Model: 277-240AT
Rev 022113
Please contact Customer Support at 1-800-24VOLTS for further information.
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the
United States and in other countries throughout the world.

Nextek Auto Transformer
Model 277-240AT
Installation Manual
ABOUT NEXTEK POWER SYSTEMS
1.0
SAFETY
2.0
STANDARDS & REQUIREMENTS
3.0
PERSONNEL QUALIFICATIONS
4.0
INSTALLATION QUALIFICATIONS
5.0
PRODUCT SPECIFICATIONS
6.0
CAUTIONS AND WARNINGS
7.0 INSTALLATION PROCEDURE
7.1 Preparing The Auto-Transformer For Mounting
7.2 Mounting The Auto-Transformer
7.3 Wiring The Auto-Transformer
8.0
TROUBLESHOOTING
5
7
8
9
9
5
5
3
4
11
11
13
For more information:
2
Nextek Power Systems
461 Burroughs Street
Detroit, Michigan 48202
Tel: 313-887-1321
Toll free: 1 (877) 24-VOLTS
Fax: 313-887-9433 www.nextekpower.com
info@nextekpower.com
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer
ABOUT NEXTEK POWER SYSTEMS
Installation Manual
Model 277-240AT
Nextek Power Systems AC/DC integration technology represents a breakthrough in onsite electrical management, combining the availability of AC power with the quality and efficiency of a DC supply.
NEXTEK PRODUCT BENEFITS
•
•
Easy conversion of AC lighting fixtures to DC-powered units
Easy conversion of AC grid power into DC power for commercial building applications
•
•
Highly efficient management of peak loads
Future-proof lighting and other systems to be developed
• Nextek Power Systems Direct Coupling® Technology, directly connects clean power generated at a building to its electronic loads inside cutting down on overall power consumption, boosts electricity generated and stored on-site, and delivers a robust renewable energy ready network.
DISCLAIMER
Nextek Power Systems has made every reasonable effort to ensure the accuracy of the information in this catalog. Nextek Power Systems does not guarantee that the information is error free, nor do we make any other representation, warranty or guarantee that the information is accurate, correct, reliable or current. Nextek Power
Systems, Inc. reserves the right to make any adjustments to the information contained herein at any time without notice. The specifications in this catalog are for reference purposes only and are subject to change without notice. Consult Nextek Power Systems for the latest design specifications. All trademarks are either the exclusive property of
Nextek Power Systems, Inc. or other companies. Copyright © 2013-2014 by Nextek
Power Systems, Inc. in the United States and other countries throughout the world.
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
3

Nextek Auto Transformer
Model 277-240AT
1.0
SAFETY
Installation Manual
1.1 SAVE THESE INSTRUCTIONS– This manual contains important safety and operating instructions for the Nextek Auto-Transformer, Model 277–240AT.
The following symbols are used throughout this manual to indicate potentially dangerous conditions or mark important safety instructions:
DANGER:
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING
:
Indicates a potentially dangerous condition. Use extreme caution when performing this task.
CAUTION
:
Indicates a critical procedure for safe and proper operation of the controller.
NOTE
:
Indicates a procedure or function that is important for the safe and proper operation of the controller.
1.2 Before using the Model 277–240AT, read all instructions and cautionary markings.
1.3 Electrical hazards are probably the most common hazards throughout the industry. Virtually all workplaces have electrical installations and use electricity.
1.4 It is very important that all industry employees be familiar with electrical hazards and know how to protect themselves when working on, near, or with electricity.
In most cases, industry electrical and electronic equipment is designed for both maximum safety and efficiency. However, potentially hazardous conditions such as inadvertent contact with hazardous voltages may exist while performing servicing and maintenance, handling materials, or cleaning.
1.5 The improper use of electrical extension cords and portable electrical equipment can result in hazardous exposure.
1.6
WARNING - RISK OF ELECTRICAL SHOCK
1.7
DANGER – TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, CAREFULLY FOLLOW THESE INSTRUCTIONS
1.7.1 Mount the Model 277–240AT indoors. Prevent exposure to the elements and do not allow water to enter the unit.
4 Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer Installation Manual
Model 277-240AT
2.0
STANDARDS AND REQUIREMENTS
2.0
STANDARDS AND REQUIREMENTS
2.1 All AC cable types must meet all local and national codes.
2.2 Shut off all AC breakers before installing any unit into the field.
2.3 Torque all the Auto-Transformer ground terminals to 35 inch-pounds (4NM).
2.4 AC Wiring to Auto-Transformer:
2.4.1 Use a minimum of 12 AWG, 3 conductor cables to reduce losses and ensure high performance.
2.4.2 Copper wiring must be rated at 60°C or higher.
2.4.3 The Auto-Transformer must be protected by a circuit breaker.
3.0
PERSONNEL QUALIFICATIONS
3.1 Installation work and electrical wiring of permanently-connected power units must be performed only by qualified service personnel in accordance with all applicable codes and standards, including fire-rated construction.
4.0
INSTALLATION QUALIFICATIONS
4.1 Every work environment should provide a safe place for every employee, which includes protecting the employee from electrical hazards such as fault currents to ground.
4.2 When an electrical ground fault occurs, the current flows through the path having minimum impedance to ground. It is imperative that an employee does not inadvertently become the conductor of the current.
4.3 Two approved methods of protecting the worker from a ground fault, in addition to other requirements for equipment-grounding conductors, are:
4.3.1 Use of ground fault circuit interrupters (GFCI)
4.3.2 An assured equipment grounding conductor program
4.4 Installers should be advised:
4.4.1 These installation instructions are for use by qualified personnel only.
4.4.2 The equipment contains AC voltages.
NOTE:
Installers must reference the National Electric Code to ensure proper system wiring and grounding compliance. In addition, all state and federal
Occupational Safety and Health Administration (OSHA) guidelines and regulations must be followed.
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
5
Rev. 022113

Nextek Auto Transformer
Model 277-240AT
4.0
GENERAL REQUIREMENTS
Installation Manual
NOTE:
INSTALLERS MUST REFERENCE THE SPECIFIC SITE SCOPE AND
PROJECT DRAWINGS FOR ADDITIONAL INFORMATION AND
CONSIDERATIONS, INCLUDING THE SYSTEM LAYOUT AND ANY RELATED
ELECTRICAL DRAWINGS.
4.5 Tools
4.5.1 Standard construction and electrical tools along with basic electrical safety and testing instruments are required for the installation of the combiner box. In addition to this, installation requires the following:
4.5.1.1 Phillips Screwdriver
4.5.1.2 Torque Wrench
4.5.1.3 Wire Strippers
6 Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer Installation Manual
5.0
PRODUCT SPECIFICATIONS
COMPLIANCE
• UL1012 – Power Units Other Than Class 2
• RoHS – Compliant (Pending)
• Transformer meets UL 506 and CSA C22.2 No. 66
MECHANICAL
Weight
5.0 pounds
Mounting Orientation
Flat vertical surface using 4 screws
Thermal Switch
Shuts off operation at 120°C at transformer
Operational Environmental Limits
Temperature Range 0°C – 50°C
Temperature Rise at Rated Current: 54°C
Humidity: 90% RH non-condensing
Storage Environmental Limits
Temperature Range -40°C – 120°C
Humidity: 90% RH non-condensing (transport and storage in protective container)
Construction
Made of 16 gauge steel
Meets NEMA/EEMAC Type 1 requirements
ELECTRICAL
Input Power
277 VAC
Rated Primary Current: 7.3 A
Rated Frequency: 60 Hz
Output
240 VAC
2 KVA
Efficiency
Quiescent Power = .78W
99.2% @ 277 VAC input; 1600W output
Model 277-240AT
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
7
Rev. 022113

Nextek Auto Transformer
Model 277-240AT
6.0
CAUTIONS AND WARNINGS
Installation Manual
6.1 The Nextek Auto-Transformer connection should only be performed by trained service personnel.
6.2 Follow installation procedure to install and to power up the system.
6.3 The Nextek Auto-Transformer is designed to keep the temperature of its surface from rising to more than 120°C.
6.4 Treat any conductors and parts of electric equipment as energized that have been de-energized, but have not been properly locked or tagged out and tested to a zero energy state.
LOCKOUT/TAGOUT SHOULD ALWAYS BE USED.
6.5 AC connections are made inside the Nextek Auto-Transformer using wire connectors.
6.6 The Nextek Auto-Transformer does not come with the AC power cord. The AC power cord must be a three 12 AWG conductor cable.
Refer to Table 6.1 for list of acceptable equivalent cords
Basic Cord Type Other Suitable Types
TS TST
SP-2 SPE-2, SPT-2
SP-3 SPE-3, SPT-3
SV SVE, SVO, SVOO, SVT, SVTO, SVTOO
SJ SJE, SJO, SJOO, SJT, SJTO, SJTOO
SE SE, SO, SOO, ST, STO, STOO
Table 6.1 Suitable Cord Types
6.7 There are no operator adjustable voltage selectors in this system.
8 Copyright 2012 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer
7.0
INSTALLATION PROCEDURE
Installation Manual
Model 277-240AT
7.1 Preparing The Auto-Transformer For Mounting
7.1.1 Be sure to turn off all main power before starting this project, using the
Lock Out/Tag Out method. Refer to the facility electrical drawings to identify the mounting locations and any specific electrical location requirements or special instructions. You must mount the autotransformer in a position/ location where it is easily accessible.
7.1.2 Enclosed in the shipping container are:
7.1.2.1 Transformer housing
7.1.2.2 Ground kit & wire connectors (right)
7.1.3 Additional material required for mounting (not included)
7.1.3.1 Four Hex Flange Head (Lag Screws)
1/4”x 1-1/2” long.
7.1.3.2 The input power cord must be a three
12 AWG conductor cable.
7.1.3.3 The output power cord must be a three
12 AWG conductor cable.
7.1.4 Removing the front panel.
7.1.4.1 Loosen the four front screws of the enclosure.
7.1.4.2 Remove the front panel.
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
9

Nextek Auto Transformer
Model 277-240AT
7.0
INSTALLATION PROCEDURE
Installation Manual
7.1.5 Grounding kit installation instructions:
7.1.5.1 Drill a 7/32” hole in the enclosure at the top of the enclosure.
7.1.5.2 Remove paint where the grounding connector will contact the enclosure to insure electrical continuity.
7.1.5.3 Install the grounding connector with the bolt, star washer and hex nut provided.
10 Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer Installation Manual
7.0
INSTALLATION PROCEDURE
7.2 Mounting The Auto-Transformer
7.2.1 The auto-transformer is designed to be mounted to plywood.
7.2.2 Use four hex flange head (Lag Screws) 1/4”x 1-
1/2” long to secure the auto-transformer using all four holes inside back side of the enclosure, making sure the unit is straight and level.
Model 277-240AT
7.3 Wiring The Auto-Transformer
7.3.1
Turn off power before installing or removing any connectors
7.3.2 Strip wires 5/16”
7.3.3 Cable Insertion into enclosure
7.3.3.1 Using the side punch-outs, insert the input and output cables through the holes using the appropriate sized conduit.
7.3.4 Connection
7.3.4.1 Hold stripped wires together with ends even and align any frayed strands
7.3.4.2 Push wires into connector and screw on until two twists are visible in wires
7.3.4.3 Input voltage (277 VAC)
7.3.4.3.1 L-1 Common tied to red wire on the auto-transformer
7.3.4.3.2 L-2 Feed tied to black wire on the auto-transformer
7.3.4.3.3 N Ground tied to chassis utilizing the grounding kit
7.3.4.4 Output voltage (240 VAC)
7.3.4.4.1 L-3 Common tied to red wire on the auto-transformer
7.3.4.4.2 L-4 Feed tied to brown wire on the auto-transformer
7.3.4.4.3 N Ground tied to chassis utilizing the grounding kit
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
11
Rev. 022113

Nextek Auto Transformer
Model 277-240AT
7.0
INSTALLATION PROCEDURE
Installation Manual
7.3.5 Installing the front panel
7.3.5.1 Place the panel over the four screws
7.3.5.2 Tighten the screws down.
12 Copyright 2012 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
Rev. 022113

Nextek Auto Transformer
8.0
TROUBLESHOOTING
Installation Manual
Model 277-240AT
FAULT
No Power at the Ouput
Device
PROCEDURE
• Make sure the power circuit feeding the device is turned on.
• Make sure the circuit is wired properly
• Safely and cautiously check to make sure the device has not overheated from an excessive current draw.
• If it has, you will need to turn off the output to allow the device to cool.
• The output power draw will need to be reduced to prevent overheating
Copyright 2013-2014 all rights reserved by Nextek Power Systems, Inc. in the United States and in other countries throughout the world.
13
Rev. 022113

For more information: Nextek Power Systems
461 Burroughs Street
Detroit, Michigan 48202 www.nextekpower.com
Tel: 313-887-1321
Toll free: 1 (877) 24-VOLTS
Fax: 313-887-9433 info@nextekpower.com