E3 Adjustable Speed Drive
Engineering Specification
PART 1 - GENERAL
1.0 Scope
This specification shall cover Toshiba E3 AC Variable Frequency Drives, 6 pulse for 230V and 460V.
1.1References
A.National Electric Manufactures Association (NEMA)
B.Underwriters Laboratories, Inc. (UL) and CSA
C.National Electric Code (NEC)
D.IEEE 519. Compliance of IEEE 519 can be determined after Toshiba performs a harmonics analysis. The analysis will be done after we receive a completed harmonics questionnaire.
E.ISO 9001
1.2Submittal
Submittals shall include Toshiba standard operation manual. Schematics can be obtained from factory upon request.
PART 2 – E3 VARIABLE FREQUENCY DRIVE
2.0General
A.This specification covers AC adjustable frequency drives for HVAC applications.
B.The manufacturer shall not have less than fifteen years of experience in the manufacture of VFD’s.
C.The manufacturer shall manufacture both AC drives and motors at the same facility.
D.The drive shall be manufactured in the United States.
2.1Design Criteria
A.The drive should be a PWM (Pulse Width Modulated) transistorized inverter using IGBT’s (Insulated Gate Bipolar Transistors) and must be fully digital.
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B.The drive shall utilize Insulated Gate Bipolar Transistor (IGBT’s) in its power section.
C.The E3 VFD shall have 3 basic design criteria
1)Rectifier Section that shall include diode bridge rectifier to convert AC to DC.
2)Filtering Section that shall include capacitors to eliminate “ripple” affect on the DC bus to produce smooth DC bus voltage.
3)Switching Section that shall included Insulated Gate Bipolar Transistors (IGBT) to provided Pulse Width Modulation.
2.2Ratings and overload capability of the VFD
A.The drive main input power shall be:
I. 200V/50Hz or 200V-230V/60Hz for 230V models
II.380V-415V/50Hz or 400V-460V/60Hz for 460V models
B.The drive shall have a tolerance for voltage ± 10% and frequency ± 2Hz.
C.The drive overload current shall be 100% continuous and 110% for 1 minute.
D.The drive should have a common design for all horsepower models:
230V – 3 through 60HP
460V – 5 through 125HP
2.3Control Features
A.The drive shall have True Torque Control with Automatic energy-saving control.
B.The drive shall have two (2) frequency priority selection feature.
C.The drive shall be capable of setting both upper and lower limit frequencies.
D.The ASD shall automatically adjust the PWM carrier frequency proportional to speed. The range of automatic adjustment shall vary from 15khz to .5khz. The minimum acceptable full speed carrier frequency (60 Hz) with no derating shall be 8 kHz.
E.The drive shall be capable of PID set point control.
F.Preset macros for typical HVAC applications such as pumps, fans, cooling towers.
G.Serial RS232C communications standard.
H.Automatic cooling fan control based on heat sink temperature for extended fan life.
I.The drive shall be able to start and stop from a two-wire control (dry contacts), three wire momentary contact closure, keypad, and serial interface.
J.The drive shall be able to act as a space heater for a motor when the system is not running.
K.The drive shall have adjustable input and output terminal response time selections to prevent noise effects and chattering.
L.The drive shall have a built-in control system for commercial power/inverter power switching.
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M.The drive shall have an adjustable retry function after a fault. Both number of attempts (at least 10) and time between (1-10 sec).
N.The drive shall have an adjustable output short circuit detection selection for standard motor and high-speed motors (very low inductance).
O.The drive shall have two programmable: volt per hertz patterns, maximum output frequencies, electronic thermal protection settings, stall protections, base frequencies, voltage boosts, and stall protection selections which can be chosen while running to run motor A or motor B.
P.The drive shall have an analog input filter adjustment to limit the effects of noise on the control signal.
Q.The drive shall permit switching between local/remote operation as well as manual/auto “on the fly.”
R.The drive shall have the ability to ignore run commands until a “dampers open” signal is received. In the event a “dampers open” signal is absent the drive shall be capable providing a “close damper” signal. Upon receipt of “drive stop” signal The ASD shall be capable of providing a close damper signal.
S.The drive shall be provided with “anti-windmilling” or “motor shaft stationary control”
T.The drive shall have the following user selectable contingencies in the event of loss of analog control signal while the drive is running before loss:
i.Run at the user set lower frequency limit.
ii.Run at the user set upper frequency limit.
iii.Trip with a signal loss fault.
iv.Run at user-selected percentage of the last valid frequency signal.
2.4Operational Functions
A.The drive shall contain two separate acceleration/deceleration times with auto tuning for optimum setting (0.1 to 6000 seconds) with choice of linear, S, or C curves.
B.The drive shall be equipped with both local/remote and manual/auto keys on touch pad.
C.The drive shall be equipped with a quick setup key with 18 most frequently parameters in a HVAC type application.
D.The drive shall contain fifteen preset speeds, which can be activated from the keypad, terminal inputs, and host computer.
E.The drive shall have the capability of storable special custom user setting.
F.The drive shall restart into a rotating motor operating in either the forward or reverse direction and match that frequency.
G.The drive shall have adjustable soft stall (10% - 150%) which reduces frequency and voltage of the inverter to sustain a run in an overload situation.
H.The drive shall be capable of performing a time base pattern run using 4 groups of 8 patterns each using the 15 preset speed values for a maximum of 32 different patterns.
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