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Phone: +86 16626708626Description
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | EATON / Cutler-Hammer |
| Model Number | C306DN3 |
| Product Type | Thermal Overload Relay |
| Application | Motor starter and industrial motor protection circuits |
| Protection Type | Thermal overload protection |
| Phase Compatibility | Three-phase motor applications |
| Mounting Type | Contactor-mounted overload unit |
| Series | C306 Motor Control Series |
| Reset Function | Manual/automatic reset configuration depending on installed option |
| Control Voltage Compatibility | Determined by associated contactor and control circuit |
| Operating Environment | Industrial control panel environments |
| Replacement Category | Legacy motor control spare part |
Product Introduction & Supply Chain Strategy
The EATON C306DN3 is a thermal overload relay designed for motor starter assemblies and industrial motor protection applications. It monitors motor current conditions and trips the control circuit when sustained overload conditions exceed the configured protection range.
Maintaining New Surplus C306DN3 inventory supports plants operating legacy EATON Cutler-Hammer motor control systems. Strategic stocking reduces downtime risk caused by discontinued components, unstable lead times, and unverified replacement sources while improving Total Cost of Ownership (TCO).
Installation & Configuration Guide
Stage 1: Pre-Installation (Prep & Safety)
- Apply lock-out/tag-out (LOTO) procedures before opening the motor control enclosure.
- Verify the existing overload relay model and electrical ratings match the replacement unit.
- Wear an ESD wrist strap when handling the component.
- Photograph:
- Existing wiring connections
- Contactor arrangement
- Reset configuration
- Terminal markings
Required tools:
- Insulated screwdriver set
- Multimeter
- Torque screwdriver
- ESD protection equipment
Stage 2: Removal
- Confirm all incoming power sources are isolated.
- Verify zero voltage at the starter terminals.
- Disconnect control and power wiring carefully.
- Release the overload relay mounting mechanism.
- Remove the existing relay without forcing the contactor connection points.
Avoid bending terminals or damaging contactor mounting surfaces.
Stage 3: Installation (Clone & Seat)
- Compare the replacement C306DN3 with the removed unit.
- Confirm terminal positions and mechanical fit.
- Install the overload relay onto the compatible contactor assembly.
- Reconnect wiring according to the original photos and plant drawings.
- Verify all terminal screws meet manufacturer torque requirements.
- Confirm overload adjustment settings match the original configuration.
Stage 4: Power-On & Testing
- Check control circuit wiring for shorts before energizing.
- Verify motor starter control voltage.
- Energize the circuit.
- Observe relay indicators and contactor operation.
- Confirm:
- Motor starts correctly
- Overload trip function operates correctly
- Auxiliary contacts change state correctly
Record final settings in the maintenance documentation system.
C306DN3
C306DN3
Firmware/Software Versions & Upgrade Notes
- Firmware: Not applicable. The EATON C306DN3 is an electromechanical thermal overload relay.
- Configuration Dependency: Protection settings are hardware-adjusted through overload current settings.
- Compatibility Notes: Confirm compatibility with the installed EATON/Cutler-Hammer contactor frame before replacement.
- Upgrade Warning: Do not substitute electronic overload modules without reviewing motor protection requirements, coordination settings, and control system documentation.
- Replacement Risk: Incorrect overload class or current adjustment may cause nuisance trips or insufficient motor protection.
Frequently Asked Questions (FAQ)
Q1: Is the EATON C306DN3 a new product or refurbished unit?
The available units supplied through strategic industrial inventory channels are New Original / New Surplus components. They are not refurbished or repaired units.
Q2: Why is New Surplus pricing different from standard OEM pricing?
New Surplus inventory typically comes from previously manufactured OEM stock. It provides access to genuine components while avoiding the higher cost structure of current catalog replacements.
Q3: Is the obsolete or still commonly produced?
The C306 series is considered a legacy motor control product family. Plants still operating compatible equipment should maintain Buffer stock or establish a Last-time-buy strategy.
Q4: Can I directly replace my existing overload relay with the ?
Verify the contactor model, motor full-load current, overload adjustment range, and mounting configuration before installation.
Q5: Does replacing the overload relay require PLC programming?
No. The is an electromechanical protection device and does not require firmware or PLC programming changes.
Q6: What should I keep as spare inventory?
For critical motor applications, maintaining 1–2 units on-site is recommended as insurance against unexpected failures and supplier lead time variability.
Q7: What quality documentation is available?
New Original / New Surplus supply should include traceability information such as product labeling, serial information where applicable, and inspection records.
