Power-Zone™ 4

Class 6037 / Refer to Catalog 6037CT9901

Power-Zone™ 4 Low Voltage Switchgear with MasterPact™ MTZ or NW/NT Circuit Breakers

Power-Zone 4

Low Voltage Switchgear with MasterPact MTZ Circuit Breakers

(Class 6037)

Power-Zone 4

Low Voltage Switchgear with MasterPact NW Circuit Breakers

(Class 6037)

Power-Zone 4

Front Accessible Low Voltage Switchgear

(Class 6037)


Shown with MasterPact MTZ circuit breakers. MasterPact NW circuit breakers are also available.

Square D™ brand Power-Zone™ 4 low voltage, metal-enclosed, drawout switchgear is designed to provide superior electrical distribution, protection, and power quality management. The prime components of the switchgear are the MasterPact™ ANSI rated circuit breaker. Power-Zone 4 switchgear is designed to maximize the functionality of the MasterPact circuit breakers, which, in turn, deliver maximum uptime, system selectivity, ease of maintenance, and reliable circuit protection. All of these features are packed into the smallest footprint available for low voltage drawout switchgear.

  • Power-Zone 4 is designed and built to ANSI® C37.20.1 and is Listed to UL 1558

  • MasterPact MTZ, NW and NT drawout low voltage power circuit breakers are designed and built to ANSI C37.13 and C37.16. Listed to UL 1066

  • Short-circuit current rating up to 200 kA at 240 V and 480 V without fuses

  • High short-time withstand ratings up to 100 kA for 1 second, minimum

  • Arc flash limiting (L1F) MasterPact MTZ2 or NW feeder breakers available in 800, 1600, and 2000 A ratings

  • Family of field installable and upgradeable MicroLogic™ trip units with optional EcoStruxure Power™ data communications features

  • Power-Zone 4 switchgear can offer optional factory integrated data communications capability with Ethernet (Modbus TCP/IP) connectivity to EcoStruxure Power Edge Control or Asset Management software

  • Smallest equipment footprint available in this product class

  • Front access to all control and communications wire connections

  • Bolted copper bus provided as standard (up to 6000 A maximum)

  • Large rear cable compartment pull area allowing maximum room for power cables

  • Horizontal bus provision for future equipment expansion

  • System designed for maximum uptime with low maintenance

  • Modular circuit breaker designed for easy addition of control accessories

  • Available in NEMA 3R outdoor walk-in enclosures

  • Available in 42" deep, front accessible only version for greater layout flexibility and optimized electrical house footprint

  • Available Arc Resistant construction certified to ANSI C37.20.7. See Power-Zone™ 4 Arc Resistant Switchgear with ArcBlok Technology.

MasterPact MTZ2, 3 or NW circuit breakers are available in various levels of interrupting ratings from 42–200 kA at 480 V and 130 kA at 600 V.

The MasterPact MTZ1 or NT circuit breaker is available in an 800 A frame size and 42 kA at 480 V interrupting rating. Up to 8 MasterPact MTZ1 or NT circuit breakers can be mounted in a 30-inch wide section. (Not available for 600 V.)

Circuit breakers of like frame sizes and interrupting ratings are interchangeable.

Equipment Ratings

Application Voltage Systems


600 Vac Maximum

1600 A–6000 A
(Main circuit breaker or main lugs only)

1Ø3W, 3Ø3W, 3Ø4W

50/60 Hz

Short-Circuit Current Ratings

Withstand Ratings

240 V

480 V

600 V

42 kA

42 kA

42 kA

42 kA

65 kA

65 kA

65 kA

65 kA

85 kA

85 kA

85 kA

85 kA

200 kA

200 kA

130 kA

100 kA (maximum)

Power-Zone™ 4 Arc Resistant Switchgear with ArcBlok Technology

Arc Resistant Power-Zone 4

Low Voltage Switchgear

(Class 6037)


Shown with MasterPact NW ArcBlok circuit breakers. MasterPact MTZ2,3 ArcBlok circuit breakers are also available.

Protecting Your Personnel and Equipment from an Arc Flash

Power-Zone 4 arc resistant switchgear with MasterPact ArcBlok technology offers patented, superior arc flash protection for operators and maintenance personnel. The arc flash containment features are unique to the industry in both the circuit breaker compartment and the structure.

Power-Zone 4 Arc Resistant Switchgear with ArcBlok Technology is certified to comply with ANSI C37.20.7 IEEE Guide for Testing Metal-Enclosed Switchgear Rated Up to 38 kV for Internal Arcing Faults, and third-party (UL) witnessed as arc resistant switchgear. Refer to Data Bulletin 6037DB1302 for the complete UL Witness Certification Summary.


  • MasterPact MTZ2, 3/NW circuit breakers with patented ArcBlok technology (up to 5000 A)

  • Rated for systems with up to 100kA, 635V fault current

  • 60 in. deep x 22 in. wide (smallest arc resistant footprint in the industry)

  • 22 in., 36 in. section widths

  • 60 in., 72 in., 80 in. section depths

  • Internal arc gas management system for optimized cooling

  • ANSI Type 2B Rating

  • NEMA 1 enclosure

Available Options

  • Insulated copper bus

  • Zone selective interlocking

  • High-resistance grounding

  • Energy reduction maintenance switch

  • Section barriers (rear, cable, and side)

  • Circuit breaker remote racking

  • ANSI Type 2B rated arc plenum exhaust

Built on the Legendary Performance and Reliability of the MasterPact Line

MasterPact MTZ circuit breakers prepare you for the future of power distribution. Smart connectivity. Remote monitoring. Easy customization via digital modules. MasterPact MTZ circuit breakers bring the future-ready EcoStruxure Power capabilities you need to build smart, dependable, and sustainable power distribution systems:

  • Smartphone connectivity for wireless alerts and maintenance

  • Precision Class 1 power meter built in for energy-saving capabilities

  • Easy customization via digital modules

  • Intuitive MicroLogic™ X control unit

  • Robust performance, even in harsh environments

  • Seamless integration with building and energy management systems via EcoStruxure Power architecture

  • Designed and tested to applicable standards for ANSI, UL and IEC

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