Emerson Industrial Automation

Control Techniques

HVAC Drive H300

Variable Frequency Drive Specification

PART 1 GENERAL

1.01DESCRIPTION

  1. This specification covers a Variable Frequency Sensorless AC Motor Drive (VFD) foruse on a standard NEMA Design B induction motor with features specific to Building Automation applications.
  2. The VFD manufacturer shall supply the drive and all necessary controls as specified herein.

1.02QUALITY ASSURANCE

  1. The drive products must be designed and manufactured in accordance with the following European harmonized standards:
  • EN 61800-5-1: Adjustable speed electrical power drive systems - safety performance requirements – electrical, thermal and energy.
  • EN 61800-3: Adjustable speed electrical power drive systems – EMC product standard including specific test methods
  • EN 61000-6-2: Electromagnetic Compatibility (EMC). Generic standards. Immunity standard for industrial environments
  • EN 61000-6-4: Electromagnetic Compatibility (EMC). Generic standards. Immunity standard for industrial environments
  • EN 61000-3-2: Electromagnetic compatibility (EMC), Limits. Limits for harmonic current emissions(equipment input current <16 A per phase)
  • EN 61000-3-3:Electromagnetic compatibility (EMC), Limits. Limitation of voltage fluctuations and flicker inlow-voltage supply systems for equipment

with rated current <16 A

  1. Referenced Standards:
  • Institute of Electrical and Electronics Engineers (IEEE)
  • Standard 519-1992, IEEE Guide for Harmonic Content and Control.
  • Underwriter Laboratories
  • UL508C
  • National Electric Manufacturer’s Association (NEMA)
  • ICS 7.0, AC Adjustable Speed Drives
  • IEC 16800 Parts 1 and 2
  1. VFD shall be manufactured in ISO9002 certified facility.
  1. VFD shall be manufactured in accordance with ISO 14001 (Environmental Management Standard)
  1. VFD shall be UL, cUL listed.
  1. VFD shall be CE certified and conform to European Union EMC directives.
  1. VFD shall meet the following vibration test standards: IEC 60068-2-29; 60068-2-64; 60068-2-6

1.03 QUALIFICATIONS

  1. Manufacturer must have a minimum of 25 years of documented experience
    specializing in variable frequency drives.
  1. VFDs manufactured by third party and brand labeled shall not be acceptable.
  1. Manufacturer must be a division of a United States based corporation with corporate headquarters in the United States.

1.04 SUBMITTALS

  1. Shop drawings shall include the following information:
  2. Overall dimensions & weight
  3. Physical layout and enclosure drawings (front and side views)
  4. Conduit entrance locations and requirements
  5. Electrical schematics / Wiring diagrams
  6. Compliance to IEEE 519 with harmonic analysis for a particular installation site including total harmonic voltage distortion and total harmonic current distortion (TDD) when requested.
  1. Product Data: Provide technical data sheets incorporating Electrical and Mechanical product information.
  2. Operation and Maintenance data: Include instructions for starting and operating VFD and describe operating limits, which may result in hazardous or unsafe conditions.

1.05 MANUFACTURERS

  1. Acceptable VFD manufacturers shall be:
  1. Emerson Industrial Automation
  2. Emerson Industrial Automation / Control Techniques

1.06 WARRANTY

  1. The VFD shall be warranted by the manufacturer for 2 years from date of shipment. The manufacturer shall offer extended warrantyfor up to 6 years from date of shipment.

PART 2 PRODUCTS

2.01VARIABLE FREQUENCY AC DRIVES

  1. The VFD shall convert incoming ac power with a fixed frequency into an adjustable voltage and frequency Pulse Width Modulated (PWM) output waveform to control the speed of a three-phase AC motor. The control algorithm shall be digital.
  2. The drive control mode shall be selectable from open loop vector, fixed v/f, quadratic V/Hz, Dynamic V/Hzand Rotor Flux Control (RFC) modes
  3. The VFD shall be packaged as UL Type 1, UL Type 12 or UL Type 3R depending on the schedule.
  4. The VFD shall have been evaluated by UL and be acceptable for mounting in a plenum or other air handling compartment. VFD Manufacturer shall supply copy of the UL plenum evaluation upon request.

2.02 DESCRIPTION

  1. Provide enclosed variable frequency drives suitable for operation at the current, voltage, and horsepower indicated on the schedule. Conform to requirements of NEMA ICS 7.1.

2.03 RATINGS

  1. The VFD must operate, without fault or failure, for the following 3-phase supply voltage range:
  1. 200V units: 200 to 240V +/- 10%
  2. 400V units: 380 to 480V +/- 10%
  3. 575V units: 500 to 575V +/- 10%
  4. 690V units: 500 to 690V +/- 10%
  1. The VFD shall function for an input supply frequency rangebetween 45and 66Hz.
  1. Phase imbalance: The VFD shall function for up to 2% negative phase sequence (equivalent to 3% tolerance of voltage imbalance between phases)
  1. Displacement Power Factor (Cos φ): Greater than 0.97over the entire ranges of operating speed and load.
  1. Operating Ambient Temperature range: -20° C to 50° C (-4° F to 122° F) continuous. Operation at 50° C (122° F) shall be possible with de-rating.
  1. Storage Temperature: -40° C to 50° C (-40° F to 122° F)
  1. Humidity: 0% to 95% non-condensing at 40° C.
  1. Altitude: 0 to 3,300 feet, withoutany de-rating. Above 3,300 feet operation shall be possible with 1% current de-rating for each additional 328 feet.
  1. Minimum Efficiency: 96% at full speed
  1. Overload capability: The full load continuous output current rating of the VFD must meet or exceed that of the motor nameplate full load amp rating. The VFDs shall be able to provide 110% of drive rated current for 60 seconds and 225% of drive rated current as instantaneous overload.
  1. Total Harmonic Distortion (THD) compliance:

Given the information provided by the customer’s electric power single line diagram and distribution transformer data, the VFD manufacturer shall carry out aHarmonic estimationforthe system. The Harmonic estimationreviews the potential for the proposed equipment, and any existing equipment, to meet IEEE 519, latest version, (tables 10.2 and 10.3) recommendations at the Point of Common Coupling (PCC). The result of the Harmonic estimationshall determine if additional power quality improvement measures should be included in the proposal to meet the THD recommendations of IEEE 519. The PCC shall be at the primary side of the main distribution transformer.

  1. VFDs must be rated for a symmetrical short circuit rating of 100 kA RMS
  1. RoHS Compliance:

The drive meets EU directive 2002-95-EC for RoHS compliance.

2.04STANDARD FEATURES

The VFD shall have the following standard built-in features:

  1. Carrier (Switching) Frequency:
  1. The VFD shall be selected for operation at carrier frequencies at or above 3kHz to satisfy the conditions for current, voltage, and horsepower as indicated on the equipment schedule.Higher carrier frequencies shall be possible for quieter operation.
  2. VFD shall have an adjustable carrier frequency with the ability to adjust while the VFD is running. It shall include automatic carrier frequency reduction to reduce tripping in the event of high temperature operation.
  3. The carrier frequency should be selectable from 2 to 16KHz.
  1. InterfaceKeypad / Parameter storage:
  1. All VFDs shall have the same customer interface with a digital display and local controls irrespective of the voltage and horsepower rating. Thekeypad shall have a backlit LCD plain-text display and shall be removableand remote mountable allowing programming, operating, monitoring, and diagnostic capability from both local and remote locations. For fault diagnostics purposes, only alpha-numeric codes are not acceptable.
  2. The keypad shall have Hand-Off-Auto control selections and manual speed control. The speed reference transfer shall be ‘bump-less’ when switching between “Hand” and “Auto” modes. All parameters shall be accessible from the keypad. The keypad shall have “Fault Reset” and “Parameter Help” buttons.
  3. The display shall be in plain text. Alphanumeric codes alone shall not be acceptable.
  4. The keypad shall be configurable in English, Spanish or French.
  5. The drive/keypad combination shall allow customizing up to 20 parameter names based on the application.
  6. Each VFD shall include a compact ‘Smartcard’ parameter copy/storage unit that can be attached and removed with power applied.
  7. In order to reduce programming time, pre-programmed macros shall be configurable using either a ‘Smartcard’ or an ‘SD Smartcard’.
  1. The VFD shall have the provision to accept an external 24Vdc supply to keep the control circuits powered up when the mains supply is removed or lost in order to keep the control electronics and field bus functional all the times.
  1. The VFD shall be able to accelerate/decelerate high inertia loads to desired set points and shall have a flying restart capability to restart coasting loads without any interruption to operation.
  1. Mains Loss Condition:
  1. VFD shall include a selectable power loss ride through functionality that would allow maintaining DC Bus voltage above trip levels during momentary voltage dips or mains loss.
  2. In case of a mains loss and subsequent power recovery, the VFD shall have the ability to restart without manual intervention.
  1. The VFD shall have the ability to automatically reset and restart up to 5 times (programmable)after fault conditions such as overload, over-voltage or loss of input signal. The time between the attempts shall be programmable.
  1. At 460V, 5HP up to 200 HP, the VFD shall have a built-in AC or DC reactor equivalent to 3% of line impedance or else must include an equivalent external line reactor in order to protect from AC line transients & to reduce harmonics.
  1. The VFD shall include an onboard EMC/RFI filter meeting CE and EN61800-3 standard for First Environment restricted level.
  1. The VFD shall be able to sense and flag a ‘loss of load’condition (including conditions such as broken belt or broken coupling). The drive shall be programmable to signal this condition through keypad warning, relay output and via serial communication field bus.
  1. The VFD shall have the capability to preheat the motor windings as may be necessary for humid environments.
  1. The VFD shall have programmable “Sleep” and “Wake” functions built-in that will allow it to be stopped and restarted automatically based on a selectable threshold value of the feedback signal.
  1. The VFD shall have 3 skip frequency bands to prevent continuous operation at speeds that would cause mechanical resonance.
  1. The VFD shall have 2 built-in PID loops that shall work either independently or by closing motor speed control loop. The PID set points shall be accessible from keypad, an analog input or field bus communications. The VFD shall be able to invert the polarity of the reference or feedback signal without the need to rewire the analog inputs. All PID parameters shall be accessible by field bus network.

  1. The VFD shall have a built-in Real-time Clock with a battery back-up of minimum 10 year life span. The battery shall be integral part of the drive
  1. The VFD shall have the following input and outputs:
  1. Analog inputs: The VFD shall have three (2) programmable analog inputs.At least one input shall have an update time of 250 µsec or less when configured as speed reference. There shall be at least two (2) analog inputs that shall be configured as a voltage (+/- 10Vdc) or current (0-20mA, 20-0mA, 4-20mA, 20-4mA) inputs with a ‘Trip on loss of signal’ option available for the 4-20mA & 20-0mA option.
  2. Analog outputs: There shall be a minimum of 2 programmable analog outputs that can be programmed as voltage or current outputs.
  3. Digital Input/Outputs: The drive shall have three (3) programmable digital inputs and three (3) additional terminals that shall be configured as inputs or outputs. Positive or negative logic shall be selectable for the inputs and outputs. It shall also be possible to invert the signal polarity of each of the input or output signal in order to avoid flipping the wiring.
  4. Drive Enable/Secure Disable: The drive shall have an input terminal that shall inhibit the IGBT firing signals when this input is not connected in order to provide additional safety interlock to prevent unintended operation of the motor.
  5. The VFD shall have at least two programmable Form C relay outputs that have a 230Vac, 2A resistive contact rating.
  6. The VFD shall have provisions to accommodate optional additional I/O.
  1. The VFD shall have eight (8) programmable preset speeds.
  1. The VFD shall have eight independently adjustable accel and decel ramps with 1 to 1900 sec adjustable time ramp over the motor base speed range. S-ramp controls shall be built-in to increase the life of the motor and mechanical equipment.

The VFD shall have dynamic V/Hz functionality that optimizes the applied motor voltage based on the energy consumption.

  1. Serial Communications / Field bus options: All VFDs shall have a built-in RS-485 port.
  1. VFD shall have embedded Modbus RTU and BACnet protocols as standardfor building automation systems network communications accessible via a RS-485 communication port.
  2. Optional protocols shall include Ethernet, DeviceNet and Profibus.
  3. Serial communication capabilities shall include setting and saving parameter values, controlling operation such as Start/Stop and speed adjustment and monitoring faults and feedback
  1. VFD shall have DC injection braking capability, to prevent fan “wind milling” at start or stop, adjustable, current limited. Smart speed search capabilities to catch a wind milling motor, is preferred.
  1. Stopping Modes: The VFD shall have multiple stopping modes including coast to stop, ramp stop, and DC injection braking stop. The VFD shall include a dynamic braking transistor across the entire range.
  1. VFD shall retain last 10 faults for diagnostic evaluation. VFD shall include a run time log to record the years, days, hours, and minutes of operation for purpose of maintenance.
  1. VFD shall include programmable electronic thermal overload protection for both the drive and motor. The electronic thermal motor overload shall be approved by UL. VFDs without a UL Listed will not be accepted.
  1. The VFD shall include a fireman’s override input. This mode shall override all other control modes (analog, digital, serial and keypad commands) and the motor shall run at an adjustable preset speed. The keypad shall display ‘Override Mode’ status. Upon removal of the override signal, normal operation shall be resumed.
  1. In order to facilitate user programming, the VFD shall have a built-in PLC functionality with IEC61131-3 software programming capabilities.
  1. The VFD shall have a maximum output frequency of 500Hz in all operating modes.
  1. The VFD should be suitable for installation in a duct handling conditioned air when installed as enclosed types with the Type 1 terminals.

2.05OPTIONAL FEATURES

All optional features shall be UL Listed and shall be packaged together by the VFD manufacturer as a complete assembly with a UL 508 label.

  1. Three Contactor Electronic Bypass shall be provided when indicated by the schedule. VFD and bypass components shall be mounted, fully pre-wired, tested and made available for installation as one UL listed assembly by the drive manufacturer. Bypass shall include the following:
  1. Input, output, and bypass contactors, to disconnect power to the VFD, when the motor is running in the bypass mode.
  2. 120 VAC control transformer, with fused primary and secondary.
  3. Thermal overload relay, to protect the motor while operating in the bypass mode.Circuit breaker or fused disconnect switch, with a pad-lockable through the door handle mechanism.
  4. Control and safety circuit terminal strip.
  5. Drive/Bypass switching, Hand/Off/Auto, and Normal/Test functions via operator touch pad.
  6. Selectable smoke purge, auto transfer to bypass and remote transfer functions.
  7. Pilot LED Indicators for "Power On ", "Drive Fault", “Drive Run”, “Bypass Run”, “OL/Safety Fault”, “Normal/Test”, “Smoke Purge”,“Drive Fault”, “Motor Overload”, “Bypass H-O-A Mode”,, “Safety Open”,. A test mode or push to test button shall be provided.
  8. The digital inputs shall be 24Vdc or optional 115Vac depending on the schedule. All necessary power sources shall be included by the VFD manufacturer.
  9. A customer interlock terminal strip shall be provided in the enclosure for connection of freeze, fire, smoke contacts and external start command. All external safety interlocks shall remain fully functional whether the system is Hand, Auto or Bypass modes.The remote start/stop contact shall operate in VFD and bypass modes.
  10. Dedicated digital input that will transfer motor from VFD mode to bypass mode upon dry contact closure for fireman’s override. Fireman’s override mode remains as above but will also defeat the overload and single-phase protection for bypass and ignore all keypad and digital inputs to the system (run until destruction).
  11. The VFD shall include a “run permissive circuit” that will provide a normally open contact whenever a run command is provided (local or remote start command in VFD or bypass mode). The VFD system (VFD or bypass) shall not operate the motor until it receives a dry contact closure from a damper or valve end-switch. When the VFD system safety interlock (fire detector, freezestat, high static pressure switch, etc.) opens, the motor shall coast to a stop and the run permissive contact shall open, closing the damper or valve.
  12. Class 20 motor overload protection shall be included.
  13. There shall be an internal switch to select manual or automatic bypass.
  14. Normal/Test selection via touch pad shall allow testing and adjustment of the VFD, while the motor is running in the bypass mode.
  15. Hand/Off/Auto selector shall provide the following operation
  1. Hand Position –Once the start command is given, the drive shall run with local speed command and reference. If in bypass mode, the motor shall run with across the line power.
  2. Off Position –All the start commands shall be removed, all speed inputs ignored, and the motor shall be stopped.
  3. Auto Position - The drive shall be enabled to receive a start command and speed input from a building automation system. If in bypass mode, the motor start/stop shall be controlled by the building automation system
  1. Annunciation contacts for Auto Mode, drive fault, bypass run and motor OL.
  2. Damper control circuit with end of travel feedback capability.
  3. H/O/A control panel selection via touch pad or rotary switch types.
  1. Integral Soft Start on transfer to bypass shall be offered as an option if required by the schedule.
  1. Enclosure:

The enclosure shall be of one of the following types depending on the schedule:

  1. NEMA 1 extended enclosure, to house additional equipment within the VFD enclosure for VFDs not requiring Bypass.
  2. NEMA 12 Positive Pressure, Blown & Filtered (PPBF) enclosures with filters and blower.
  3. NEMA 3R enclosures for outdoor installations.
  1. RFI (Radio Frequency Interference) filters to further attenuate possible VFD generated noise shall be provided in critical applications. The RFI filters may be provided in a separate enclosure.
  1. Current limiting input fusing with disconnect shall be provided for short circuit protection of VFD semiconductor devices.
  1. Pressure transducer (3 to 15 PSI input to a 0 to 10 V DC output), will be provided if necessary.
  1. Output reactors and/or filters can be provided for motors not meeting latest NEMA MG-1 standards
  1. PC software for parameter upload/download/graphing shall be included

2.06 FABRICATION