NSI Industries STL750-4 - 4 Port Aluminum Dual Rated Transformer Connector 750 MCM - 250 MCM Transformer Connectors are made from 6061T-6 aluminum alloy. They are electro-tin plated for low contact resistance. Two NEMA 1/2" holes for easy attachment. Rated 600 volts.
NSI Industries

STL750-4

UPC: 662381097095

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Overview

NSI Industries STL750-4 is a high-strength 6061T-6 aluminum dual-rated transformer connector designed for reliable electrical connections in transformer applications. This 4-port connector accommodates conductor sizes from 750 MCM down to 250 MCM, making it ideal for both primary and secondary transformer wiring. Constructed from corrosion-resistant 6061T-6 aluminum alloy, the STL750-4 delivers superior mechanical strength and electrical conductivity while maintaining a lightweight profile compared to copper alternatives. The connector features electro-tin plating on all contact surfaces, ensuring low contact resistance and long-term reliability in high-current applications up to 600 volts. Two NEMA ½" mounting holes provide secure attachment to transformer studs or mounting surfaces, with a mounting hole spacing of 1.75 inches. The internal hex pressure screws deliver consistent clamping force, with a maximum torque rating of 8.57 inch-pounds for optimal conductor retention. Measuring 2.00 inches in length, 1.44 inches in width, and 1.125 inches in height, the STL750-4 is engineered for compact transformer installations where space is at a premium. The connector meets ANSI C119.4 Class A standards and carries a temperature rating of 90°C (AL9CU), ensuring stable performance across a wide range of operating conditions. Its dual-rated design allows use with both copper and aluminum conductors, providing flexibility in system design and maintenance. Common applications include utility transformers, pad-mounted transformers, pole-mounted transformers, and industrial power distribution systems. The STL750-4's robust construction and precise engineering make it suitable for harsh environments where vibration, thermal cycling, and mechanical stress are common concerns. With a standard packaging quantity of 3 units per carton, this connector is readily available for immediate deployment in transformer upgrade projects or new installations.
  • 6061T-6 aluminum alloy construction for superior strength and corrosion resistance
  • Electro-tin plated for low contact resistance and long-term reliability
  • Accommodates conductor sizes from 750 MCM to 250 MCM
  • Rated for 600V maximum with 90°C temperature rating
  • Two NEMA ½" mounting holes with 1.75" spacing for secure attachment

Specifications

Application
Wire Termination
Bolt Size
1/2 IN
Color
Aluminum
Environmental Conditions
90 C
Finish
Aluminum
Material
Aluminium;Aluminum
Material
Aluminum
Mounting Hole Spacing
1.75 in
Mounting Hole Spacing
44.45 mm
Mounting Hole Spacing
1.750000000000000 in
Mounting Hole Spacing
44.450000000000000 mm
Number Of Conductors
4
Number of Conductors/Ports (Main/Primary)
4
Number Of Mounting Holes
2
Number of Poles
1
Number Of Ports
4
Special Features
(4) 750-250 MCM - Dual Rated - 3 Pack
Temperature Rating, Maximum
194.00000 F
Temperature Rating, Maximum
90 °C
Temperature Rating, Maximum
194 F
Temperature Rating, Maximum
90 C
Temperature Rating, Minimum
194.00000 F
Temperature Rating, Minimum
90 °C
Temperature Rating, Minimum
194 F
Temperature Rating, Minimum
90 C
Type
Transformer Lug
Voltage Rating
600 V
Warranty
1 Year
Package Dimensions (L x W x H)
8.57 IN x 1.44 IN x 2 IN
Package Dimensions (L x W x H)
21.7678 cm x 3.6576 cm x 5.08 cm
Package Weight (Imperial)
3.990 L
Package Weight (Metric)
1.810 kg
6 Port Aluminum Dual Rated Transformer Connector 750 MCM - 250 MCM Transformer Connectors are made from 6061T-6 aluminum alloy. They are electro-tin plated for low contact resistance. Two NEMA 1/2" holes for easy attachment. Rated 600 volts.

STL750-6

6 Port Aluminum Dual Rated Transformer Connector 750 MCM - 250 MCM Transformer Connectors are made from 6061T-6 aluminum alloy. They are electro-tin plated for low contact resistance. Two NEMA 1/2" holes for easy attachment. Rated 600 volts.
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TL500-4L2

Cast Bronze Terminal Lug 500 - 300 MCM 4 Port 2 Mounting Holes Copper Terminal Lugs are made of high copper alloy. They are used for joining a wide range of cables or terminal blocks.
Aluminum Splicer Reducer 2-14 AWG Aluminum Splicer Reducers are used for splicing two copper or aluminum wires of equal or different sizes. Made of 6061T-6 aluminum alloy. Electro-tin plated for low contact resistance. Suitable for use with both copper and aluminum conductors. Rated 600 volts (2000V max. per UL486B). UL 486A/B Listed. Temperature rating 90 degrees C.

2SR

Aluminum Splicer Reducer 2-14 AWG Aluminum Splicer Reducers are used for splicing two copper or aluminum wires of equal or different sizes. Made of 6061T-6 aluminum alloy. Electro-tin plated for low contact resistance. Suitable for use with both copper and aluminum conductors. Rated 600 volts (2000V max. per UL486B). UL 486A/B Listed. Temperature rating 90 degrees C.
1 Port Double Screw Panelboard Lug 1500 MCM - 1000 MCM Panelboard Lugs are large size set screw connectors with multiple mounting holes for a secure, turn-prevent connection. Made of 6061T-6 aluminum alloy. Tin plated for low contact resistance. Suitable for use with both copper and aluminum conductors. Rated 600 volts. Mounting hole spacing is 1 3/4" from center to center.

1500LL2

1 Port Double Screw Panelboard Lug 1500 MCM - 1000 MCM Panelboard Lugs are large size set screw connectors with multiple mounting holes for a secure, turn-prevent connection. Made of 6061T-6 aluminum alloy. Tin plated for low contact resistance. Suitable for use with both copper and aluminum conductors. Rated 600 volts. Mounting hole spacing is 1 3/4" from center to center.
1 Port Panelboard Lug 350 MCM - 6 AWG Panelboard style for multi-conductor with NEMA mounting hole spacing for turn prevent and secureness. Made of 6061T-6 aluminum alloy. Electro-tin plated for low contact resistance. For use with copper or aluminum conductors. Rated 600 volts (2000V max per UL486B). UL 486A/B Listed. Temperature rating 90 degrees C. All hole spacing is NEMA standard of 1.750".

350L2

1 Port Panelboard Lug 350 MCM - 6 AWG Panelboard style for multi-conductor with NEMA mounting hole spacing for turn prevent and secureness. Made of 6061T-6 aluminum alloy. Electro-tin plated for low contact resistance. For use with copper or aluminum conductors. Rated 600 volts (2000V max per UL486B). UL 486A/B Listed. Temperature rating 90 degrees C. All hole spacing is NEMA standard of 1.750".

Frequently Asked Questions about NSI Industries

What technical support does NSi Industries offer?

NSi Industries offers dedicated technical support through their toll-free technical support line at 888.500.4598. They are committed to customer satisfaction and promise to make every reasonable effort to remedy any product or service issues. Additionally, customers can contact their customer service team at 800.321.5847 or email [email protected] for further technical assistance.

What are the key features of NSi Industries products?

NSi Industries products feature exceptional versatility, reliability, and safety across multiple industrial automation categories. Key features include insulation piercing connectors with no wire stripping required, watertight and corrosion-free designs, wide wire range compatibility (from #14 AWG to 750 MCM), and the ability to install on energized conductors. Their product lines like Easy-Tap™ Connectors and TORK® Digital Timers demonstrate advanced capabilities such as turbo spacers, double shear-head bolts, astronomic scheduling, and enhanced switching technologies.

What environmental ratings do NSi Industries products have?

NSi Industries enclosures feature robust environmental ratings, including IEC 60529 IP66 certification, NEMA Type 1, 2, 3, 4, 4X, 12, and 13 ratings, and UL/CSA standards. Their products are designed for both indoor and outdoor applications, with protection against dust, water, corrosion, and extreme temperatures ranging from -40°F to 266°F.

How are NSi Industries products typically installed?

NSi Industries products are typically installed using detailed mechanical and digital wiring diagrams that specify precise connection methods for various voltage configurations (120V, 208V, 240V, 277V, 480V). Installation involves carefully following product-specific wiring schematics, which include clear terminal block connections, ground wire specifications, and phase alignment requirements. Professional electricians and technicians should reference the specific product's wiring diagram to ensure correct installation and electrical compliance.

What industries and applications are NSi Industries products used for?

NSi Industries provides electrical and automation products for diverse industrial applications, including lighting control, electrical enclosures, wire management, connectors, and sensor technologies. Their product lines serve commercial, industrial, and infrastructure markets with solutions for electrical infrastructure, control systems, and safety-critical environments.

What are the main product lines offered by NSi Industries?

NSi Industries offers a comprehensive range of industrial products including TORK® Photocontrols, Polaris™ Lighting Controls, Easy-Twist™ Grounding Solutions, Miniterms, Cable Ties, Connectors, Enclosures, Occupancy Sensors, and Wire Management systems. Their product lines span electrical components, control devices, and industrial automation accessories designed for diverse applications in commercial and industrial settings.

What accessories are available for NSi Industries products?

NSi Industries offers a range of accessories for their product lines, including photocontrol accessories like replacement caps, mounting brackets, and receptacles. Specific accessories include shorting caps, open caps, 3-pin and 7-pin receptacles, and utility mounting brackets for conduit photocontrols. For specialized applications, NSi recommends contacting their customer service team to discuss custom accessory needs.