Section 13 — Electrical

NEMA 3R, 4X, 4/7 Combination Motor Starters and Circuit Breakers with Enclosure

IPE Engineering Practice IPE-EP-13-7-2

Document number: IPE-EP-13-7-2 · Section: 13 — Electrical

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SCOPE

This Practice including the Data Sheet for NEMA 3R, 4X and 7 combination motor starters and circuit breakers covers the requirements for the subject NEMA general purpose 3R and 4X units and NEMA 7 classified area devices for both individual units and units specified as part of a 480 volt prefabricated switchrack (EP 13–1–1).

This Practice is appropriate for attachment to an inquiry or purchase document when accompanied by the referenced IPE Engineering Practices and completed Data Sheets.

Any deviation to this Practice shall be in accordance with the procedure given in EP 1–1–3.

An Asterisk (*) indicates that a decision by the Owner’s Engineer or Owner is required, or that additional information is furnished by the Purchaser.

REFERENCES

The latest edition of the following standards and publications are referred to herein.

STANDARDS AND PUBLICATIONS

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DEFINITIONS

Contractor – Company or business that agrees to furnish materials or perform specified services at a specified price and/or rate to the Owner.

Inspector – A Inflection Point Engineering, LLC appointed engineer or inspector.

Manufacturer - The recipient of a direct or indirect purchase order for materials and/or equipment. In this context, a direct order is one issued to a Manufacturer by a Contractor or the Owner. An indirect order is one issued to a Manufacturer by a vendor (recipient of a direct order) for materials, fabricated components, or subassemblies.

Owner – Inflection Point Engineering, LLC.

Owner’s Engineer – A Inflection Point Engineering, LLC. appointed engineer.

Purchaser – The party placing a direct purchase order. The Purchaser is the Owner’s designated representative.

SERVICE CONDITIONS

Equipment shall be designed to operate outdoors in a typical petro–chemical plant environment, without derating, with ambient temperatures at a 104 ºF maximum and –15 ºF minimum at an altitude of 3,300 feet or lower. The Data Sheet identifies any special conditions known to exist at the application location.

DESIGN CONSTRUCTION AND MATERIALS

General

All NEMA 4X and 7 enclosures external (exposed) bolts, screws or other hardware shall be Series 300 stainless steel. All covers shall be hinged and all cover bolts shall be captive.

All internal component mounting metal pans shall be painted or galvanized to reduce corrosion.

NEMA 4X and 7 enclosure breaker shafts and operators shall be stainless steel with stainless steel inserts.

All control equipment shall be NEMA rated.

All components (control equipment) shall be listed and suitable for the specified application. Enclosure breathers/drains shall be provided when specified on the Data Sheet.

Enclosures

NEMA 3R Enclosures

• Enclosures shall meet the requirements of NEMA 3R enclosures with type test results available to prove quality and ability to meet NEMA 3R requirements.
• Enclosures shall be coated internally and externally with a high quality epoxy paint.
• Enclosures shall be listed for the specific application.

• NEMA 4X Enclosures
• Enclosures shall meet the requirements of NEMA 4X with type test results available to prove quality and ability to meet NEMA 4X requirements.
• Enclosures shall be stainless steel.
• NEMA 4/7 Enclosures
• All NEMA 7 enclosures for combination starters and circuit breakers shall be rated NEMA 4/7 and meet all the requirements of both NEMA 7 and NEMA 4.
• All NEMA 4 and 7 combination motor starter and circuit breaker enclosures shall be UL listed or UL classified and suitable for use with systems having 25,000 RMS symmetrical ampere fault current available and shall indicate such on the enclosures nameplate (UL standard 1203 and UL subject 2063).
• All enclosures shall be cast copper free aluminum, with a maximum copper content of 4/10 of one percent.
• Enclosures shall be epoxy coated both externally and internally to reduce corrosion.
• All enclosures shall be equipped with breathers and drains suitable for the specified classified area.
• External operation handle operators shall have adjustable mechanical stops to limit handle travel to prevent damage to internal circuit breaker operator paddles.
• Combination Motor Starters
• The minimum size starter shall be NEMA size 1.
• Combination motor starters shall be suitable for use on systems with 25,000 RMS symmetrical ampere available fault current. Any requirement for higher AIC shall be indicated on the Data Sheet.
• All combination motor starters shall be provided with three thermal overload devices (one per phase) as follows:
• Minimum adjustment range of 90 to 110% of heater range.
• Ambient compensated.
• Manually resettable, with a front panel/door reset push button. Reset push button shaft shall be stainless steel.
• Overload relays with heater elements shall be sized for 115% of motor full load current for

1.0 SF motors and 125% for 1.15 SF motors.

• Combination motor starter main disconnect and fault clearing device shall be provided as specified below and on the Data Sheet, EP 13–7–2DS.
• Fused switch
• The switch shall be a three pole gang operated, non–load break, quick make/quick break switch. Fuses shall be sized for fault protection only with motor overload protection provided via separate thermal overload devices.
• When a fused switch is provided, a local “run–off” maintained position switch shall be provided to shutoff the attached motor load at the starter location. The run position shall not start the motor, but will enable the Owner’s remote start.

• Molded case circuit breaker; magnetic only motor circuit protector (MCP)
• The MCP shall have an adjustable magnetic trip unit properly sized to meet the NEC requirement of a maximum setting of 13 times motor full load amps and be designed to avoid nuisance tripping from motor starting inrush current.
• The minimum frame size shall be 100 ampere.
• Molded case circuit breaker––thermal magnetic
• The breaker shall have an adjustable instantaneous (magnetic) element. The thermal and instantaneous (magnetic) function shall be selected or adjustable to limits allowed by the NEC and have suitable time current characteristics to avoid nuisance tripping for motor starting inrush currents.
• Minimum frame size shall be 100 ampere.
• Electronic trip (solid state) molded case circuit breaker.
• The breaker shall be a non–drawout breaker with adjustable long–time, short time and instantaneous functions.
• The breaker shall have interchangeable breaker ampere rating plugs.
• Minimum frame size shall be 100 ampere.
• Control voltage shall be 120 VAC, unless specified otherwise on the Data Sheet.
• 480/120 volt control transformers shall have two primary fuses and a single secondary fuse with the unfused leg grounded. Unless specified otherwise, the minimum control power transformer size (VA) shall be as indicated in Table 1.
• The starter internal power wiring and circuit breaker line side wiring shall be suitable for the maximum horsepower rating of the starter. The minimum power wire size shall be as shown in Table 2. The power wire shall be stranded copper wire with XHHW, XHHW2 or RHW-2(EPR) insulation rated 600 volts to ground.
• Internal control wiring shall be a minimum of #12 AWG stranded copper wire with XHHW, XHHW2, or SIS insulation rated 600 volts to ground.
• The combination starter internal component Manufacturer shall be as specified on the Data Sheet. This shall include molded case breakers, contactors (starters) control transformers, motor overloads and control relays.
• Terminal block provisions shall be provided to terminate an NEC sized, incoming power source ground wire, and for the Owner’s outgoing load side NEC sized ground wire to be run with load phase conductors. Also insure that the enclosure has provisions for an internal ground termination point for the Owner’s power supply ground.
• All combination starters in NEMA 3R, 4X, 7 enclosures shall be equipped with a 120 VAC space heaters, 25 watt minimum rating. The space heater shall be wired to a terminal block to allow normal power source wire removal and connection of the Owner’s temporary external 120 VAC power source during storage. The space heater shall be controlled by an auxiliary contact on the main contactor that will energize the space heater with the motor not running and de– energize the space heater with the motor running.
• Combination starter breaker/disconnect handles shall be padlockable in the “off” position, and shall be self aligning with the disconnect device handle/operator.

• When specified, a combination motor starter shall be equipped with an undervoltage time–delay dropout motor reacceleration circuit. The dropout time shall be adjustable from 0–5 seconds. Terminal block jumper wires shall be provided to remove the undervoltage restart scheme from service. The time delay relay shall be an Agastat 7022 series relay, or as specified on the Data Sheets.
• Circuit Breaker and Enclosure Assemblies
• External operating handle shall:
• Be lockable in the “off” position.
• Be self aligning with the circuit breaker handle.
• Circuit breakers rated at 480 volt shall have a 25000 AIC and 120 Volt circuit breakers shall have a 10,000 AIC. Any requirement for higher AIC shall be indicated on the Data Sheet.
• Circuit breaker assemblies identified for use as 120 VAC receptacle feeders shall have 20 amp GFCI circuit breakers.
• As a minimum all complete enclosure/circuit breaker assemblies shall be UL listed or UL Classified for 25,000 RMS symmetrical ampere.
• Circuit breaker Manufacturers shall be as specified on the Data Sheet.
• Nameplates
• Each enclosure shall have a permanent nameplate. Nameplates shall be laminated plastic, with black 3/8 inch high lettering on a white background. Text shall be as indicated on the Data Sheet.
• Nameplates shall be secured with stainless steel screws.
• Control Switches, Pushbuttons and Indicating Lights
• General purpose (unclassified areas)
• All pushbuttons, control switches and indicating lights shall be industrial grade, heavy duty, oil tight/water tight (UL types 4, 13/NEMA types 4, 4X, 13).
• All indicating lights shall be 120 VAC push–to–test.
• All devices shall be UL listed.
• Classified areas
• All control devices shall be heavy duty, oil tight/water tight NEMA rated and suitable for the classified area specified.
• All devices shall be UL listed.

DRAWING AND DATA REQUIREMENTS

All drawings provided shall show the equipment as specified and/or ordered. Typical drawings are not acceptable, unless they are revised to show the equipment being furnished. Drawings shall be supplied in the quantities shown on the Data Sheet.

• Information to be supplied with the quotation shall be as indicated on the Data Sheet, EP 13-7- 2DS.
• Information to be Submitted After Receipt of Order

• All the information requested on the Data Sheet, EP 13-7-2DS and conformed to the order documents.
• Detailed list of nameplates.
• Spare parts listing with prices.
• Certified Information to be Supplied
• All the information on the Data Sheet, EP 13-7-2DS.
• Installation, maintenance and operating instructions. Installation, maintenance and operating instructions shall cover all the equipment furnished including all protective devices, auxiliary relays and coordination curves of each protective device.

7.0 SHIPPING

“Preparation for Shipment” shall be in accordance with Manufacturer’s standards, unless otherwise noted on the “Request for Quotation” and/or “Purchase Order”. The Manufacturer shall be solely responsible for the adequacy of the “Preparation for Shipment” provisions employed in respect of materials and application, to provide materials to their destination in ex– works condition when handled by commercial carrier systems.

8.0 TABLES

TABLE 1

MINIMUM WIRE SIZES FOR POWER CIRCUITS

TABLE 2

STANDARD CONTROL POWER TRANSFORMER SIZE (480/120 VOLT TRANSFORMERS)

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