Schneider 3CT-H1-100-C Current Transformer

Full Specification of Schneider 3CT-H1-100-C Current Transformer (Dedicated for EOCR)

Model Code Interpretation

Code Segment	Meaning	Description
3CT	Product Series	Three-phase combined current transformer, customized for Schneider EOCR motor protector, manufactured by SAMWHA Korea
H1	Specification Code	Primary current rating 100A, circular aperture, applicable for cable outer diameter ≤25mm
100	Rated Primary Current	100A (numerator of transformation ratio)
C	Mounting/Terminal Type	Terminal block type; Z stands for direct lead wire type

Quick Identification: 3CT-H1-100-C = Three-phase 100/5A circular-aperture current transformer with terminal block, exclusive for EOCR

Core Technical Parameters

Parameter Category	Specification	Remark
Transformation Ratio	100A/5A	Standard secondary current 5A, compatible with full EOCR series
Accuracy Class	Class 1	Measuring tolerance ±1%, meets protection and metering requirements
Rated Burden	10VA	Max permissible secondary loop impedance 200mΩ
Frequency Range	50/60Hz	General industrial frequency
Rated Insulation Voltage	AC 600V	Maximum continuous operating voltage
Withstand Voltage	2kV (50Hz, 1min)	Insulation test standard between windings and earth
Insulation Resistance	≥100MΩ (DC 500V)	Measured by megohmmeter
Aperture Size	Circular φ25mm	Standard bore of H1 series
Overall Dimension	W150×H71×D55mm	Compact structure, space-saving installation
Mounting Type	Panel mounting	Compatible with standard 35mm DIN rail
Material	Flame-retardant engineering plastic	Compliant with UL94 V0 standard
Weight	Approx. 0.58kg	Single unit weight
Certification	CE, UL	Conforms to international safety standards
Order Number	3CT-H1-100-C	Exclusive official Schneider order code

Full Model List (EOCR 3CT Series)

Model	Ratio	Aperture Shape	Bore Size	Rated Current	Mounting Type
3CT-HS-75-C/Z	75/5A	Circular	φ22mm	75A	C=Terminal block, Z=Lead wire
3CT-H1-100-C/Z	100/5A	Circular	φ25mm	100A	C=Terminal block, Z=Lead wire
3CT-HH-150-C/Z	150/5A	Square	30×30mm	150A	C=Terminal block, Z=Lead wire
3CT-H2-200-C/Z	200/5A	Square	35×35mm	200A	C=Terminal block, Z=Lead wire
3CT-H3-300-C/Z	300/5A	Square	45×45mm	300A	C=Terminal block, Z=Lead wire
3CT-H4-400-C/Z	400/5A	Square	55×55mm	400A	C=Terminal block, Z=Lead wire

Cross-brand Alternative Comparison

Brand	Model	Ratio	Accuracy	Burden	Aperture	Compatibility
Schneider (SAMWHA)	3CT-H1-100-C	100/5A	Class 1	10VA	φ25mm	Perfect match for EOCR
Siemens	5SD7410-7	100/5A	Class 1	10VA	φ25mm	Universal type, adaptation test required
ABB	CT-AR/100	100/5A	Class 1	15VA	φ25mm	Higher burden capacity, EOCR compatible
Chint	BH-0.66/100	100/5A	Class 1	10VA	φ25mm	Cost-effective domestic alternative
Delixi	LMZ1-0.66/100	100/5A	Class 1	10VA	φ25mm	Domestic replacement, minor dimension difference

Replacement Notes

Ensure secondary burden capacity ≥10VA for non-Schneider products to guarantee protection precision
Aperture shall match cable outer diameter; H1 series fits cables below 25mm
Calibrate transformation ratio and phase for alternative models
Troubleshooting & Maintenance

Fault Phenomenon	Possible Causes	Inspection Steps	Solutions
No secondary output	Wrong wiring, winding open circuit, loose terminals	Check S1/S2 polarity; test secondary resistance; fasten terminals	Correct wiring polarity; replace faulty CT; reinforce terminals
Large measuring deviation	Overloaded circuit, mismatched ratio, core saturation	Calculate loop impedance; verify ratio; check overload current	Reduce circuit burden; replace matched model; upgrade CT specification
EOCR false tripping	Phase shift, harmonic interference, CT saturation	Test three-phase phase difference; check frequency converter interference; monitor surge current	Recalibrate phase; install harmonic filter; adopt high-saturation CT
Insulation failure	Dampness, insulation aging, mechanical damage	Measure insulation resistance; inspect shell cracks; test winding insulation	Dry or replace unit; renew CT; repair damaged parts

Safety Rules

Never test open secondary circuit; short-circuit S1/S2 beforehand to avoid high voltage hazard
Check load and wiring preferentially when deviation exceeds ±2%
Replace CT immediately if insulation resistance below 10MΩ
Application & Cases

Applicable Scenarios

EOCR motor protection system: Overcurrent, undercurrent and phase loss protection

Low-voltage power distribution: Current monitoring and protection for circuits below AC 600V

Motor control center: Compact layout saves cabinet space

Industrial production lines: Heavy-duty equipment protection in steel, cement and automobile industry

UPS feeder in data center: Precise current monitoring

Inadmissible Scenarios

Long-term operating current over 120A causing core saturation

High frequency (>400Hz) or DC circuits with poor measuring accuracy

Outdoor installation without waterproof enclosure

Secondary circuit burden exceeding 10VA

Typical Cases

Case 1: Motor Protection in Automobile Workshop

3 sets of 55kW three-phase asynchronous motors equipped with EOCR-3E protector. Model 3CT-H1-100-C is selected. It realizes overcurrent trip and rapid phase loss protection, cutting down failure rate by 40%.

Case 2: Crane Control Cabinet Renovation

Replace old split CT with combined 3CT-H1-100-C, saving 50% installation space, simplifying wiring and improving operational reliability.

Selection & Installation Guidelines

Three-step Selection Method

Calculate current: Multiply rated motor current by 1.1 overload factor
Select aperture: Choose circular or square bore according to cable size
Confirm terminal type: Terminal block for cabinet wiring, lead wire for field wiring

Installation Precautions

Keep correct S1(I+) and S2(I-) connection to prevent false operation

Strictly prohibit open secondary circuit during installation and maintenance

Total secondary loop impedance shall not exceed 200mΩ

Insulation resistance shall be no less than 100MΩ before commissioning

Maintenance Schedule

Item	Cycle	Standard
Visual inspection	Monthly	No crack, looseness or overheating mark
Terminal tightening	Quarterly	Torque range 2-3N·m
Insulation test	Yearly	Resistance ≥100MΩ
Ratio calibration	Biennially	Tolerance ≤±1%

Schneider 3CT-H1-100-C is a dedicated three-phase 100/5A combined current transformer for EOCR motor protectors. Featuring Class 1 accuracy, 10VA rated burden and compact design, it is widely applied in low-voltage motor protection and power monitoring. Match current, aperture and terminal type properly, and comply with polarity and open-circuit prohibition rules to ensure stable system operation.