Eaton C825KN10 Cutler-Hammer 200 A NEMA Size 4 Contactor

Description

Product Introduction & Engineering Value

Nothing derails a shift like a Size 4 contactor that welds shut on a compressor or large fan starter. The C825KN10 was built for exactly that duty: high inrush, frequent starts, and the kind of mechanical abuse found in older motor-control centers.

This Cutler-Hammer Freedom contactor combines a 200 A, three-pole contact set with a 120 VAC coil and one normally open auxiliary contact. It is a direct legacy replacement consideration for existing NEMA Size 4 FVNR starters, particularly where the original panel layout, wire bending radius, and control scheme must remain unchanged.

Technical Specifications

The 200 A, 600 VAC, 3-pole, 120 VAC-coil configuration is consistently identified across supplier and equipment listings.

Field Application & The “Trench” Experience

A water-treatment contractor had a 75 HP raw-water pump starter that tripped intermittently after years of service. The original Cutler-Hammer contactor showed pitted poles and a weak auxiliary contact, but the MCC layout left almost no room for a modern retrofit. A verified C825KN10 allowed the crew to retain the existing Size 4 mounting pattern, control wiring, and overload-relay arrangement—getting the pump back in service during a scheduled outage rather than committing to a panel redesign.

Specific applications where this contactor fits well:

• Municipal raw-water and booster pump FVNR starters
• Large HVAC chiller, condenser-fan, and compressor motor switching
• Crusher, conveyor, and heavy fan starters in mineral-processing plants
• Legacy MCC replacements where a NEMA Size 4 footprint must be preserved

C825KN10

C825KN10

Transparency SOP: QA & Testing

• Nameplate and revision check: Confirm C825KN10, Series A2, coil voltage, pole configuration, and current rating before release.
• Coil verification: Measure coil resistance and perform a controlled 120 VAC pull-in and drop-out test.
• Contact inspection: Check pole alignment, contact wear, pitting, pressure, and evidence of overheating or welding.
• Mechanical operation: Cycle the contactor and verify free movement, positive auxiliary-contact action, and absence of binding.
• Insulation checks: Perform insulation-resistance testing between poles and between power circuit and coil/ground where appropriate.
• Final documentation: Record test results, condition grade, and any replaced components for traceability.

The Veteran’s Tech Trap Guide

⚠️ Verify the coil before ordering. The C825KN10 is commonly configured with a 120 VAC, 60 Hz coil, but control circuits may be 110 VAC 50 Hz, 208/240 VAC, or 480 VAC. The wrong coil will either chatter or burn out quickly.

⚠️ Do not assume the auxiliary contact count. The standard unit includes one NO auxiliary contact. If your seal-in circuit, PLC input, or interlock requires an NC contact or additional contacts, confirm the auxiliary block configuration separately.

PRO TIP: Inspect the load-side cable lugs and contact pressure after installation. On Size 4 starters, loose terminations and repeated high-inrush starts often cause more downtime than the contactor itself.

⚠️ Confirm FVNR versus reversing duty. This is a non-reversing contactor. A reversing starter requires mechanically and electrically interlocked forward/reverse contactors—not a single C825KN10.

Dynamic FAQ

Is the C825KN10 a circuit breaker?
No. It is a NEMA Size 4 AC magnetic contactor for switching motor and power loads; it does not provide the overcurrent protection function of an MCCB.

What coil voltage does C825KN10 use?
The standard configuration is a 120 VAC, 60 Hz coil, Eaton part 9-1891-1. Confirm the control-circuit voltage before substitution.

What motor size can it handle?
It is rated for 100 HP at 480/600 VAC in full-voltage, non-reversing service.

Does it include auxiliary contacts?
It includes one normally open auxiliary contact. Additional NO/NC auxiliary blocks may be required for seal-in, interlocking, or PLC feedback circuits.

Is this part discontinued?
The C825KN10 is a legacy Cutler-Hammer Freedom-series component and is commonly sourced as New Surplus or refurbished stock; verify the Series A2 designation and coil configuration before ordering.

What warranty applies?
New Surplus and refurbished units include a defined replacement warranty; the exact term and condition grade are identified on the quotation and shipment documentation.