Description

GCT-Y Circular Residual Current Transformer

The GCT-Y circular residual current transformer is a compact through-core sensor for cable circuits. Y-25 to Y-200 models provide 25 mm to 200 mm through-core apertures for primary circuit currents from 63 A to 2,000 A. The series supports 50-400 Hz operation, multiple accuracy classes, and full-scale output options for residual-current monitoring and protection systems.

Residual-Current Measurement

The cable passes through the transformer core so the device can sense residual or unbalanced current and provide a proportional measurement signal to a compatible monitoring or protection device. GCT-Y provides the sensing signal; alarm or trip logic is handled by the connected monitoring or protection device. The series is designed around balance characteristics that can support unbalanced-current output better than 30 mA, 10 mA, 5 mA, or 3 mA, helping limit false alarms caused by interference from the main-circuit current magnetic field.

Key Features

Through-core construction: Compact structure for cable-circuit installation with flexible aperture selection.
Magnetic materials: High-permeability nickel steel or nanocrystalline core options provide good linearity and sensitivity.
Encapsulation: Flame-retardant epoxy resin casting supports stable internal construction.
Interference resistance: Balance characteristics and electromagnetic-interference resistance support reliable residual-current signals.

Typical Applications

Use the GCT-Y series in electrical fire monitoring, fire-prevention and leakage systems, intelligent power systems, small-current grounding systems, electromagnetic relay protection, microcomputer protection, intelligent power equipment, and environmental protection monitoring.

Selection and Installation Notes

Select the through-core aperture to match the cable arrangement and the required primary circuit current.
Match the nominal residual-current input, full-scale output, accuracy class, and overall residual-current measurement range to the connected monitoring or protection device.
The Y-25 to Y-200 models use screw fixation. Connection options are listed as terminal type or 1.5 m shielded twisted wire.
Confirm the installation environment is within -12°C to +45°C and ambient humidity does not exceed 85%.
Please contact GEYA for the complete ordering matrix and wiring details for the selected aperture, input, output, and accuracy configuration.

Referenced Standard Requirements

The product information references GB 14287.2-2005 and GB 14287.2-2014 requirements. Please contact GEYA for current compliance documents for the selected configuration.

Technical Parameters

Electrical parameter	Specification
Product model	GCT-Y
Product type	Circular residual current transformer, through-core type
Through-core aperture	25-200 mm
Primary circuit current	63-2,000 A
Working frequency	50-400 Hz
Nominal residual-current input (In)	In = 1 A (0-1 A input span)
Overall residual-current measurement range	10 mA-5 A total sensor response range
Accuracy-assured residual-current range	10% In-130% In (0.1-1.3 A when In = 1 A)
Full-scale output options (at In)	0-1 V or 0-0.5 mA
Ratio difference	Within ±0.1%
Phase difference	Within ±10 arcmin
Dielectric strength	2.5 kV / 1 mA / 1 min
Insulation resistance	DC 500 V / 1,000 MΩ / 1 min
Referenced standards	GB 14287.2-2005; GB 14287.2-2014

Input terminology: All input figures in this section refer to residual current, not primary circuit current. Nominal residual-current input (In) is 1 A; the associated 0-1 A input span is used for full-scale output and monitoring-host matching. The overall residual-current measurement range is the complete sensor response range from 10 mA to 5 A. The accuracy-assured residual-current range is 10% In to 130% In, which corresponds to 0.1-1.3 A when In = 1 A. Currents above 1.3 A may still be detected up to 5 A, but accuracy is not guaranteed.

Please contact GEYA to match the required input and output interface to the selected aperture and accuracy class.

Mechanical and Environmental Parameters

Mechanical parameter	Specification
Shell	ABS, flame-retardant grade 94-V0
Skeleton	PBT
Iron core	Nickel steel or nanocrystalline
Internal structure	Environment-friendly epoxy resin casting
Construction plan	Screw fixation
Working temperature	-12°C to +45°C
Ambient humidity	≤85%
Connection mode	Terminal type or 1.5 m shielded twisted wire

Y-Model Outline and Installation Dimensions

Model	Nominal residual-current input (In)	Full-scale output	Accuracy class	Aperture (Φ)	A (mm)	B (mm)	C (mm)	D (mm)	G
Y-25	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	25 mm	56	60	21	48.5	M5
Y-45	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	45 mm	79.5	83.5	24	66.5	M5
Y-65	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	65 mm	99.5	104	24	86.5	M5
Y-80	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	80 mm	113.5	119	26	101.5	M5
Y-100	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	100 mm	135.5	141	26	114.5	M6
Y-150	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	150 mm	189.5	196	27	171	M6
Y-200	In = 1 A (0-1 A input span)	0-1 V (0.5 mA)	0.1 / 0.2 / 0.5 / 1.0	200 mm	239.5	246	30	221	M8

FAQs

What is the GCT-Y circular residual current transformer?

GCT-Y is a compact through-core transformer for sensing residual or unbalanced current in cable circuits and sending a proportional signal to a compatible monitoring or protection device.

Which through-core apertures and primary currents are available?

The Y-25 to Y-200 model range covers 25 mm, 45 mm, 65 mm, 80 mm, 100 mm, 150 mm, and 200 mm apertures. The series overview covers primary circuit currents from 63 A to 2,000 A.

Why are both 0-1 A and 10 mA-5 A shown in the specifications?

They describe different parts of the input specification, and both refer to residual current rather than the primary circuit current. The model matrix uses nominal residual-current input (In = 1 A) and shows its associated 0-1 A input span for monitoring-host matching and full-scale output. The electrical table uses overall residual-current measurement range for the complete sensor response range from 10 mA to 5 A. The accuracy-assured range is 10% In to 130% In, or 0.1-1.3 A when In = 1 A; currents above 1.3 A may still be detected up to 5 A, but accuracy is not guaranteed.

Which accuracy classes can be selected?

The Y-model matrix lists accuracy classes 0.1, 0.2, 0.5, and 1.0. Select the class that matches the monitoring or protection device and contact GEYA for the complete configuration matrix.

How does GCT-Y help reduce false alarms?

Its balance characteristics and electromagnetic-interference resistance are intended to limit measurement disturbance from the main-circuit current magnetic field. The listed unbalanced-current output levels can be better than 30 mA, 10 mA, 5 mA, or 3 mA.

Where is the GCT-Y series used?

Typical applications include electrical fire monitoring, fire-prevention and leakage systems, intelligent power systems, small-current grounding, electromagnetic relay protection, microcomputer protection, and environmental monitoring.

What materials and environmental conditions should be checked?

The listed construction uses an ABS shell, PBT skeleton, nickel steel or nanocrystalline core, and epoxy resin casting. The working temperature is -12°C to +45°C, with ambient humidity up to 85%.

Which standards are referenced for the GCT-Y series?

The product information references GB 14287.2-2005 and GB 14287.2-2014. Please contact GEYA for current compliance documents for the selected configuration.

GCT-Y Residual Current Transformer