Description
The Square D EH34040 is a three-pole molded case circuit breaker designed to provide reliable overcurrent and short-circuit protection in commercial electrical distribution systems. Rated at 40 amps and 480Y/277 VAC, this breaker uses thermal-magnetic trip technology to deliver long-time and instantaneous protection. It is engineered for plug-in installation in compatible Square D NEH panelboards.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Square D |
| Category |
Circuit Protection |
| Part Number |
EH34040 |
| Subcategory |
Circuit Breakers |
| Series |
EH |
| Product Type |
Molded Case Circuit Breaker |
| Frame Type |
EH |
| Rated Current |
40 A |
| Number of Poles |
3 |
| Phase |
Three Phase |
| Voltage Rating |
480Y/277 VAC |
| Protection Type |
Thermal-Magnetic |
| Interrupting Rating |
14 kAIC @ 277 V |
| Connection Type |
Plug-In |
| Wire Size |
AWG 14–2 Aluminum/Copper |
| Functions |
Long-Time and Instantaneous (LI) |
| Ambient Temperature Rating |
40 °C |
| Application |
Power Distribution |
| Weight |
3.0 lb (approx.) |
Information About EH34040
The EH34040 is part of Square D’s EH series of molded case circuit breakers, developed for compact branch circuit protection in low-voltage panelboard applications. This breaker incorporates a thermal-magnetic trip unit that protects circuits from overloads and short-circuit faults while maintaining stable operation. It is designed for three-phase electrical systems and supports both copper and aluminum conductors within a defined wire range. Built to meet UL and CSA requirements, the breaker is intended for dependable operation in controlled commercial and light industrial environments.
Key Features:
- 40 Amp Current Rating: Provides accurate protection for three-phase branch circuits.
- Three-Pole Configuration: Ensures balanced protection across all phases.
- 480Y/277 VAC Rating: Suitable for common commercial power distribution systems.
- Thermal-Magnetic Protection: Combines long-time overload and instantaneous trip functions.
- Plug-In Mounting Design: Enables secure installation in compatible NEH panelboards.
- 14 kA Interrupting Rating: Rated for fault protection at 277 VAC.
- Copper and Aluminum Compatibility: Accepts conductors from AWG 14 to AWG 2.
The EH34040 delivers the reliability and precision required for commercial three-phase power distribution protection.
