 357 413 516

85 102 177 187 204 323 353 408 510 Dropout

84 101 175 185 202 319 349 403 504

83 100 173 183 199 315 344 398 498

82 98 171 180 197 312 340 394 492

81 97 168 178 194 308 336 389 486

80 96 166 176 192 304 332 384 480

79 95 164 174 190 300 328 379 474

78 94 162 172 187 296 324 374 468

77 92 160 169 185 293 320 370 462

76 91 158 167 182 289 315 365 456

75 90 156 165 180 285 311 360 450

74 89 154 163 178 281 307 355 444

73 88 152 161 175 277 303 350 438

72 86 150 158 173 274 299 346 432

71 85 148 156 170 270 295 341 426

70 84 146 154 168 266 291 336 420

69 83 144 152 166 262 286 331 414

68 82 141 150 163 258 282 326 408

67 80 139 147 161 255 278 322 402

66 79 137 145 158 251 274 317 396

65 78 135 143 156 247 270 312 390

64 77 133 141 154 243 266 307 384

63 76 131 139 151 239 261 302

62 74 129 136 149 236 257 298 372

61 73 127 134 146 232 253 293 366

60 72 125 132 144 228 249 288 360

59 71 123 130 142 224 245 283 354

58 70 121 128 139 220 241 278 348

57 68 119 125 137 217 237 274 342

56 67 116 123 134 213 232 269 336

55 66 114 121 132 209 228 264 330

54 65 112 119 130 205 224 259 324

53 64 110 117 127 201 220 254 318

52 62 108 114 125 198 216 250 312

51 61 106 112 122 194 212 245 306

50 60 104 110 120 190 208 240 300

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

378

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

OVERVOLTAGE PICKUP / DROPOUT TABLE

PERCENTAGE VOLTAGE

120 208 220 240 380 415 480 600

120 144 250 264 288 456 498 576 720

119 143 248 262 286 452 494 571 714

118 142 245 260 283 448 490 566 708

117 140 243 257 281 445 486 562 702

116 139 241 255 278 441 481 557 696

115 138 239 253 276 437 477 552 690

114 137 237 251 274 433 473 547 684

113 136 235 249 271 429 469 542 678

112 134 233 246 269 426 465 538 672

111 133 231 244 266 422 461 533 666

110 132 229 242 264 418 457 528 660 Dropout

109 131 227 240 262 414 452 523 654

108 130 225 238 259 410 448 518 648

107 128 223 235 257 407 444 514 642

106 127 220 233 254 403 440 509 636

105 126 218 231 252 399 436 504 630 Pickup

Instruction Booklet

Effective: September 2011 Page 37

UNDERFREQUENCY PICKUP / DROPOUT TABLE

PERCENTAGE FREQUENCY

50 60

97 49 58

96 48 58

95 48 57 Pickup

94 47 56

93 47 56

92 46 55

91 46 55

90 45 54 Dropout

OVERFREQUENCY P ICKUP / DROPOUT T ABLE

PERCENTAGE FREQUENCY

50 60

110 55 66

109 55 65

108 54 65

107 54 64

106 53 64

105 53 63 Dropout

10

4 52 62

103 52 62

102 51 61 Pickup

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Page 38 Effective: September 2011

Notes:

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

For more information visit: www.generac.com IB01602078E

40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch

Notes:

Instruction Booklet

Effective: September 2011 Page 39

IB01602078E For more information visit: www.generac.com

Instruction Booklet

Generac Power Systems, Inc.
S45 W29290 Hwy. 59
Waukasha, WI 53189
1-888-GENERAC (1-888-436-3722)

generac.com

Page 40 Effective: September 2011

40-400A (480/600Vac) ATC-300+ 3-Postion

Contactor Based Transfer Switch

This instruction booklet is published solely for information pur­poses and should not be considered a

ll-inclusive. If further infor-

mation is required, you should consult Generac.

Sale of the product(s) shown in this literature is subject to terms
and conditions outlined in appropriate Generac selling policies or
other contractual agr

eements between the parties. This literature
is not intended to and does not enlarge or add to any such con­tract. The sole source governing the rights and r

emedies of any
purchaser of this equipment is the contract between the pur­chaser and Generac.

NO WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING WAR­RANTIES OF FITNESS FOR A PARTICULAR PURPOSE OR MER­CHANTABILITY, OR WARRANTIES

ARISING FROM COURSE OF
DEALING OR USAGE OF TRADE, ARE MADE REGARDING THE
INFORMATION, RECOMMENDATIONS AND DESCRIPTIONS
CONTAINED HEREIN.

In no event will Generac be responsible t

o the purchaser or user
in contract, in tort (including negligence), strict liability or other­wise for any special, indirect, incidental or consequential damage
or loss whatsoeve

r, including but not limited to damage or loss of
use of equipment, plant or power system, cost of capital, loss of
power, additional expenses in the use of existing power facilities,
or claims against the purchaser or user by its customers resulting
from the use of the information, recommendations and descrip­tion contained herein.

CSA is a registered trademark of the Canadian Standards Associ­ation. National Electrical Code and NEC ar

e registered trademarks
of the National Fire Protection Association, Quincy, Mass. NEMA
is the registered trademark and service mark of the National Elec­trical Manufacturers Association.

Uniform Building Code (UBC) is
a trademark of the International Conference of Building Officials
(ICBO). UL is a federally registered trademark of the Underwriters
Laboratories Inc.

© 2011 Generac Power Systems, Inc.
All Rights Reserved
Printed in USA

Publication No. IB01602078E/TBG00610
September 2011