Schneider Samwha EOCR 3CT-H2-200-C Three-Phase Integrated Current Transformer

Samwha EOCR from Korea, integrated into the Schneider EOCR product line, made in Korea, exclusively for EOCR motor protection relays.

Model Definition

3CT: Three-phase integrated current transformer with three through-hole cores

H2: Size code, corresponding to the cable window for 200A model

200: Primary rated current: 200 A

C: Old version suffix; Z is the new replacement model (3CT-H2-200-Z). Electrical parameters are identical, only version revision, direct plug-and-play replacement.

Core Electrical Specifications

Transformation ratio: 200/5 A

Accuracy class: Class 3.0

Rated burden: 1.25 VA (Version C) / 5 VA (New Version Z)

Frequency: 50/60 Hz

Withstand voltage: 1150 V

Short-time thermal stability: 40Ith / 1 second

Insulation resistance: ≥10 MΩ @ 500 V DC

Applicable circuit: AC 600 V motor circuit

Weight: approx. 580 g

Overall Dimensions

W150 mm × H55 mm × D71 mm

Integral epoxy encapsulation, three circular cable holes; DIN rail / panel mounting

Secondary terminals: K1, K2 (three independent windings for each phase); secondary wire: 1.5~4 mm² flexible cable

Application & Matching

✅ Designed exclusively for: EOCR-3DE, FDE, SSD, 3MZ and other digital motor protection relays. It samples three-phase current to implement overload, phase loss, locked rotor and current unbalance protection.

✅ Application scenarios: Three-phase asynchronous motor control cabinets, fans, water pumps, compressors and conveyor power circuits.

❌ Not suitable for energy metering (Class 3 accuracy for protection only, not for measurement).

Model Selection & Replacement

New in-stock replacement: 3CT-H2-200-Z, direct replacement for 3CT-H2-200-C

Other models in the same series:

3CT-H1-100-Z: 100/5 A

3CT-HH-150-Z: 150/5 A

3CT-H3-300-Z: 300/5 A

3CT-H4-400-Z: 400/5 A

Installation Guidelines
Run the main power cable directly through the three holes; P1 = supply side, P2 = motor side. Polarity reversal will cause phase error and false phase-loss tripping. CT secondary circuit must never be open-circuited.
Use only identical 3CT models with one relay; do not mix CTs with different transformation ratios.
Ambient temperature: -20 ~ +60 ℃; Max altitude: 2000 m.
Wiring Instruction for 3CT-H2-200-C (New Model: 3CT-H2-200-Z)

Three-phase integrated CT with independent secondary windings for R/S/T phases, secondary output 5 A. Only compatible with EOCR motor protectors; cannot be connected to ordinary ammeters or metering devices.

Terminal Definition

Primary side: Three holes for L1(R), L2(S), L3(T) power cables

Polarity rule: P1 (power supply) → P2 (motor load); arrow points toward the load. Reversed polarity leads to phase fault and incorrect phase-loss alarm.

Secondary terminals (3 groups from top to bottom):

R phase: K1, K2

S phase: K1, K2

T phase: K1, K2

Secondary cable: 1.5~4 mm² flexible wire; shielded twisted pair is recommended; cable length ≤ 15 m.

Standard Wiring (EOCR-3DE / FDE / 3MZ / iFMZ / i3MZ)

R-phase K1 → EOCR I1; R-phase K2 → common COM terminal
S-phase K1 → EOCR I2; S-phase K2 → common COM terminal
T-phase K1 → EOCR I3; T-phase K2 → common COM terminal

✅ All three K2 terminals are tied together to the protector’s current COM; single-point grounding at the COM terminal is recommended.

❌ Never allow secondary open circuit (will cause accuracy drift and insulation breakdown).

Note on mechanical life: The term “mechanical life” only applies to devices with moving contacts and mechanical structures (contactors, circuit breakers, relays). Current transformers (CT) and voltage transformers (PT) are static components without moving parts. Their service indicators are insulation life, thermal stability and environmental durability only.

Maintenance & Replacement Cycle (On-site O&M Reference)

Normal environment (fan & pump, clean indoor cabinet): Evaluate replacement after 8~12 years

Harsh environment (high temperature, dust, VFD circuits, frequent direct-on-line motor starting): Check insulation and transformation ratio every 5~7 years

After short-circuit heavy current impact: Test or replace immediately. The iron core will suffer hidden performance degradation, resulting in current sampling deviation and false tripping of the protector.

Supplementary Note

New model 3CT-H2-200-Z shares the same mechanical structure, iron core and encapsulation as version C, with identical durability. Only the rated burden is upgraded from 1.25 VA to 5 VA, making it more stable for long secondary cables and VFD applications. Mounting holes are fully interchangeable with no cabinet modification required.

Naming Rule for 3CT-H Series Three-Phase Integrated CT

Format: 3CT-XX-XXX-Suffix

3CT: Three-phase combined current transformer (EOCR dedicated)

H1/HH/H2/H3/H4: Size code (cable window dimension)

Numeral: Primary current (secondary output 5 A)

Suffix: C = Old version (discontinued); Z = New version (active replacement)

Accuracy: Class 3.0; Secondary output: 5 A; Compatible with all EOCR motor protectors.

Full Model List (Old C-version + New Z-version, one-to-one match)

Full Specifications (ascending current rating)

3CT-HS-75, Ratio: 75/5 A

Old: 3CT-HS-75-C (discontinued)

New: 3CT-HS-75-Z (in production)

3CT-H1-100, Ratio: 100/5 A

Old: 3CT-H1-100-C (discontinued)

New: 3CT-H1-100-Z (in production)

3CT-HH-150, Ratio: 150/5 A

Old: 3CT-HH-150-C (discontinued)

New: 3CT-HH-150-Z (in production)

3CT-H2-200 (Your model), Ratio: 200/5 A

Old: 3CT-H2-200-C (discontinued)

New: 3CT-H2-200-Z (direct interchange)

3CT-H3-300, Ratio: 300/5 A

Old: 3CT-H3-300-C (discontinued)

New: 3CT-H3-300-Z (in production)

3CT-H4-400, Ratio: 400/5 A

Old: 3CT-H4-400-C (discontinued)

New: 3CT-H4-400-Z (in production)

Key Differences between C-version & Z-version

Old suffix -C: Rated burden 1.25 VA, limited short secondary wiring length

New suffix -Z: Rated burden upgraded to 5 VA, better stability for long cables and VFD circuits; mounting footprint fully compatible for drop-in replacement without cabinet changes.