SIMOVAC non-arc-resistant and SIMOVAC-AR arc-resistant motor controllers

Features include:

• SIMOVAC-AR tested for arc-resistance to IEEE C37.20.7, type 2B
• Complies with UL 347 6th edition (same as CSA C22.2 No. 253-09) (UL / cUL Listing not available on 720 A SSRVS controller)
• 400 A bolt-in or stab-in (optional) or 720 A bolt-in vacuum contactor
• 400 A or 720 A non-load-break isolation switch
• 2.4 kV, 4.16 kV and 6.9 kV (up to 7.65 kV) system voltage ratings
• 1,200 A, 2,000 A, 3,000 A or 4,000 A main bus with standard epoxy insulation on bus bars, and with optional boots for insulating joints
• Tin- or silver-plated bus available
• Front accessible
• Main bus and ground bus are supported and braced to 63 kA two-second short-time capability
• Top-mounted pressure relief channel shipped installed for reduced site installation time
• Isolation switch with visible indication through viewing window to verify that the power cell is isolated from line-side source ‒ no need to open panel door
• Isolation switch mechanically interlocked with the access door to prevent user access to primary compartment when isolation switch is closed
• Low-voltage compartment is isolated from the medium-voltage compartment
• All components are front accessible, facilitating routine inspection or parts replacement
• Current-limiting fuses, contactor assembly and isolating switch assembly are easily removed from the enclosure
• The main bus compartment is top, side and front accessible for easy installation and extension.

Medium-voltage motor controllers are available as:

• Type 1 non-gasketed
• Type 1 gasketed (rear panels only)
• Type 2 drip resistant (SIMOVAC non-arc-resistant only)
• Type 3R (SIMOVAC non-arc-resistant only)
• Type 12 dust tight (SIMOVAC non-arc-resistant only).

Features and benefits

Siemens SIERS integrated electrical isolation switch operating system provides additional personnel protection against arc-flash exposure for operators by providing a means of remotely operating the non-load disconnect between the ON and OFF position for Siemens SIMOVAC non-arc-resistant and SIMOVAC-AR arc-resistant medium-voltage controllers.

Type SIERS for SIMOVAC and SIMOVAC-AR delivers a safe, easy-to-use, cost-effective, reliable and flexible way to remotely operate the non-load isolation switch while standing outside of the arc-flash zone. This reduces the need for personal protective equipment (PPE) per the NFPA-70E® standard.

Standard features:

• Maintains all of the safety interlocks as required by UL 347 and CSA 22.2 No. 253
• If interference is experienced while closing the non-load  isolation switch, the SIERS system will attempt to return to the OFF position
• The control pendant (hand-held controller) is the same as used for GM-SG or GM-SG-AR metal-clad switchgear and provides clear light-emitting diode indication of the position of the non-load isolation switch in the ON (CONNECT) and OFF (DISCONNECT) positions
• When plugged into a specific controller compartment, the control  pendant will override any electronic control system (HMI, SCADA or similar)
• User-friendly control pendant with easy to read display and controls
• Provisions for energizing SIERS with an external 120 Vac power supply with an extension cord (optional)
• The fixed-mounted motor integrated in the controller compartment provides smooth and efficient movement of the non-load isolation switch between the OFF position and the ON position
• Logic to sense interference issue during open and close operations when moving from ON to OFF or vice-versa
• Operation is smooth and consistent
• Control pendant is industrial class
• Factory installed and tested as an integrated remote switch operating system
• Powered by stationary-mounted distribution transformer located in the controller lineup or powered from a 120 Vac or 125 Vdc external source
• Controls can be integrated into the switchgear secondary control circuits interface with the protection relay to provide interface with SCADA systems, local HMI or discrete wiring
• Available as a field retrofit for existing Siemens types 
• SIMOVAC and SIMOVAC-AR medium-voltage motor controllers
• Lineups of SIMOVAC and GM-SG non-arc-resistant or SIMOVAC-AR and GM-SG-AR arc-resistant equipment can be furnished with SIERS.

Optional configurations:

Type SIERS device is available in three configurations:

• Basic version
• Local HMI version (Sm@rtGear™ power distribution solution)
• Custom version (i.e., SCADA or other system).

Intelligent devices (circuit breakers, relays, meters, etc.) have existed for more than 30 years. These devices are self-monitoring, configurable, and communicating, but individually they are only islands of intelligence. Historically integrated remote monitoring, configuration, and control have only been available with the inclusion of upstream PMCS, PCS, DCS, or SCADA systems.

With the advent of Siemens Sma@rtGear technology, remote monitoring, configuration, and control are standard features that are integral to the electrical apparatus product.

Advantages at a glance:

• Keeping business operational with maximum uptime
• Reliable energy-efficient products and systems
• Ease of operation and maintenance
• Remote access for arc-flash mitigation
• Integration with existing equipment
• One supplier for all power distribution needs
• Long-term partner over entire lifecycle
• Technology leader with durable solutions
• 24/7 hotline support.

Sm@rtGear features, benefits and details for medium-voltage controllers:

• Types: 12SVC400, 12SVC800 contactors
• Maintenance mode: yes
• Metering: Q200, Q100, P855
• Protective relays: Yes, standard Siemens SIPROTEC
• Remote racking: No
• Remote open/close: Yes
• HMI size: 22"
• Auto-throwover: Yes
• Temperature sensing: Yes
• Optional accessories: High-resistance grounding, partial-discharge monitoring.

For more information about the entire Sm@rtGear portfolio for low- and medium-voltage power distribution equipment, please go to Sm@rtGear™ power distribution solution.

• No. 13 - Use of latched contactors to switch transformers
• No. 15 - Expected life of electrical equipment
• No. 16 - Bus joint fundamentals
• No. 17 - Main bus continuous current rating
• No. 18 - Bus joint and primary disconnect plating
• No. 19 - Bus joint current density
• No. 20 - Power factor correction capacitor - sizing for motors
• No. 26 - Ground bus ratings
  
• No. 33 - Clearance requirements in switchgear and control equipment
  
• No. 42 - Circuit breakers or vacuum contactors - application considerations
  
• No. 45 - Accuracy of current transformers (CTs) used in medium-voltage control equipment
  
• No. 46 - Selection of current transformer (CT) ratio in medium-voltage control
• No. 47 - 7.2 kV equipment basic insulation levels (BIL)
• No. 57 - Arc-flash hazard labels
  
• No. 58 - What is the difference between E-rated and R-rated current-limiting fuses?
• No. 70 - Arc-resistant switchgear accessibility types
• No. 79 - Working space required around electrical equipment
  
• No. 81 - Arc-flash incident energy mitigation
• No. 82 - Continuous current capability in ambient temperatures other than 40 °C
• No. 84 - Space heater - sizing and application principles
  
• No. 85 - Temperature limitations for user’s power cables
• No. 86 - Use of unshielded cables for connections in medium-voltage switchgear and motor controllers
• No. 88 - Application of maintenance grounds in switchgear
  
• No. 89 - Venting of exhaust gases from arc-resistant equipment
  
• No. 90 - Temperature ratings for external cables
• No. 92 - Heat generation estimation for SIMOVAC non-arc-resistant and SIMOVAC-AR arc-resistant medium-voltage controllers
• No. 100 - Third-party listing - UL, C-UL and CSA
  
• No. 102 - Tapered bus
  
• No. 103 - Medium-voltage controllers - fixed-mounted contactors compared to drawout contactors
• No. 104 - Arc-resistant equipment - sealing requirements
• No. 105 - Fuses and overload protection for motor starting with class E2 controllers
• No. 106 - Arc-resistant equipment - exit of exhaust plenum from buildings
• No. 108 - Lightning-impulse (BIL) ratings for medium-voltage controllers
  
• No. 110 - Corrosion prevention effects on electrical equipment life
• No. 112 - Use of R-rated fuses in lieu of E-rated fuses for transformers
• No. 114 - Low-ratio current transformers in medium-voltage controllers
• No. 115 - Third-party listing/labeling and recognition
  
• No. 116 - Arc-resistant switchgear ‒ accessibility type C
• No. 118 - Bolted construction vs. welded construction
  
• No. 119 - Momentary ratings – peak or rms?
  
• No. 120 - High-potential testing – current doesn’t matter!
  
• No. 122 - Current transformer thermal-rating factor
  
• No. 125 - Do not connect surge arresters or capacitors on the load side of solid-state, reduced-voltage (SSRVS) controllers
• No. 126 - Testing of vacuum interrupters with dc test sets
• No. 133 - Motor starting: autotransformer or soft starter?
• Entire TechTopics catalog

The type SIMOVAC-AR equipment is classified as arc-resistant, as defined in ANSI/IEEE C37.20.7, and has been qualified in tests to carry a type 2B accessibility rating. These arc-resistant features provide an additional degree of protection to personnel in close proximity to the equipment in the event of an internal arcing fault while the equipment is operating under normal conditions. The enclosure withstands the pressures and elevated temperatures of an internal arcing fault and directs the hot gases and arc by-products into the top-mounted pressure relief channel (PRC). These arc by-products are then vented to the outside environment through an exhaust duct or plenum system. The exhaust plenum (duct) must be routed to an area where personnel will not be present when the equipment is energized. 

The exhaust plenum (or duct) is provided separately, in modular shipping lengths (normally 36” (914 mm) long), and the shipping lengths are easily installed and connected together at the site.

In cases where a transition section is used to close couple SIMOVAC-AR controllers to Siemens type GM-SG-AR medium-voltage switchgear, the hot gases and burning particulates are directly exhausted into a common PRC for both SIMOVAC-AR controllers and GM-SG-AR switchgear, before being vented to the outside through a common exhaust plenum. One of the images to the right presents an exhaust plenum for a SIMOVAC-AR lineup and for a SIMOVAC-AR section connected to type GM-SG-AR switchgear section with a transition section. This figure depicts the exhaust plenum connected to the front, but the plenum may be connected to either side or to the rear, or to the top of the PRC.

Enclosures used to couple type SIMOVAC-AR controllers to other equipment (for example, transition sections, transformer throats, bus ducts, etc.) as well as specialized vertical sections within a lineup of type SIMOVAC-AR equipment that have not been qualified for resistance to internal arcing are not considered to be arc-resistant.

Reduced-voltage, autotransformer, non-reversing controller in addition to Siemens solid- state, reduced-voltage (SSRV) controller consists of a main vacuum contactor, run vacuum contactor, starting vacuum contactor, and an autotransformer.  

This traditional electro-mechanical  approach to starting medium-voltage motors is rated for NEMA medium-duty applications. The simplified reduced-voltage starting method has been used for years and is highly familiar to users.  

Motor data must be provided when ordering to ensure that the autotransformer is sized properly.

Benefits of RVAT starting:

•  Reduced torque shock damage on motor and driven load
•  Increased motor and drive train reliability
•  50%, 65%, and 80% tap settings allow for flexible starting characteristics
•  Easy to maintain
•  Reduced hydraulic/mechanical problems
•  Low-current starting limitations
•  Increase starting torque
•  More experienced maintenance personnel available.

Starting characteristics 

The various taps on the autotransformer provide the option for different starting voltages. Higher voltage taps are used for applications that require high-starting torque, or to limit the accelerating period within the duty-cycle rating of the autotransformer. Controllers are normally set to the 65-percent voltage tap when they leave the factory.

Solid-state reduced-voltage starter (SSRVS) controller consists of a main contactor, a silicon controller rectifier (SCR) chassis and a bypass contactor (rated for full-voltage starting). 

The SSRVS controller provides the most flexible starting options, offering selectable current or voltage ramps. For emergency full-voltage starting, the bypass contactor can be used as an across-the-line starter by changing a control switch position. 

As an option, the starter can be equipped with a permanent emergency across-the-line starting option including an additional set of current transformers (CTs), normal/emergency selector switch and a bimetallic overload relay. Repositioning power cables for this option is not required.

Benefits of SSRV starting:

•  Reduced torque shock damage on motor and driven load
•  Increased motor and drive train reliability
•  Starting kVA limitation
•  Maintains future system flexibility
•  Soft-start and soft-stop (for pumps) to control water hammer
•  Reduced hydraulic/mechanical problems.

SCR logic control

The SCR logic control incorporates the following standard protection, metering and parameter adjustments:

• Initial voltage (0 to 50 percent nominal voltage; 0 to 80 percent using extended setting)
• Current limit (100 to 400 percent of motor FLA standard; 100 to 700 percent using extended setting). Please contact Siemens representative for setting below 300 percent
• Overcurrent rating (400 percent - 30 seconds)
• Acceleration time (1 to 30 seconds standard; 1 to 90 seconds using extended setting)
• Deceleration time (0 to 30 seconds; 0 to 90 seconds using extended setting)
• Decel-final torque (0 to 10 percent sensitivity)
• Pump control - in addition to the standard start curve and torque curve, there are three selectable pump control curves and stop curves
• Pulse (kick) start (for pulse time less than 1 second, 70 to 700 percent of full-load amperes (FLA); for pulse time greater than 1 to 10 seconds, 70 to 400 percent of FLA)
• Undervoltage trip (50 to 90 percent, adjustable trip delay)
• Overvoltage trip (110 to 125 percent, adjustable trip delay 1 to 10 seconds)
• Undercurrent (load-loss) trip (0 percent equals off, 20 to 90 percent of motor FLA with adjustable trip delay adjustable from 1 to 40 seconds)
• Allowable restarts (0 to 10, adjustable time inhibit)
• Electronic overload (inverse time, two-stage programmable class 5 to 30); choose from either IEC or NEMA overload curves
• Electronic shear pin (100 to 850 percent of motor FLA with adjustable trip delay of 0 to 5 seconds)
• Phase loss (one or more phases missing with phase loss auto-reset feature)
• Shorted SCR (internal fault detected, operational after the start signal is initiated)
• Wrong connection (internal fault/motor connection, operational after the start signal is initiated)
• Starter over temperature (heat sink over temperature). Thermal sensors mounted on the heat sinks. Trips the starter when heat sink temperature rises above 185 °F (85 °C)
• Elapsed time meter, displays the motor total run time
• Time since last start
• Last start maximum current
• Starting time for last start
• Total number of starts
• Cause of last start
• Percentage of current at last trip
• Total number of trips
• RS 485 with Modbus remote terminal unit protocol (optional Profibus DO available)
• Opto-isolated inputs
• Number of relay outputs (3 form C)
• Analog output (programmable as 0-10 Vdc, or 4-20 mA, or 0-20 mA)
• Display (alphanumeric liquid-crystal display (LCD) - 2 lines x 16 characters)
• Non-volatile memory for programming and faults
• Programmable in four languages
• Residual ground-fault protection.

The photo to the right shows the manually operated, single-throw, gang-operated load-interrupter switch available in types SIMOVAC and SIMOVAC-AR assemblies, rated either 600 A or 1,200 A. Quick-make, quick-break arcing blades combined with arc chutes provides positive, three-phase interruption of load currents. The switch uses a quick make/quick break stored-energy operator. The load-interrupter switch may be unfused or equipped with current-limiting fuses to provide short-circuit current interrupting capacity. Fuses are mounted below the switch. The table below shows the ratings for the load-interrupter switch. 

The door and switch operating handle are mechanically interlocked to ensure the door cannot be opened with the switch closed and the switch cannot be closed with the door open. In addition, the switch is covered with a Lexan barrier. The switches are fixed mounted and can be equipped with fixed-mounted fuses. 600 A load-interrupter switches, whether fused or non-fused, fit in a full height 36” (914 mm) wide section. 

1,200 A load-interrupter switches, whether fused or non-fused, require a full-height 48” (1,218 mm) wide section.

Optional accessories for the load-interrupter switches include auxiliary contacts (2 NO and 2 NC) or blown fuse indicator.