Overview
The Eaton DG321NGB is a general duty safety switch designed for service entrance and light motor circuit applications. As a fusible, cartridge-fused disconnect, it combines manual switching control with overcurrent protection in a single NEMA 1 enclosure. This 3-pole, 4-wire switch operates at 240VAC with a 30-ampere rating, making it suitable for small commercial and residential installations requiring reliable load break and load make capability.
Key Features
- 100% load break and load make rated — Visible double-break rotary blade mechanism for safe, positive switching action
- Fusible design with cartridge fuses — Integrated overcurrent protection; supports Class H and Class R fuses
- NEMA 1 enclosure — General purpose, panel-mounted steel construction for protected indoor environments
- Neutral conductor included — 4-wire configuration for single- and three-phase applications
- Manual handle actuator — Intuitive, tactile operation with clear ON/OFF positioning
Technical Specifications
- Voltage Rating: 240VAC
- Current Rating: 30 amperes (continuous load not to exceed 80% of fuse rating in non-motor circuits)
- Poles: 3-pole, 4-wire (TPST contact form)
- Horsepower: 1.5–3 HP (single-phase); 3–7.5 HP (three-phase, grounded B phase)
- Fuse Type: Cartridge, Class H or Class R
- Enclosure Rating: NEMA 1
- Short Circuit Rating: 100,000 A RMS (with Class R fuses)
- Contact Form: TPST (Three-Pole Single Throw)
- Mounting: Surface/panel mount
- Dimensions: 6.38″ W × 10.69″ H × 6.88″ D
- Construction: Painted steel
- Approvals: UL Listed
Typical Applications
General duty safety switches like the DG321NGB are deployed in:
- Service entrance disconnects — Main load isolation for residential and small commercial panels
- Light motor circuits — Fractional and single-digit horsepower motor branch circuits
- Heating and cooling equipment — HVAC unit disconnect switches
- Lighting and receptacle loads — General branch circuit protection and isolation
- Backup equipment control — Generator and standby power circuits
Compatibility & Replacements
Compatible With
- Standard 240V single- and three-phase AC utility power systems
- Class H and Class R cartridge fuses (30A rating)
- NEMA 1 panel-mounted electrical enclosures
- Residential and light commercial branch circuit wiring (4 AWG to 10 AWG copper)
Replaces / Drop-In Replacement For
Verify compatibility with your electrical supplier or system integrator before ordering alternate or replacement models. The DG321NGB /B variant is the current production configuration.
Works With
- Cartridge fuse holders rated for Class H (pin-type) or Class R fuses
- Standard electrical service panels and sub-panels
- Motor starter and control circuit auxiliary contacts (when externally wired)
- Load calculation and branch circuit design per NEC® Article 430 (motor circuits) and Article 210 (branch circuits)
