GE TKM3F K1200 TKM MCCB Unit

Module Feature

TKM3F is a large-frame molded case circuit breaker frame from GE K1200 TKM series. It is a 3-pole bolt-on type base frame without built-in trip unit, compatible with a variety of GE thermal magnetic or electronic trip modules for flexible protection configuration. Frame rated 1200A, rated voltage 600VAC, interrupting capacity Icu 30kA at 480V. Auxiliary contact, alarm switch and shunt trip accessories are field installable. Widely stocked as spare for factory main switchboards, mining and heavy industry low voltage distribution cabinets.

Working principle

After matching with corresponding trip unit, current sensing elements monitor three-phase load current continuously. Thermal magnetic trip provides overload inverse time delay and instantaneous short-circuit protection; electronic trip versions support adjustable LSI/LSIG curves. Once fault condition is detected, the contact mechanism trips rapidly and isolates the fault circuit. Auxiliary contacts feed back breaker ON/OFF and trip status signals.

Onboard components

Main contact assembly, arc quenching chamber, spring operating mechanism, bolt-on terminal lugs, operation handle, insulated housing, trip unit mounting cavity.

LED indicators

Front mechanical markers display ON, OFF and trip status.

Hardware self‑diagnosis

Depends on fitted trip unit. Thermal magnetic trip version is passive without electronic self-check; electronic trip unit supports CT supervision and fault logging.

Programming software

Not applicable for bare frame; GE breaker configuration software is used if electronic trip unit is installed.

Electrical & Process Parameters

Model: TKM3F Brand: General Electric Device type: Molded case circuit breaker frame Frame rating: 1200 A Pole: 3P Rated voltage: 600 VAC Icu: 30 kA @480VAC Mount: Bolt-on Function: Overload and short-circuit protection for heavy low voltage distribution feeders

Mechanical & Structure

Mounting: Panel bolt-on mounting inside LV switchgear Protection class: IP40 front panel Housing: Reinforced insulated plastic enclosure

Environmental

Operating temperature: -25℃ ~ +60℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non‑condensing

Certification: UL489, CE Status: Original GE electrical distribution spare

Installation

Cut off upstream power supply before replacement. Install trip unit into frame cavity first, mount breaker on busbar support, tighten terminal lug bolts, wire auxiliary or trip accessories if fitted, set trip parameters, test close, open and trip function after commissioning.

Interface

Three-phase main bolt terminals, trip unit interface, auxiliary / alarm contact terminals, shunt trip terminals.

Diagnostic

Overload trip: Load current exceeds trip unit long delay setting. Instant short trip: Severe short circuit on downstream circuit. Failed closing: Trip latch locked or mechanism damaged.

Product Brief

TKM3F breaker frame, GE K1200 TKM 3P 1200A bolt-on MCCB frame spare for heavy industrial low voltage feeder protection replacement.