SECTION 26 18 39
MEDIUM VOLTAGE SOLID STATE REDUCED VOLTAGE CONTROLLERS
PART 1 - GENERAL
A. This Section includes NEMA Class E2 medium voltage metal-enclosed motor controllers with
fused power assemblies and medium voltage motor controllers with drawout-type construction.
This specification describes the performance, functional specifications and fabrication details for
a reduced voltage, stepless, solid state medium voltage motor starter that shall provide a
selectable voltage ramp, current limit or current ramp (all standard) method of soft starting 3-
phase AC induction motors.
B. Each motor controller shall be a complete self-contained Class E-2 Combination Starter,
including disconnect means, main contactor, solid-state controller, motor overload protection
and bypass contactor.
1.2 RELATED DOCUMENTS
A. Drawings and general provisions of the Contract, including General and Supplementary
Conditions and Division 1 Specification Sections, apply to this Section.
A. Submit shop drawings and product data for approval and final documentation in the quantities
listed according to the Conditions of the Contract. All transmittals shall be identified by
purchaser name, purchaser location and purchaser order number.
B. Documents for Approval: Dimensioned plans, sections and elevations showing minimum
clearances, installed devices, major features, nameplate legends and bills of material.
C. Final Documents: Record documentation to include those documents listed in 1.4.B and wiring
diagrams and three-line diagrams, product data of accessories or parts not previously described
in the drawings, list of recommended spare parts, and instruction and installation manuals
D. Product Data: Include features, characteristics and ratings of individual contactors, fuse
assemblies and other components. Also include time-current characteristic curves or data for
power fuses and overcurrent protective devices.
E. Shop Drawings: General arrangement drawing showing dimensioned plan, elevation, and
details, including required clearances and service space around equipment. Show tabulations
of installed devices, equipment features and ratings. Include the following:
1. General arrangement drawing, including enclosure type
2. Nameplate legends.
3. Bus configuration with size and number of conductors in each bus run, including phase
and ground conductors of main and feeder buses.
4. Current rating of buses.
5. Short-circuit current rating of controller assembly.
6. Wiring Diagrams: Diagram power, signal and control wiring including differentiation
between manufacturer-installed and field-installed wiring.
7. All drawings shall be in AutoCAD format and shall be available in electronic form.
1.4 RELATED STANDARDS
A. Comply with requirements of latest revisions of applicable industry standards, specifically
including the following:
1. UL 347 - Medium Voltage Controllers
2. NEMA ICS 3-2000, Part 1 – Medium Voltage Controllers
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B. Units up to 360A at 5kV or 7.2kV shall be UL / cUL listed at the factory as a complete assembly
where arrangement and device selection allows.
1.5 QUALITY ASSURANCE
A. Manufacturer Qualifications: Engage a firm with at least 15 years experience in manufacturing
Class E2 controllers.
1.6 DELIVERY, STORAGE AND HANDLING
A. Deliver products in factory labeled packages. Shipping groups shall not exceed 12 ft. in length.
B. Store and handle in strict compliance with manufacturer’s instructions and recommendations.
Protect from potential damage from weather and construction operations. Store so
condensation will not form on or in controller, and if necessary, apply temporary heat where
required to obtain suitable service conditions.
PART 2 - PRODUCTS
A. [The medium voltage controller assembly shall be manufactured by Siemens or pre-approved
equal. Approved manufacturers are as follows:
2. . ]
A. [System Configuration: Controller assembly suitable for application in three-phase, three-wire
[60Hz] [50Hz], [grounded] [ungrounded] system.]
B. [Electrical Ratings
1. Nominal System Voltage, kV: [2.3] [4.16] [6.6] [13.2.]
2. Maximum Design Voltage, kV: [2.4] [4.8] [7.2] [15.0]
3. Frequency: [60Hz] [50Hz]
4. Horizontal bus continuous amperes:   
5. Vertical bus continuous amperes: [as required for equipment arrangement]
6. Ground bus size: ¼ by 2 inches
2.3 GENERAL REQUIREMENTS
A. The controller shall be factory assembled and tested and comply with applicable industry
standards. It shall be a coordinated design so that shipping groups are easily connected
together at the site into a continuous lineup. Necessary connecting materials shall be furnished.
Bus splice plates and hardware shall ship installed in the equipment to prevent loss during
shipment. All contactors and assemblies shall be produced in an ISO-9000 certified facility.
B. The controller assembly shall consist of one or more metal-enclosed sections in an [indoor
NEMA 1] [indoor NEMA 1 gasketed] [indoor NEMA 2] [indoor NEMA 12] [outdoor NEMA
C. Individual vertical sections shall be to accommodate drawout controller assemblies without de-
rating and shall include:
1. Fabricated of minimum 11 gauge steel for the frame, minimum 12-gauge for doors.
Typical dimensions shall be 36” wide, 36” deep, and [90” (without main bus)] [100” (up
to 7.2kV and 2000A main bus)] [106” (up to 3000A main bus)] high.
2. [End sections shall include provisions for main bus extension and installation of
future vertical sections.] (Applicable only if main bus is specified.)
3. The design shall incorporate preformed steel channels, angles and side sheets bolted
together and reinforced to form a rigid, self-supporting assembly.
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D. Fabricate with dead-front construction utilizing sheet steel barriers for isolation of the power bus
compartments from the drawout controller area. Include sliding shutter mechanism to
automatically cover the line side stab connections whenever the controller drawout carriage is
racked off the bus. The rear of each section to be provided with a two-piece removable steel
sheet barrier for access.
E. Power (horizontal) bus shall connect vertical sections and between compartments and shall not
1. Bus shall be [98% minimum conductivity copper with silver-plated joints] [98%
conductivity copper with tin-plated joints]
2. Ground Bus shall be copper of 98% minimum conductivity, minimum size 1/4 by 2 inches.
3. Busbars shall be bare, except where clearance considerations require that the bus be
insulated. [OPTIONAL: Busbar insulation shall be heat shrink sleeving. Bolted bus
joints requiring insulation shall be insulated with secure joint covers or taped.]
F. Finish: Steel parts shall be prepared for painting by a five-stage wash system consisting of an
alkaline cleaner, fresh water rinse, iron phosphate treatment, fresh water rinse and non-
chromate sealer. After cleaning and stabilization, the steel parts shall be coated with a
thermosetting polyester urethane powder applied with electrostatic equipment at a nominal 2
mils dry film thickness and then cured properly. The paint finish shall have a pencil hardness of
2H, a salt spray rating as defined in ASTM B-117 of 600 hours. Paint color shall be ANSI light
G. Solid state reduced voltage motor starters shall be Siemens Series 81000 sized as indicated, or
pre-approved equal modified to meet the requirements of this specification. The starter shall be
complete with the following standard features and adjustments. Starters not including all of the
listed features shall be provided with a digital Motor Protection Relay and any necessary options
which provide these functions, and any redundant features shall be turned “off” in the solid state
starter to avoid confusion.
1. Motor and Load Protection based upon modeling of the thermal characteristics of the
motor. User entries shall include motor nameplate FLA, Service Factor, NEMA Design,
Insulation Class, Line Voltage and Line Frequency. All current referenced protection
features shall be calculated from the FLA and automatically adjusted for time based on a
Real Time Clock, remaining active through any power loss.
2. Thermal Overload provided by the on-board microprocessor. As the most important
protection feature of a starter, the overload protection shall be based on a Dynamic
Thermal Register retained in memory. The register shall be created using programmed
data such as: FLA, LRA, Cold Stall Time, Hot Stall Time, Stopped Cool Down Time and
Running Cool Down Time. Measured data such as Phase Current Imbalance and RTD's
[Optional] must bias the thermal register to provide quicker tripping if needed. Overload
shall also feature:
a. Separate Trip Curves for Start and Run, allowing a higher level curve to avoid
nuisance tripping during acceleration, but dropping to another level for accurate
motor protection while at full speed. To maximize flexibility, each trip curve shall be
programmable as follows:
1.) Basic protection shall be inverse time-current trip curves using NEMA Class
5 -30 trip curves. The starter shall be UL listed to provide each individual
2.) Locked Rotor programmable between 400 – 800% of FLA, and a trip time
from 1 – 30 seconds.
3.) Measured Start Capacity (I*I*T curve area) taken from the previous
successful start (only applicable to the Start Curve).
b. Retentive Thermal Memory shall be used to ensure that the Dynamic Thermal
Register shall be automatically updated as to the motor temperature while the
power was off.
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c. Dynamic Reset Capacity to allow enough cooling time for a successful restart after
an overload trip, based on a running average of data learned in 6 previous
d. Overload Alarm providing a warning to users of an impending overload trip..
e. Manual or Automatic Reset.
3. Phase Current Monitoring. To protect against disconnected motor leads this feature will
function even if the line voltage remains normal. All features shall be as follows and
capable of being defeated if desired:
a. Phase Current Loss with an adjustable trip delay
b. Phase Imbalance Protection with programmable Alarm and Trip points and
adjustable delay times. This feature shall also be used to bias the Dynamic
Thermal Resister for protecting the motor from rapid temperature increases
caused by current imbalance.
4. Short Circuit Detection with dual mode protection for starting and running operation shall
be standard. This circuit MUST be provided to protect the starter from load failures. This
protection shall be implemented by hardware and non-adjustable.
a. In the starting mode, the starter shall employ a ¼ second pre-check routine to
determine if the load circuit has a fault condition and disable the ramping prior to
reaching the Initial Voltage setting. This is to avoid additional equipment damage
after a fault that may have occurred while the starter was off.
b. In the running mode, this feature will shut down the starter if current through any
leg exceeds 10 times unit FLA for 12.5 milliseconds.
5. Over Current Protection (Shear Pin trip), adjustable from 100% to 300% FLA with time
6. Under Current Protection (Load Loss) programmable from 10% to 90% FLA, with time
7. Line Voltage protection, including Over and Under voltage with adjustable trip delays.
8. Ground Fault using the Zero Sequence method, shall be available as an option with 3
levels adjustable from 5 – 90% of the CT value as follows:
a. ALARM level preset at 5% with a 0.5 – 20 second delay.
b. LOSET Trip level preset at 7% with a 1 – 20 second delay.
c. HISET Trip level preset at 10% with an 8 – 250 millisecond delay.
d. For high resistance grounded systems, a Core Balanced CT can be added to
provide true Zero Sequence Ground Fault protection at the same programmable
9. Line Frequency Window with a programmable variance of 1 – 6Hz from nominal line
frequency with trip delay.
10. Coast Down Lockout to prevent restarting of the motor during backspin or other
dangerous mechanical conditions after shutting off. The coast down lockout time shall be
programmable between 0 and 60 minutes following a Stop command.
11. Starts-per-Hour Lockout to prevent damage to the motor from rapid cycling of start
commands for any reason. The maximum starts-per-hour shall be programmable
between 1 and 10 starts
a. Time Between Starts Lockout to work with the above. A minimum time of 0 and 60
minute between start attempts shall prevent restarting too rapidly for the motor and
12. Acceleration Control shall be fully adjustable to match any application. As a minimum,
starter shall come complete with the following settings:
a. Ramp Types: To ensure maximum flexibility in matching the load conditions in the
field, the starter shall provide all of the following methods of acceleration ramp
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control: Voltage Ramp, Voltage Ramp with Current Limit, Current Limit Only
(Current Step), Closed Loop Current Ramp (Torque Ramp) or up to 3 Custom
Ramp profiles that can be programmed by the user.
b. Starting Torque: programmable as either Current or Voltage output, adjustable
between 0-100% of maximum Locked Rotor Torque (600% current).
c. Maximum Current Limit: adjustable between 200 and 500% of the motor FLA.
Lighter duty starters with lower current limit settings will not be acceptable.
d. Ramp Time: adjustable between 1 and 120 seconds.
e. Dual Ramps: the starter shall provide 2 separately adjustable ramp profiles,
selectable via a dry contact closure. Each ramp will provide the above features and
be available with all other options.
f. 3 Custom Ramp Curves shall be available that can be configured by the user to
match any load or starting condition, profiled by entering 8 torque and time points.
g. Kick Start: for starting of difficult loads, will apply a high output for a short time on
initial start command, adjustable from 10 – 100% voltage, for 0.1-2 seconds max.
h. Jog: for start-up rotation check or other testing procedures. Adjustable from 5 –
75% of line voltage.
i. Pump Deceleration Control (Ramp Down) shall be completely independent of any
Accel Ramp settings and provide a fully adjustable Decel profile in order to avoid
possible motor damage. Pre-programmed decel “algorithm” systems that do not
allow contouring to match load conditions are not acceptable.
j. Step Down Voltage: adjustable from 100 to 0% of line voltage, allowing the motor
torque to drop off immediately to a level that affects output without waiting for a
k. Deceleration Ramp Time: adjustable from 0 – 60 seconds to allow gentle
controlled deceleration in excess of the natural coast-to-stop time of the load.
l. Stop Voltage Level, adjustable from 100 – 0% of line voltage to automatically turn
off the starter when the output torque has reached a desired level.
13. Selectable Operation During Overload, shall be available to allow the user to decide if the
motor shall turn off immediately or continue with Decel when an overload condition is
14. Starter Protection shall be provided to maintain reliability of both the equipment and the
circuit components, with the following features:
a. Shorted SCR / Wrong Connection Detection to prevent a “start” when one SCR is
shorted or an error has been made in initial connection of the unit.
b. Starter Over-Temperature Trip to protect the SCRs from excessive heat build-up in
15. Inputs shall be provided for the control and option selection of the starter as follows.
a. Digital Inputs All input and control devices shall be rated for 120VAC control or
shall require dry contact closures without the need for external power supplies or
1.) On-Off Control can be for 2 wire or 3 wire control schemes. Seal-In relay
contact for the 3 wire control scheme shall be internal, dedicated to that use
and not counted as an output contact.
2.) User Input: 4 digital inputs shall be provided that are programmable as N.O.
or N.C. and can be named for display on the Operator Interface. Each input
shall include a programmable de-bounce timer and be assignable to operate
any of the user available digital outputs or trip functions.
16. Analog Input (1) using 4-20mA with adjustable offset and gain for use with the
Tachometer Feedback Ramp control option.
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17. Outputs shall be provided for the following functions in addition to the seal-in relay used
in 3 wire control schemes as mentioned above.
a. 8 Digital Outputs, form “C” relay outputs, programmable as “Fail-Safe” or not, and
rated for 240VAC, 5A, 1200VA max. Each relay shall be independently
programmable to operate on any of the following functions;
1.) Indicator Relay, programmable to change state on any of the following
Start / Stop, Start / End of Decel, Timed Output, At Speed / Stop, At Speed /
End of Decel, Dual Ramp Selected, Self Test Fail,
2.) Fault Trip Relay, programmable for each of the following fault conditions:
Overload, Phase Imbalance / Loss / Reversal, Lock Out Inhibits, External
Inputs, Short Circuit, Over / Under Current, Over / Under Voltage, Power
Factor High / Low, Shear Pin, Ground Fault HISET / LOSET, Over / Under
Frequency, I2T Start Curve, Shorted SCR, Shunt Trip, Over Temp.
3.) Alarm Relay, including the following conditions:
Overload Warning, Overcurrent Warning, Ground Fault Warning, Under
Current Warning, Imbalance Warning, Thermal Register Warning.
4.) RTD Relay (when option supplied) includes Stator or Non-Stator Trip and/or
Warning, and RTD Failure.
b. Analog Outputs (2) shall be provided for sending information to external controls,
programmable as RMS Current or Percentage of Motor FLA.
1.) If the Tach Feedback Starting option is used, the Analog outputs can be
programmed as RPM.
2.) If the RTD input option is used, the Analog outputs can be programmed as
Hottest RTD Temperature for Stator or Non-Stator RTDs.
18. Operator Interface Panel with backlit 2 line by 20 character LCD providing simple to use
adjustment and status indication on a dead-front panel of the low voltage compartment,
with the following:
a. Keypad with tactile feedback keys for high noise environments. To prevent
confusion, no binary coded dipswitches shall be used for programming.
b. 12 LED Indicators providing additional quick annunciation of Power, Run, Alarm
and Trip operation, as well as the status of the eight output relays.
c. Password Protection allowing 3 levels of access to program information, 2
requiring separate Passwords.
19. Metering functions through the Alpha-Numeric Display for indicating the following;
a. Output Current, Line Voltage, Power Factor, kW, kW Demand, kVA, kVA Demand,
kVAR, kVAR Demand, Motor Load % of FLA, Line Frequency, Phase Order and
Ground Fault (when included)
b. Remaining Thermal Capacity to indicate heating effect and cooling rate of the
motor. Range shall be 0 – 100% of the remaining capacity and count up towards
100% while cooling.
c. Thermal Capacity to Restart, averaged from the previous 6 successful starts,
indicating the required value of the Dynamic Thermal Register to successfully
restart after an Overload Trip.
d. I*I*T to Start, measured from the previous start.
e. Starter Status, including Ready, Starting, Running, Last Trip Cause.
20. Statistical Data recorded and viewable through the operator interface, including the
following: Elapsed Run Time, MWh, Current Unbalanced, Stator and Bearing RTD Trips,
Over Voltage and Under Voltage Trips, Power Factor, Phase Reversal, Total Trips, Trips
on Short Circuit, Start O/L, Run O/L, Frequency, Overcurrent, G/F LOSET and HISET,
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Acceleration Time, Start Under Curve, Start Over Curve, I*I*T Start, Fail Shunt Trip,
Phase Loss, Tach Accel, and Digital Input Status
21. Starting Data, learned from previous successful starts, including Average Start Time.
Average Start Current and Last Start Time.
22. Time Values, including remaining time for O/L Trip, Thermal Inhibit, Coast Down Lock
Out, Time Between Starts and Starts per Hour.
23. Trip Record, including separate data sets for:
a. Last Trip, including Cause, Phase and GF currents, Unbalance %, Hz, Hottest
Stator and Non Stator RTD (with option) recorded.
b. Event Recorder, last 60 events with Time, Date, Phase and GF currents record at
24. Learned Start Curve. 100 data points of current and time between Start and At-Speed.
This data can be exported via the Comm. Port to be plotted on a graph or spread sheet
for baseline measurement and maintenance analysis.
25. (Optional) [RTD Inputs. Allowing biasing and adjustment of the Dynamic Thermal
Register based on real-world temperature readings from up to 12 RTDs. Separate
RTD modules that do not provide Thermal Register Biasing will not be acceptable.
RTD option card will provide the following features:
a. Programmable RTD Type, shall accept 100 ohm platinum, 100 ohm nickel,
120 ohm nickel and / or 10 ohm copper RTDs
b. Configurable RTDs, allowing for up to 6 RTDs to be used for the Stator. All
RTDs can have names assigned in programming for clear indication on the
c. RTD Voting, providing for the requirement of at least 2 RTDs to be exceeding
the setpoints for Trip or Alarm. This feature shall be programmable as
Enabled or Disabled.
d. RTD Metering for Stator and Non Stator RTDs, displayed in degrees C and
degrees F. Metering includes Hottest RTD, each RTD Temp, each RTD Max
Temp Since Clear, Measured Run Cool Time in minutes, and Measured Stop
Cool Time in minutes.]
26. (Optional) [Tachometer Feedback Starting for accomplishing linear speed
acceleration by using an analog input to an internal PID ramp control function from
a user supplied 4-20ma tachometer. Tach Feedback Protection with over speed
and under speed trips (when a 4-20ma signal is provided).]
27. Serial Communications shall be built-in as a standard feature without the need for
separate modules. Communications protocol shall be RS-232 to a windows based
program for data entry, or Profibus, or Modbus RTU protocol via RS485 signals. Units
shall be capable of being connected to an intelligent communication device in a network
of up to 247 devices with unique addresses
28. Safety Isolation of all sensors and control circuits shall be via magnetic or fiber optic
means. Gate pulse signals, current feedback, Ground Fault CT feedback and heat sink
temperature shall all be isolated via fiber optics. Control power and line voltage sensing
shall be magnetically isolated using proper medium voltage class Potential Transformers
with fusing. Voltage divider resistor cards shall not be permitted.
2.4 DESIGN SPECIFICATIONS
A. Power Ratings [2.3kV] [4.16kV] [6.6kV] [13.2kV]
1. Input: +10% to –15% 3 phase 50 / 60Hz (selectable) ± 6Hz, as indicated on the drawings.
2. Output: Reduced voltage 3 phase AC derived from phase-angle fired inverse-parallel
thyristors, ramped to full voltage.
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3. Current Rating(s): [360A (to 7.2kV] [720A (to 5kV)] [300A (to 15kV)] (choose size for
4. Output Capacity: Heavy Duty, rated as follows. Overload Capacity; 500% of unit rating for
60 seconds, 600% for 30 seconds; minimum 115% of nominal motor FLA continuous
based on rating of the Bypass Contactor. SCR power devices shall be rated for a
minimum of 125% of the motor FLA.
5. Control Power: 120VAC, 60Hz, derived from an integral transformer sized to be
adequate to operate all associated devices in each starter.
B. Power Structure
1. Disconnect Means: A disconnect means (drawout main contactor or drawout fuse
carriage) shall be provided in the incoming power section of the starter assembly. The
disconnect means shall be padlockable in the “Open” position. Lockout coordination with
adjacent compartments will be as follows;
a. The incoming line section door cannot be opened if the disconnect means is in the
closed position. The disconnect means cannot be closed if the incoming line
section door is open.
b. All other associated doors in sections containing medium voltage potential shall be
interlocked with the incoming line section door by either direct mechanical means
or by use of key interlock mechanisms.
2. Power Fuses: As a NEMA class E2 controller, current limiting primary power fuses shall
be provided for each incoming phase.
a. Fuses shall be ANSI class R for motor starting duty, except where class X or class
E are required for the duty, sized according to motor locked rotor current and
coordinated with the overload relay. Fuse and overload coordination shall be
designed to allow the controller and contactor to clear low and medium level faults
without opening and without exceeding the contactor interrupting ratings.
b. Fuse holders shall include blown fuse indicators, wired to the isolation contactor
circuit to disconnect all three phases if any one of the fuses clears.
3. Line and Bypass Contactors: Vacuum contactors shall be provided for both Line and
a. For 360A (up to 7.2kV), main contactor shall be drawout type, with primary current
limiting fuses mounted on the same drawout carriage. For 720A (up to 5kV) or
300A (up to 15kV), the main contactor shall be fixed-mounted, and the primary
current limiting fuses shall be mounted on a drawout carriage, with interlocking as
required between the contactor and the drawout carriage. Each controller shall
consist of a magnetically held contactor    ampere, primary fuses
for short circuit protection and to include the following:
b. Bypass contactor shall be fixed mounted.
c. A sequencing feature shall control the contactors to maximize life. Under normal
operating conditions, it will ensure that contactors make and break under no-load
d. Vacuum contactors shall be rated for maximum starting current of the unit design,
and capable of across-the-line start for emergencies. A separate thermal overload
relay shall be provided for use should the normal electronics become unavailable.
4. Bus Bars: All power bus is to be isolated behind barriers. Automatic shutters are to be
provided to cover the line-side bus stabs whenever a starter door is opened. (Optional)
a. Vertical tap buses in each section are sized for the application.
b. (Optional) Insulated bus with boots are to be provided.
5. Rated Short Circuit Current
6. Overall BIL Rating: Entire starter assembly shall have a BIL (Basic Impulse Level) rating
of [60kV (for up to 7.2kV)] [95kV (for up to 15kV)].
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C. SCR Modules
1. PIV Ratings: SCRs will be connected as inverse parallel pairs in series circuits to attain
the following Peak Inverse Voltage ratings as a minimum for each phase:
System Voltage: 2300V Pairs: 1 PIV Rating. 6500V
System Voltage: 4160V Series Pairs: 2 PIV Rating. 13000V
2. Protection: RC snubber network circuits on each SCR pair. To avoid possible component
damage, MOV protective devices shall be used only on the gate firing circuitry.
3. Efficiency: 99.7% through SCRs.
4. Control Method: To ensure reliable gate firing even when powered with on-site
generators, firing circuits shall use a 6 pulse locked phase transformer coupling method
for maximum isolation and rapid rise of firing pulses.
a. Sensing of the line voltage phase angles for firing control shall be done using
magnetically isolated Potential Transformers. Systems using voltage divider
resistor networks shall not be permitted.
5. Noise Immunity: The gate firing circuitry shall be protected from electrical noise and
transients to ensure reliable starting and firing of the SCRs under all power conditions,
regardless of the available fault current or motor lead length.
a. They shall be amplified and isolated from the control voltages by means of rugged
encapsulated ring transformers that provide separate power sources for each set
of SCR gate drives. The design shall also allow for a DC carry-over of the firing
pulse to prevent the SCRs from falsely turning off due to ringing of the output
current or line notching caused by other connected equipment. The gate drive shall
be maintained for 240 electrical degrees from the zero cross point to avoid
premature turn-off of the SCRs caused by motor or motor lead transients.
b. For additional reliability and to protect against EMI/RFI interface generated by
internal components, connections to and from the Digital Control Unit shall be fiber
optic type for gate firing, current feedback, temperature feedback and the
(Optional) Ground fault CT signals.
c. When at all possible the starter shall not require line reactors in the Medium
Voltage power section. Those that do shall include them within the same enclosure
as the starter, and the entire assembly shall be UL listed with the reactors
installed. Any heat calculations for the enclosure and equipment room shall take
the losses through the reactor into account as additional heat gain. To avoid
possible coordination problems and wiring errors, field installation of the reactors
will not be allowed.
D. Ambient Conditions
1. Temperature: 0 – 40° C (-32 to 102° F)
2. Altitude: 3300 ft (1000 m) maximum without derating.
3. Humidity: 0 – 95% RH, non-condensing.
4. Thermal: Heat sink temperature switches designed to trip at 85° C.
1. Non-Volatile Memory will be used throughout the control and protection systems. User
programming and data shall be stored in EEPROM memory. Loss of power shall not
affect memory status. For fast updates and operation, running data shall use battery
backed SRAM memory. The starter shall store critical values of the SRAM memory
contents to the EEPROM upon power failure, and restore it upon return to normal. The
starter shall store all factory defaults in a preset replaceable FLASH memory chip.
2. Data Sampling
a. Critical operating data such as instantaneous current for Short Circuit, Ground
Fault and Immediate Overload calculations shall be sampled every 1 millisecond to
prevent lagging operation.
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b. Non-Critical data such as used in metering and true RMS calculations, shall be
sampled every 20 milliseconds.
3. Real Time Clock (RTC) with automatic leap-year updating shall be provided for all time
4. Battery back-up for SRAM and RTC will be a Lithium-Ion battery rated for at least 5 years
of continuous operation without power applied. The battery shall only be used when
power is not applied. Changing the battery in the field shall not affect any stored
A. Instrument Transformers: Comply with IEEE C57.13.
1. Voltage Transformers: Secondary-voltage rating of 120 V and accuracy class of 0.3 WX,
2. Current Transformers: Ratios as indicated; burden and accuracy class suitable for
connected relays, meters and instruments.
B. Multifunction Digital-Metering Monitors shall be UL-listed or UL-recognized, microprocessor-
based unit. Units shall be flush mounted on the instrument compartment door and be Siemens
Model 9300 or equal.
C. [NOTE: Select clause C if a microprocessor motor protection relay is desired in place of
the standard thermal overload protection incorporated in the solid state reduced voltage
starter module per 2.3.G.2. Motor protection device shall be:
1. The relays shall be Siemens 7SK80 protective relay or equivalent. The relay shall
provide the following protection functions: 50/51, 50N/51N, 67N, 67Ns, 50Ns,
59N/64, 37, 48, 66, 14, 51M, 49, 46, 27, 59, 81O/U, 50BF, 46, and 47.
2. The relays shall have four analog CT inputs and three voltage inputs.
3. The relays shall have five internal RTD inputs.
4. The relays shall have the option to connect 12 external RTD inputs through an
5. The relays shall provide trip circuit supervision of the feeder circuit breaker and
alarm on trip circuit failure.
6. The relays shall monitor the CT circuits and alarm on circuit failure.
7. The relays shall be capable of being used in a reverse interlocking bus protection
8. The relay shall provide logic programmability to create starting schemes for
example reduced voltage starting.
9. The relay shall provide logic programmability to create failsafe tripping logic.
10. The relays shall be capable of being used in a reverse interlocking bus protection
11. The relays shall provide demand alarms.
12. The relays shall have nine programmable function keys to replace control
13. The relays shall have programmable logic capabilities to permit use in protection
and control systems. Programming software must be compliant with IEC 1131
standard for PLC programming.
14. The relays shall have a modular communications processor to permit field change
between IEC61850, Modbus RTU, Profibus-DP, DNP3.0 and IEC60870-5-103
protocols. The relays must be able to support either RS-485 or fiber optic
15. The relays shall provide complete sequence-of-events recording, time stamped in
milliseconds. The relays shall provide oscillography (waveform) capture, with
configurable pre- and post-fault data capture times.
16. The relays shall recognize and alarm CT open circuit or short circuit conditions.
17. All relay connectors including CT connectors will be pluggable to ensure ease of
relay replacement and maintenance testing.
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18. The housing must be a sealed dust proof environment for the relay internal
electronics. Heat build up must be dissipated through the surface area of the steel
enclosure. The relay thus will maintain its tested insulation characteristic
standards per IEC, IEEE, even if deployed in harsh dusty environments.
19. The relay must provide 20 flexible functions that can be used to create additional
protection functions to maximize application flexibility.
2.6 DRAWOUT CONTROLLER ASSEMBLY
A. For 360A (up to 7.2kV), main contactor shall be drawout type, with primary current limiting fuses
mounted on the same drawout carriage. For 720A (up to 5kV) or 300A (up to 15kV), the main
contactor shall be fixed-mounted, and the primary current limiting fuses shall be mounted on a
drawout carriage, with interlocking as required between the contactor and the drawout carriage.
Each controller shall consist of a magnetically held contactor    ampere, primary
fuses for short circuit protection and to include the following:
1. Overload protection as described in paragraph 2.3.G or 2.5.C as selected above.
2. Line and load side stab fingers to allow complete removal of the drawout unit without
disconnecting the power cable. A glass polyester shutter shall automatically cover the
line side stabs when the drawout carriage is racked out.
3. Fuse assembly with minimum short circuit rating of 50 kA symmetrical. Fuses to be ANSI
Class “R” (Class “X” for 57X size) (Class E for 15kV) for motor starting duty. Fuses shall
be Siemens Type FM or A720R or approved equal. Fuses shall be mounted as an
integral part of the drawout carriage assembly. Fuse pullers shall not be required. The
operator shall not be required to reach inside the controller cubicle to remove or install
4. Vacuum interrupter main contact design shall have a minimum electrical life of 250,000
operations. Feeler gauges shall not be required to check contact wear.
5. Single phase control power transformer as specified in paragraph 2.4.E.
6. The drawout carriage shall be equipped with a set of contact fingers connected to the
CPT secondary. The contact fingers shall be arranged to ensure any load on the CPT is
disconnected prior to the main power stabs disengaging. De-energizing the secondary of
the CPT shall not depend on the operation of auxiliary contacts or cut-off switches.
7. Operating handle shall be equipped with padlock provisions.
8. The racking mechanism is to combine the following safety interlocks:
a. Prevent forward and back movement of the drawout carriage unless the contactor
is de-energized or open.
b. Prevent the opening of the high voltage compartment door unless the drawout
carriage is in the disconnect position.
c. Prevent the movement of the drawout carriage to or from the connected position
unless the high voltage compartment door is closed.
9. A test switch shall be provided to switch from run to test mode. This switch shall be
located on the back side of the low voltage door. With the contactor racked out and the
door opened, the test mode shall be selectable. It shall allow for maintenance and
operation of the main contactor and low voltage control circuitry without requiring
energizing the motor or disconnecting any load cables. An interlock shall be provided to
prevent application of test power when the contactor is racked in.
10. A control receptacle shall be furnished that connects to the pre-wired auxiliary and coil
contacts of the drawout carriage. It shall remain connected in the racked-out position to
11. Externally visible red LED indicating light, illuminated when carriage is connected to bus.
12. Low voltage compartment with door-in-door construction shall be provided to provide
access from the front.
a. Compartment to be isolated from high voltage compartments and house
components including terminal blocks, if microprocessor relays are specified in
2.4.C), and control wiring.
b. All control wiring within the assembly shall be continuous and shall terminate on
each end at a suitable terminal block. Control wiring shall be No. 14 AWG
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minimum, stranded type SIS and shall be labeled at each end with sleeve-type
c. Wire markers shall be machine imprinted with the wire name as indicated on the
d. Terminals shall be insulated locking fork or ring tongue type except where
connecting to components that do not accept these terminations.
2.7 ACCESSORIES AND SPARES
A. No special accessories such as fuse pullers, feeler gauges, etc., shall be required.
B. Supply the following:
1. Three spare power fuses of each rating
2. Two spare primary fuses for potential transformer and control power transformer
3. Spare Indicating Lights: One of each type installed
4. Touchup Paint: One-half pint of paint matching enclosure finish.
5. A recommended spare parts list, and associated pricing, will be supplied with each
different solid state reduced voltage starter. The manufacturer will provide representation
and local support to the job site. A list of authorized service centers will also be provided
PART 3 - EXECUTION
A. Examine surfaces to receive controller assemblies for compliance with installation tolerances
and other conditions affecting performance. Proceed with installation only after unsatisfactory
conditions have been corrected.
B. Install and anchor controller in accordance with manufacturer’s instructions.
C. Tighten bus joints, electrical connectors and terminals according to manufacturer's published
torque values. Install equipment grounding conductors for controller assembly with ground
continuity to main electrical ground bus.
3.2 ADJUSTMENTS AND CLEANING
A. Set field-adjustable, protective-relay trip characteristics
B. Clean exposed surfaces using manufacturer recommended materials and methods. Touchup
damaged coating and finishes using non-abrasive materials and methods recommended by
manufacturer. Eliminate all visible evidence of repair.
C. QUALITY REQUIREMENTS
D. All incoming material shall be inspected and/or tested for conformance to quality assurance.
E. Power semiconductors shall be fully tested for proper electrical characteristics (dv/dt, di/dt, etc.).
F. All subassemblies shall be inspected and/or tested for conformance to venders engineering and
quality assurance specifications.
G. Printed circuit boards shall be burned in for a minimum of 48 hours at 60°C.
H. The complete unit shall be functionally tested under load before shipment to assure proper
operation per specification. Complete test reports shall be available upon request.
A. Testing: After installing controller assemblies and after electrical circuitry has been energized,
demonstrate product capability and compliance with requirements.
1. Perform each electrical test and visual and mechanical inspection per the manufacturer’s
2. Correct malfunctioning units on-site, and retest to demonstrate compliance.
B. Perform production tests in compliance with UL and NEMA ICS requirements.
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A. Equipment manufacturer warrants that all goods supplied are free of non-conformities in
workmanship and materials. The manufacturer's warranty shall extend to at least 12 months
after initial energization, or 18 months from date of shipment from factory, whichever is first.
3.5 [STARTUP SERVICES
A. Engage a factory-authorized service representative to perform startup service.
B. Train Owner's maintenance personnel on procedures and schedules for energizing and
de-energizing, troubleshooting, servicing and maintaining equipment and schedules.
C. Verify that the controllers are installed and connected according to the Contract
D. Verify that electrical control wiring installation complies with manufacturer's submittal by
means of point-to-point continuity testing. Verify that wiring installation complies with
requirements in Division 26 Sections.
E. Complete installation and startup checks according to manufacturer's written
F. Field service: Controller assembly manufacturer’s own field service office shall be
located not more than a three hour drive from the installation site.]
END OF SECTION
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