USACE / NAVFAC / AFCESA / NASA UFGS-26 29 23 (April 2006)
------------------------------
Preparing Activity: NAVFAC Replacing without change
UFGS-16261 (August 2004)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 26 29 23
VARIABLE FREQUENCY DRIVE SYSTEMS UNDER 600 VOLTS
04/06
NOTE: This guide specification covers the requirements for variable frequency
drive for motors rated up to 575 volts, for use on electric power systems of
600 volts or less, 50/60 hertz.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
NOTE: Pulse width modulated (PWM) is the predominant type of variable frequency
drive (VFD). Other VFD types include current source inverter (CSI), voltage
source inverter (VSI), and flux vector drive (FVD). For a description of each
type of VFD, basic information on the principles of operation of VFD's, guidance
of the proper application of VFD's, and installation guidelines, refer to Appendix
D of MIL-HBDK-1003/3, Heating, Ventilating, Air Conditioning, and Dehumidification
Systems.
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)IEEE C62.41.1(2002) IEEE Guide on the Surges Environment in Low-Voltage (1000 V and Less) AC Power CircuitsIEEE C62.41.2(2002) IEEE Recommended Practice on Characterization of Surges in Low-Voltage (1000 V and Less) AC Power CircuitsIEEE Std 519(1992; Errata 2004) Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems][NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)NEMA 250(2003) Enclosures for Electrical Equipment (1000 Volts Maximum)NEMA ICS 1(2000; R 2005; R 2008) Standard for Industrial Control and Systems General RequirementsNEMA ICS 3.1(1997; R 2003) Industrial Control and Systems: Handling, Storage and Installation Guide for AC General-Purpose Medium Voltage Contactors and Class E Controllers, 50 and 60 HertzNEMA ICS 6(1993; R 2006) Standard for Industrial Controls and Systems EnclosuresNEMA ICS 7(2006) Industrial Control and Systems: Adjustable-Speed Drives][NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)NFPA 70(2007; AMD 1 2008) National Electrical Code - 2008 Edition][U.S. DEPARTMENT OF DEFENSE (DOD)MIL-STD-461(Rev F) Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment][U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)47 CFR 15Radio Frequency Devices][UNDERWRITERS LABORATORIES (UL)UL 489(2002; Rev thru Jun 2006) Standard for Molded-Case Circuit Breakers, Molded-Case Switches and Circuit-Breaker EnclosuresUL 508C(2002; Rev thru Feb 2008) Power Conversion Equipment]1.2 RELATED REQUIREMENTS
Section 26 00 00.00 20 BASIC ELECTRICAL MATERIALS AND METHODS, and Section 26 20 00 DISTRIBUTION WIRING SYSTEM
apply to this section with additions and modifications specified herein.
1.3 SYSTEM DESCRIPTION
1.3.1 Performance Requirements
1.3.1.1 Electromagnetic Interference Suppression
Computing devices, as defined by 47 CFR 15, MIL-STD-461 rules and regulations, shall be certified to comply with
the requirements for class A computing devices and labeled as set forth in part 15.
1.3.1.2 Electromechanical and Electrical Components
Electrical and electromechanical components of the Variable Frequency Drive (VFD) shall not cause electromagnetic
interference to adjacent electrical or electromechanical equipment while in operation.
1.3.2 Electrical Requirements
1.3.2.1 Power Line Surge Protection
IEEE C62.41.1 and IEEE C62.41.2, IEEE Std 519 Control panel shall have surge protection, included within the
panel to protect the unit from damaging transient voltage surges. Surge arrestor shall be mounted near the incoming
power source and properly wired to all three phases and ground. Fuses shall not be used for surge protection.
1.3.2.2 Sensor and Control Wiring Surge Protection
I/O functions as specified shall be protected against surges induced on control and sensor wiring installed outdoors
and as shown. The inputs and outputs shall be tested in both normal mode and common mode using the following
two waveforms:
a. A 10 microsecond by 1000 microsecond waveform with a peak voltage of 1500 volts and a peak
current of 60 amperes.
b. An 8 microsecond by 20 microsecond waveform with a peak voltage of 1000 volts and a peak
current of 500 amperes.
1.4 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are [for Contractor Quality Control approval.][for information only. When used, a designation following the
"G" designation identifies the office that will review the submittal for the Government.] The following shall
be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Schematic diagrams[; G][; G, [_____]]
Interconnecting diagrams[; G][; G, [_____]]
Installation drawings[; G][; G, [_____]]
Submit drawings for government approval prior to equipment construction or integration. Modifications
to original drawings made during installation shall be immediately recorded for inclusion into
the as-built drawings.
SD-03 Product Data
Variable frequency drives[; G][; G, [_____]]
Wires and cables
Equipment schedule
Include data indicating compatibility with motors being driven.
SD-06 Test Reports
VFD Test
Performance Verification Tests
Endurance Test
SD-08 Manufacturer's Instructions
Installation instructions
SD-09 Manufacturer's Field Reports
VFD Factory Test Plan[; G][; G, [_____]]
Factory test results
SD-10 Operation and Maintenance Data
Variable frequency drives, Data Package 4
Submit in accordance with Section 01 78 23 OPERATION AND MAITNENANCE DATA. Provide service
and maintenance information including preventive maintenance, assembly, and disassembly procedures.
Include electrical drawings from electrical general sections. Submit additional information
necessary to provide complete operation, repair, and maintenance information, detailed to the
smallest replaceable unit. Include copies of as-built submittals. Provide routine preventative
maintenance instructions, and equipment required. Provide instructions on how to modify program
settings, and modify the control program. Provide instructions on drive adjustment, trouble-shooting,
and configuration. Provide instructions on process tuning and system calibration.
1.5 QUALITY ASSURANCE
1.5.1 Schematic Diagrams
Show circuits and device elements for each replaceable module. Schematic diagrams of printed circuit boards
are permitted to group functional assemblies as devices, provided that sufficient information is provided for
government maintenance personnel to verify proper operation of the functional assemblies.
1.5.2 Interconnecting Diagrams
Show interconnections between equipment assemblies, and external interfaces, including power and signal conductors.
Include for enclosures and external devices.
1.5.3 Installation Drawings
Show floor plan of each site, with V.F.D.'s and motors indicated. Indicate ventilation requirements, adequate
clearances, and cable routes.
1.5.4 Equipment Schedule
Provide schedule of equipment supplied. Schedule shall provide a cross reference between manufacturer data and
identifiers indicated in shop drawings. Schedule shall include the total quantity of each item of equipment
supplied. For complete assemblies, such as VFD's, provide the serial numbers of each assembly, and a sub-schedule
of components within the assembly. Provide recommended spare parts listing for each assembly or component.
1.5.5 Installation instructions
Provide installation instructions issued by the manufacturer of the equipment, including notes and recommendations,
prior to shipment to the site. Provide operation instructions prior to acceptance testing.
1.5.6 Factory Test Results
Document test results and submit to government within 7 working days after completion of test.
1.6 DELIVERY AND STORAGE
Equipment delivered and placed in storage shall be stored with protection from the weather, humidity and temperature
variations, dirt and dust, or other contaminants.
1.7 WARRANTY
The complete system shall be warranted by the manufacturer for a period of one year, or the contracted period
of any extended warrantee agreed upon by the contractor and the Government, after successful completion of the
acceptance test. Any component failing to perform its function as specified and documented shall be repaired
or replaced by the contractor at no additional cost to the Government. Items repaired or replaced shall be warranted
for an additional period of at least one year from the date that it becomes functional again, as specified in
the FAR CLAUSE 52.246-21.
1.8 MAINTENANCE
1.8.1 Spare Parts
Manufacturers provide spare parts in accordance with recommended spare parts list.
1.8.2 Maintenance Support
During the warranty period, the Contractor shall provide on-site, on-call maintenance services by Contractor's
personnel on the following basis: The service shall be on a per-call basis with 36 hour response. Contractor
shall support the maintenanc e of all hardware and software of the system. Various personnel of different expertise
shall be sent on-site depending on the nature of the maintenance service required. Costs shall include travel,
local transportation, living expenses, and labor rates of the service personnel while responding to the service
request. The provisions of this Section are not in lieu of, nor relieve the Contractor of, warranty responsibilities
covered in this specification. Should the result of the service request be the uncovering of a system defect
covered under the warranty provisions, all costs for the call, including the labor necessary to identify the
defect, shall be borne by the Contractor.
PART 2 PRODUCTS
2.1 VARIABLE FREQUENCY DRIVES (VFD)
Provide frequency drive to control the speed of induction motor(s). The VFD shall include the following minimum
functions, features and ratings.
a. Input circuit breaker per UL 489 with a minimum of 10,000 amps symmetrical interrupting
capacity and door interlocked external operator.
b. A converter stage per UL 508C shall change fixed voltage, fixed frequency, ac line power
to a fixed dc voltage. The converter shall utilize a full wave bridge design incorporating diode
rectifiers. Silicon Controlled Rectifiers (SCR) are not acceptable. The converter shall be
insensitive to three phase rotation of the ac line and shall not cause displacement power factor
of less than .95 lagging under any speed and load condition.
c. An inverter stage shall change fixed dc voltage to variable frequency, variable voltage,
ac for application to a standard NEMA design B squirrel cage motor. The inverter shall be switched
in a manner to produce a sine coded pulse width modulated (PWM) output waveform.
NOTE: If constant torque required modify to 150 percent of rated full load.
d. The VFD shall be capable of supplying 120 percent of rated full load current for one minute
at maximum ambient temperature.
e. The VFD shall be designed to operate from a [_____] volt, + or - 10 percent, three phase,
60 Hz supply, and control motors with a corresponding voltage rating.
f. Acceleration and deceleration time shall be independently adjustable from one second to
60 seconds.
NOTE: Modify this paragraph if constant torque required.
g. Adjustable full-time current limiting shall limit the current to a preset value which shall
not exceed 120 percent of the controller rated current. The current limiting action shall maintain
the V/Hz ratio constant so that variable torque can be maintained. Short time starting override
shall allow starting current to reach 175 percent of controller rated current to maximum starting
torque.
h. The controllers shall be capable of producing an output frequency over the range of 3 Hz
to 60 Hz (20 to one speed range), without low speed cogging. Over frequency protection shall
be included such that a failure in the controller electronic circuitry shall not cause frequency
to exceed 110 percent of the maximum controller output frequency selected.
i. Minimum and maximum output frequency shall be adjustable over the following ranges: 1)
Minimum frequency 3 Hz to 50 percent of maximum selected frequency; 2) Maximum frequency 40
Hz to 60 Hz.
j. The controller efficiency at any speed shall not be less than 96 percent.
k. The controllers shall be capable of being restarted into a motor coasting in the forward
direction without tripping.
l. Protection of power semiconductor components shall be accomplished without the use of fast
acting semiconductor output fuses. Subjecting the controllers to any of the following conditions
shall not result in component failure or the need for fuse replacment:
1. Short circuit at controller output
2. Ground fault at controller output
3. Open circuit at controller output
4. Input undervoltage
5. Input overvoltage
6. Loss of input phase
7. AC line switching transients
8. Instantaneous overload
9. Sustained overload exceeding 115 percent of controller rated current
10. Over temperature
11. Phase reversal
m. Solid state motor overload protection shall be included such that current exceeding an adjustable
threshold shall activate a 60 second timing circuit. Should current remain above the threshold
continuously for the timing period, the controller will automatically shut down.
n. A slip compensation circuit shall be included which will sense changing motor load conditions
and adjust output frequency to provide speed regulation of NEMA B motors to within + / - 0.5
percent of maximum speed without the necessity of a tachometer generator.
o. The VFD shall be factory set for manual restart after the first protective circuit trip
for malfunction (overcurrent,undervoltage, overvoltage or overtemperature) or an interruption
of power. The VFD shall be capable of being set for automatic restart after a selected time
delay. If the drive faults again within a specified time period (adjustable 0-60 seconds), a
manual restart will be required.
p. The VFD shall include external fault reset capability. All the necessary logic to accept
an external fault reset contact shall be included.
q. Provide critical speed lockout circuitry to prevent operating at frequencies with critical
harmonics that cause resonant vibrations. The VFD shall have a minimum of three user selectable
bandwidths.
r. Provide the following operator control and monitoring devices mounted on the front panel
of the VFD:
1. Manual speed potentiometer.
2. Hand-Off-Auto ( HOA ) switch.
3. Power on light.
4. Drive run power light.
5. Local display.
s. Provide properly sized NEMA rated by-pass and isolation contactors to enable operation of
motor in the event of VFD failure. Mechanical and electrical interlocks shall be installed between
the by-pass and isolation contactors. Provide a selector switch and transfer delay timer.
2.2 ENCLOSURES
Provide equipment enclosures conforming to NEMA 250, NEMA ICS 7, NEMA ICS 6.
2.3 WIRES AND CABLES
All wires and cables shall conform to NEMA 250, NEMA ICS 7, NFPA 70.
2.4 NAMEPLATES
Nameplates external to NEMA enclosures shall conform with the requirements of Section 26 00 00.00 20 BASIC ELECTRICAL
MATERIALS AND METHODS. Nameplates internal to enclosures shall be manufacturer's standard, with the exception
that they must be permanent.
2.5 SOURCE QUALITY CONTROL
2.5.1 VFD Factory Test Plan
To ensure quality, each VFD shall be subject to a series of in-plant quality control inspections before approval
for shipment from the manufacturer's facilities. Provide test plans and test reports.
PART 3 EXECUTION
3.1 INSTALLATION
Per NEMA ICS 3.1, install equipment in accordance with the approved manufacturer's printed installation drawings,
instructions, wiring diagrams, and as indicated on project drawings and the approved shop drawings. A field
representative of the drive manufacturer shall supervise the installation of all equipment, and wiring.
3.2 FIELD QUALITY CONTROL
Specified products shall be tested as a system for conformance to specification requirements prior to scheduling
the acceptance tests. Contractor shall conduct performance verification tests in the presence of Government
representative, observing and documenting complete compliance of the system to the specifications. Contractor
shall submit a signed copy of the test results, certifying proper system operation before scheduling tests.
3.2.1 VFD Test
A proposed test plan shall be submitted to the contracting officer at least 28 calendar days prior to proposed
testing for approval. The tests shall conform to NEMA ICS 1, NEMA ICS 7, and all manufacturer's safety regulations.
The Government reserves the right to witness all tests and review any documentation. The contractor shall inform
the Government at least 14 working days prior to the dates of testing. Contractor shall provide video tapes,
if available, of all training provided to the Government for subsequent use in training new personnel. All training
aids, texts, and expendable support material for a self-sufficient presentation shall be provided, the amount
of which to be determined by the contracting officer.
3.2.2 Performance Verification Tests
"Performance Verification Test" plan shall provide the step by step procedure required to establish formal verification
of the performance of the VFD. Compliance with the specification requirements shall be verified by inspections,
review of critical data, demonstrations, and tests. The Government reserves the right to witness all tests,
review data, and request other such additional inspections and repeat tests as necessary to ensure that the system
and provided services conform to the stated requirements. The contractor shall inform the Government 14 calendar
days prior to the date the test is to be conducted.
3.2.3 Endurance Test
Immediately upon completion of the performance verification test, the endurance test shall commence. The system
shall be operated at varying rates for not less than 192 consecutive hours, at an average effectiveness level
of .9998, to demonstrate proper functioning of the complete PCS. Continue the test on a day-to-day basis until
performance standard is met. During the endurance test, the contractor shall not be allowed in the building.
The system shall respond as designed.
3.3 DEMONSTRATION
3.3.1 Training
Coordinate training requirements with the Contracting Officer.
3.3.1.1 Instructions to Government Personnel
Provide the services of competent instructors who will give full instruction to designated personnel in operation,
maintenance, calibration, configuration, and programming of the complete control system. Orient the training
specifically to the system installed. Instructors shall be thoroughly familiar with the subject matter they
are to teach. The Government personnel designated to attend the training will have a high school education or
equivalent. The number of training days of instruction furnished shall be as specified. A training day is defined
as eight hours of instruction, including two 15-minute breaks and excluding lunch time; Monday through Friday.
Provide a training manual for each student at each training phase which describes in detail the material included
in each training program. Provide one additional copy for archiving. Provide equipment and materials required
for classroom training. Provide a list of additional related courses, and offers, noting any courses recommended.
List each training course individually by name, including duration, approximate cost per person, and location
of course. Unused copies of training manuals shall be turned over to the Government at the end of last training
session.
3.3.1.2 Operating Personnel Training Program
Provide one 2 hour training session at the site at a time and place mutually agreeable between the Contractor
and the Government. Provide session to train 4 operation personnel in the functional operations of the system
and the procedures that personnel will follow in system operation. This training shall include:
a. System overview
b. General theory of operation
c. System operation
d. Alarm formats
e. Failure recovery procedures
f. Troubleshooting
3.3.1.3 Engineering/Maintenance Personnel Training
Accomplish the training program as specified. Training shall be conducted on site at a location designated by
the Government. Provide a one day training session to train 4 engineering personnel in the functional operations
of the system. This training shall include:
a. System overview
b. General theory of operation
c. System operation
d. System configuration
e. Alarm formats
f. Failure recovery procedures
g. Troubleshooting and repair
h. Maintenance and calibration
i. System programming and configuration