Reliance VTAC 7 Specifications 1-400 HP @ 460 Volts 1-100 HP @ 208 Volts

VARIABLE FREQUENCY DRIVES

This specification should be used to define the requirements for a 1 through 400 HP at 460 Volts and 1 through 100 HP at 208 Volt Variable Speed Drive.

1.0 GENERAL

A single manufacturer of both motors and drives shall provide, coordinate, and start-up a variable speed drive system to ensure proper application of equipment to the driven load. The Variable Frequency Drive and Motor shall be manufactured by Reliance Company.

A. Motor and VFD shall be of the same manufacturer for single source responsibility. Factory warranty for a period of at least 3 years from date of start up shall apply for both motor and drive

B. VFD shall be current rated at 8 kHz carrier frequency for VFD's 1-75 HP and 4 kHz for VFD's 100-400 HP. All HP ratings shall meet or exceed Table 430-150 of the National Electric Code. Three Phase Motor Full Load Currents, HP, Maximum Current, and Rated Voltage shall appear on the drive nameplate.

C. VFD shall not generate damaging voltage pulses at the motor terminals when applied within 500 feet of each other. Both Drive and Motor shall comply with NEMA MG1 section 30.40.4.2 which specifies these limits at a maximum peak voltage of 1600 Volts and a minimum rise time of .1 microseconds.

1.1 CODES/STANDARDS

A. VFD and options shall be c UL* 508 listed.

B. NEMA 12 enclosed VFD shall be UL ä 1995 approved for mounting in conditioned air ducts and plenums.

C. The drive and options shall comply with the applicable requirement of the latest standards of ANSI, NEMA, National Electric Code NEC, NEPU-70, IEEE 519-1992, FCC Part 15 Subpart J, CE 96.

1.2 QUALITY ASSURANCE

Each drive shall be subjected to the following test and quality control procedures.

A. Every VFD shall be functionally tested under motor load. During this load test the VFD shall be monitored for correct phase current, Phase voltages, and motor speed. Correct Current Limit operation shall be verified by simulating a motor overload.

B. Verification of proper factory presets by scrolling through all parameters shall be performed to ensure proper microprocessor settings. The computer port should also verify that the proper factory settings are loaded correctly in the drive.

C. All options shall be functionally tested including operation of a motor in the ByPass mode if supplied. Proper heater coil installation in motor overload, if supplied, shall be verified.

1.3 SERVICE

The VFD manufacturer shall maintain and staff world-wide service centers. The manufacturers shall have the ability to test both the drives and motors in these service centers.

A. Start-up shall be included for each VFD provided.

B. Service engineers shall be employed by the manufacturer or be certified by the manufacturer and provide start-up service including physical inspection of drive and connected wiring and final adjustments to meet specified performance requirements.

2.0 DRIVE FUNCTIONS

The VFD shall have the following basic features:

A. An electronic overload circuit designed to protect an AC motor operated by the VFD output from extended overload operation on an inverse time basis. This Electronic overload shall be ULä and NEC recognized as adequate motor protection. No additional hardware such as motor overload relays or motor thermostats shall be required.

B. An LED display mounted on the door of the cabinet that digitally indicates:

1. Frequency output
2. Voltage output
3. Current output
4. Motor RPM
5. Input kW
6. Elapsed Time
7. Time Stamped Fault Indication
8. DC Bus Volts

C. The VFD shall have the capability of riding though power dips up to 10 seconds without a controller trip depending on load and operating condition. In this extended ride through, the drive shall use the energy generated by the rotating fan as a power source for all electronic circuits.

D. RS232 Port and Windowsä based software for Configuration, Control, and Monitoring.

E. An isolated 0-20mA, 4-20mA or 0-4, 0-8, 0-10 volt analog speed input follower.

F. An isolated 0-10 V or 4-20 mA output signal proportional to speed or load.

2.1 PROTECTIVE CIRCUITS AND FEATURES

The VFD shall include the following protective circuits and features:

1. Motor current exceeds 200% of drive continuous current rating.
2. Output phase-to-phase short circuit condition.
3. Total ground fault under any operating condition.
4. High input line voltage.
5. Low input line voltage.
6. Loss of input or output phase.
7. External fault. (This protective circuit shall permit wiring of remote N.C. safety contact to shut down the drive). User supplied end switches, thermal switches, fire-stats, freeze-stats inputs will be connected to this VFD supplied circuit.
8. Metal oxide varistors for surge suppression shall be provided at the VFD input terminals.

2.2 GENERAL OPTIONS AND MODIFICATIONS

The following options shall be included as specified in the document:

A. Complete Contactor ByPass shall be provided to allow motor to be safely transferred from VFD output to the AC line, or from the AC line to the VFD, while the motor is at zero speed. The contactor ByPass shall utilize two motor contactors electrically interlocked. One contactor is to open and close the connection between the VFD output and the motor. The other contactor will open and close the connection between the ByPass power line and the motor, providing "across the line" starting. Motor protection is to be provided in the "ByPass" mode by a bi-metallic Class 20 Smart Motor Protection adjustable overload relay. Relay control logic shall also be included within the VFD enclosure to allow the same "START/STOP" command to operate the motor in either mode. The relay logic shall be 115 Volts. The ByPass circuit shall include a second disconnect installed in the VFD to provide the ability to safely troubleshoot and test the controller , both energized and de-energized, while the motor is running in the "ByPass" mode. A contact closure shall be provided to indicate that the drive is in the "ByPass" mode. A Remote/Local selector switch shall also be provided to transfer control from the keypad to user wired signals. Form "C" Normally Open and Normally Closed contacts shall be provided for both Run and IET/Drive Stopped. The entire ByPass option shall be packaged with the controller enclosure and be mechanically isolated from the VFD.

B. Input line fuses shall provide protection for the input rectification circuit using Class J fuses with interrupting rating of 200,000 AIC. The series interrupting rating of the VFD and fuses shall be a minimum of 30,000 AIC and shall be stated in the VFD Instruction Manual as required by UL

C. A main input disconnect shall mount within the standard NEMA 1 or NEMA 12 enclosure for positive power disconnect of the VFD. It shall have the capability for door padlocking.

D. A three phase 3% impedance Input Line Reactor shall be provided to minimize drive harmonics on the AC line and protect the drive from damaging electrical system transients.

E. Johnson Controls Metasys(tm) option card allows direct connection from the VTAC 7 to the Johnson N2 bus architecture. All configuration and control functions can be accessed through this card. Allows direct communication between the VTAC 7 microprocessor and the host Johnson system. Fault diagnostics, start/stop, speed commands, and all drive feedback's shall be available over a single RS485 communication connection. Discrete signals such as ByPass Run or Interlock Open shall also be mapped through the drive terminal strip to the Metasys system. The card shall have the ability to be used in a "monitor only" mode where control shall be from a AHU or similar type controller directly wired to the drive.

Reliance document d510
January 1998