How to Identify Your MCC Bucket Model: Step-by-Step Guide

You need a replacement MCC bucket, but you are not sure exactly what you have. Maybe the nameplate is missing, the MCC is old, or you inherited a facility without documentation. This step-by-step guide walks you through identifying your MCC bucket accurately so you can order the right replacement.

Step 1: Find the MCC Nameplate

The most reliable identification method is the MCC main nameplate, usually located on the main incoming section (the section with the main breaker or main disconnect).

What to Look For

Manufacturer: Square D, Siemens, GE, Cutler-Hammer/Eaton, Westinghouse, Allen-Bradley, etc.
Model: Model 6, Tiastar, 8000, Freedom 2100, Type W, CENTERLINE 2100, etc.
Serial Number: Contains date code and manufacturing information
Bus Ratings: Horizontal and vertical bus amperage
Short-Circuit Rating: kA withstand rating
Voltage: System voltage rating

If the Nameplate is Missing or Illegible

Check other sections of the MCC. Some manufacturers put individual nameplates on each section. Also check inside the bucket compartments for supplementary identification labels.

Step 2: Identify the Manufacturer by Visual Clues

If you cannot find a nameplate, the physical characteristics of the MCC and buckets can identify the manufacturer.

Square D (Schneider Electric)

Door handle style is distinctive for each model (Model 4, 5, and 6 all differ)
Model 6: Quick-release door latch, modern styling
Model 5: Captive screw door latch, simpler styling
Model 4: Older latch design, heavier construction
Square D logo or "SD" marking may be visible on door handle or inside components

Siemens

Tiastar MCCs have a specific door handle design with the Siemens logo
Look for Siemens-branded components inside (3RT contactors, 3RB overloads, 3VA breakers)
Door latch mechanism is distinct from other brands

GE (ABB)

GE 8000 series has a recognizable door handle design
Look for GE-branded breakers (TEB, TED, TEF series)
GE logo may be embossed on door handles or structural members

Cutler-Hammer (Eaton)

Freedom series has a distinctive door handle with Eaton or Cutler-Hammer logo
Look for Eaton/Cutler-Hammer branded components
Door latch style is unique to the Freedom platform

Allen-Bradley (Rockwell)

CENTERLINE 2100 has the Allen-Bradley/Rockwell logo on door handles
Look for AB-branded contactors (Bulletin 500/509) and overloads (E300)
Often has network communication modules visible

Westinghouse

Older MCC with Westinghouse branding on nameplate or components
Type W designation
Distinctive older-style door handles and latches

Step 3: Examine the Stab Assembly

If you can safely remove a bucket (de-energized, LOTO), the stab assembly on the back of the bucket is one of the most definitive identification features.

What to Document

Number of stabs (three-phase will have 3 power stabs)
Stab finger design (spring-loaded, clip, bolt-on)
Stab mounting pattern on the bucket back panel
Physical dimensions of the stab assembly
Any markings or part numbers on the stab assembly

Each manufacturer uses a proprietary stab design. Even within a manufacturer's product line, different models often have different stab configurations (e.g., Square D Model 5 vs. Model 6).

Step 4: Measure the Bucket

Physical dimensions help confirm the bucket model and determine sizing for replacement:

Key Measurements

Height: Measure the door opening height (6", 12", 18", 24", 36", or 48")
Width: Should be approximately 20 inches for standard MCCs
Depth: Measure from the front of the bucket to the back of the stabs
Door opening size: The actual usable opening may differ from the bucket height

Bucket Type

Feeder: Contains only a disconnect device (breaker or fused switch)
Starter: Contains a disconnect plus contactor, overload relay, and control devices
VFD: Contains a variable frequency drive

Step 5: Document Internal Components

Open the bucket door and photograph/record all internal components:

For Starter Buckets

Disconnect type and amperage (breaker model number or fuse size)
Contactor manufacturer and size (NEMA size or model number)
Overload relay type (thermal or electronic, model number)
Control transformer VA rating and voltage
Control devices (pushbuttons, selector switches, lights)

For Feeder Buckets

Disconnect type and amperage
Any additional components (meters, indicating lights)

For VFD Buckets

VFD manufacturer, model, and HP rating
Input and output reactor details
Bypass contactor (if present)

Step 6: Take Photos

Photos are the single most valuable tool for identification. Take the following:

MCC nameplate: Close-up, in focus, readable
Full MCC front view: Shows the overall MCC lineup
Bucket door (closed): Shows door handle style and controls
Bucket door (open): Shows interior component layout
Bucket nameplate: Any labels on the bucket itself
Stab assembly: Back of the bucket showing stab connections
Vertical bus: View inside the MCC section showing where stabs engage
Component nameplates: Breaker, contactor, overload relay model numbers

Step 7: Use MCC Depot's Identification Service

If you have gone through these steps and still cannot identify your MCC bucket, MCC Depot can help. Our team has seen virtually every MCC configuration in production over the past 50 years.

Visit our bucket identification page and submit your photos. We will identify your MCC and bucket model and provide a quote for replacement.

What to Send Us

All photos from Step 6
Any nameplate data you can read
Facility age (when was the building built?)
Geographic location (some MCC brands were more common in certain regions)
Motor HP and voltage (for starter buckets)

Call 307-442-0382 or email sales@mccdepot.com with your photos and information.