Eaton K Series OPTIM Circuit Breaker Installation Guide

Eaton K-Series Digitrip OPTIM Circuit Breakers: A Comprehensive Guide to Installation, Configuration, and Testing

Product Overview and Technical Specifications

1.1 Applicable models and rated values

The K series OPTIM circuit breakers include the following models:

KD/HKD/KDC: Standard and high breaking types, suitable for 600 Vac systems

CKD/CHKD: 100% rated continuous current type, suitable for high load continuous operation scenarios

Rated current range: 125A, 250A, 400A (adjusted through rated plug)

1.2 Compliance with standards

UL 489: Aged Case Circuit Breaker Standard

IEC 157-1: International Standard for Low Voltage Circuit Breakers

NEC Article 230-95: Requirements for Installation and Testing of Grounding Fault Protection System

1.3 100% rated application instructions

CKD and CHKD models can achieve 100% continuous rated operation under the following conditions:

Use insulated wires at 90 ° C

Cooperate with AL9CU terminal

Installed in a standard cabinet with a minimum size of 24 "high x 15" wide x 6 "deep (no ventilation required)

Preparation and safety warning before installation

⚠️  Important safety tips

Before installing or maintaining equipment, it is necessary to confirm that the equipment has been powered off and comply with local safety regulations. Eaton shall not be liable for any losses caused by misuse or incorrect installation.

2.1 Open box inspection

Check if the nameplate data matches the system requirements

Check for any physical damage during transportation

Confirm that the accessory package (terminals, rated plugs, installation screws, etc.) is complete

Mechanical installation steps

3.1 Disassembling the casing

Ensure that the circuit breaker is in the "trip" or "OFF" position

Remove the cover screws and take off the front cover

3.2 Installation of rated plugs and internal accessories

The rated plug must be matched with the trip unit (see Table 2-2)

It is recommended to install internal accessories such as auxiliary switches and alarm switches before installation

3.3 Installing Terminals

Select aluminum or copper terminals based on wire type (see Table 2-1)

Use a 7/32 inch socket wrench with a torque setting of 6-8 lb ft (8-11 N · m)

3.4 Installing the Circuit Breaker Body

Drill holes in the bottom plate according to the drilling diagram in Figure 2-2

Secure with M4 or M5 screws, with a torque not exceeding 28 lb in (3 N · m)

Definition of Electrical Wiring and Control Terminals

4.1 Main circuit wiring

The wiring between cables and load terminals must be carried out according to the terminal torque table

If aluminum wires are used, it is recommended to use specialized joint compounds to prevent overheating

4.2 Definition of Control Terminals (Figure 2-5)

The OPTIM trip unit supports multiple functional interfaces, and the terminal definitions are as follows (partially):

Terminal number, signal name, function description

1 GF Alarm Ground Fault Alarm

2 Zone OUT interlocking output

3 Zone IN interlocking input

Positive pole of 6+24 Vdc control power supply

7/8 NS/NS * neutral point sensor input

15-19 Bell/Aux alarm and auxiliary switch

⚠️  Attention: The polarity of the+24 Vdc power supply must not be reversed, otherwise it may damage the electronic protection function.

Release unit configuration and communication settings

5.1 Selection of rated plugs

The rated value of the trip unit can be achieved using the rated plug

125A 63A, 70A, 90A, 100A, 110A, 125A

250A 125A, 150A, 160A, 175A, 200A, 225A, 250A

400A 200A, 225A, 250A, 300A, 350A, 400A

5.2 Parameter Setting Method

Using the handheld programmer Digittrip OPTIMZER

Or remotely set up with IMPACC software through INCOM communication module

Manual operation and reset

6.1 Position indication of handle

Red: ON

White: TRIP

Green: OFF

6.2 Reset Operation

Push the handle to the "Reset" position (OFF limit) to reset it

The reset button is only used to clear the LED fault indication and does not affect the mechanical reset

6.3 PUSH-TO-TRIP Function

Press the test button on the trip unit with a small screwdriver to simulate a faulty trip

Suggest regular operations to verify the flexibility of the institution

On site inspection and maintenance

7.1 Regular inspection items

Clean surface dust (using a lint free cloth or vacuum cleaner)

Manually switch on and off several times, check if the mechanism is flexible

Check the terminals for signs of discoloration, melting, or corrosion

Check the shell for cracks or discoloration

7.2 Grounding Fault System Performance Test (NEC 230-95 (C) Requirement)

All grounding fault protection systems must undergo performance testing during their initial installation, and test records must be filled out (Figure 4-1).

Test 1: Single phase power on test (should trip)

Apply a current of 125% of the ground fault setting value in one phase

The circuit breaker should trip within 1 second and the alarm indicator should activate

Test 2: Neutral point return test for four wire system (should not trip)

Current passes through one phase and returns through the neutral point sensor

The circuit breaker should not trip, and the alarm should not activate

Test 3: Two way electrical test for three wire system (should not trip)

Current passes through any two phases

The circuit breaker should not trip, and the alarm should not activate

⚠️  Attention: After all tests are completed, the original wiring state must be restored.