CT102 CT103 High Accuracy Current Transformer For Industrial Energy Meter
This mini current transformer is a precision current sensing component designed for
AC current measurement, metering and protection in compact electronic equipment.
It uses a high-permeability ferrite / nanocrystalline toroidal core fully sealed in a
flame-retardant plastic housing, converting a large primary AC current into a small,
proportional and easily processed secondary signal. The through-hole (window) design
allows the primary conductor or busbar to simply pass through the aperture, so no
primary winding connection is required and installation is fast and non-invasive.
Two termination versions are available: a straight-pin version for direct PCB
soldering and a flying-lead version with a twisted red/black cable and a plug-in
connector for panel or harness assembly. The D-shaped low-profile body saves board
space in energy meters, power strips, chargers and control boards, while the epoxy
potting protects the winding against vibration, humidity and dust.
Built by a manufacturer with 26 years of magnetic component experience, this current
transformer is produced under an ISO 9001 quality system and supports full
customization of turns ratio, aperture size, lead length, connector type and housing
dimensions to match your circuit design.
| No. | Item | Specification |
|---|---|---|
| 1 | Product type | Through-hole (window type) AC current transformer |
| 2 | Core material | High-permeability ferrite / nanocrystalline, customizable |
| 3 | Rated input current | 5 A / 10 A / 20 A / 50 A / 100 A (other values customizable) |
| 4 | Rated output current | 2 mA / 5 mA (matched to selected turns ratio) |
| 5 | Turns ratio | 1000:1 / 2000:1 / 2500:1 / 5000:1, customizable |
| 6 | Accuracy class | 0.1 / 0.2 / 0.5 (selectable by application) |
| 7 | Phase angle error | Typ. <= 30' at rated current |
| 8 | Linearity range | 0 - 120% of rated primary current |
| 9 | Recommended sampling resistor | 10 - 200 ohm, depending on output signal required |
| 10 | Operating frequency | 50 Hz / 60 Hz (extended range on request) |
| 11 | Dielectric withstand voltage | 3000 V AC / 1 min, primary to secondary |
| 12 | Insulation resistance | >= 1000 M ohm at 500 V DC |
| 13 | Operating temperature | -25 C to +85 C |
| 14 | Storage temperature | -40 C to +105 C |
| 15 | Window (aperture) diameter | Approx. 7 - 12 mm, customizable to busbar size |
| 16 | Housing material | Flame-retardant engineering plastic, UL94 V-0 |
| 17 | Potting | Epoxy resin, moisture and vibration resistant |
| 18 | Termination | Straight PCB pins or twisted flying leads with connector |
| 19 | Mounting method | PCB through-hole soldering or panel / bracket mounting |
| 20 | Compliance | RoHS compliant; CE / CB / UL / cUL available on request |
- Window (through-hole) structure: the primary conductor simply passes through the
aperture, no primary winding termination and no circuit interruption required. - Excellent linearity and low phase error, keeping measurement stable from light load
up to 120% of rated current. - Fully potted with epoxy resin inside a UL94 V-0 flame-retardant housing for strong
resistance to vibration, humidity, dust and electrical stress. - High isolation design with 3000 V AC withstand voltage between primary and
secondary, protecting the low-voltage measuring circuit from the power side. - Two termination options in the same footprint family: solder pins for automated PCB
assembly, or twisted leads with connector for quick harness plug-in. - Compact D-shaped low-profile body that saves valuable PCB area in space-limited
meters and control boards. - Wide turns ratio library (1000:1 to 5000:1) so one mechanical platform covers many
current ranges. - Stable temperature performance from -25 C to +85 C for indoor, cabinet and outdoor
enclosure installations. - Low insertion impact on the measured circuit, no additional heat generation on the
primary conductor. - Full customization: ratio, accuracy class, aperture, pin pitch, lead length, wire
gauge, connector model and label printing.
- Single-phase and three-phase energy meters, sub-metering modules and prepaid meters
- Smart power strips, smart sockets, smart breakers and residential energy monitors
- Solar inverters, energy storage systems and micro-inverter current feedback loops
- EV chargers and charging piles for output current monitoring and protection
- Switching power supplies and UPS units for overload and short-circuit detection
- Industrial control cabinets, PLC analog input modules and motor protection relays
- Building automation, HVAC systems and lighting control panels
- Leakage, overcurrent and residual current detection circuits
- Data center power distribution units (PDU) and branch circuit monitoring
- Home appliance and equipment load monitoring boards
- Established in 2000, with 26 years of continuous focus on magnetic components and
power solutions for industrial control and power electronics. - Own 10,000 sqm production base with 8 complete production lines, not a rented
workshop and not a trading company. - Annual transformer output of approximately 2,400KK pcs, giving stable capacity and
reliable delivery even in peak season. - Dedicated 20-person R&D team and 20-person QC team; engineering consultants with
over 26 years of practical design experience. - Annual export value of USD 42 million, serving North America (50%), Northern Europe
(18%), South America (15%) and Southeast Asia (15%). - Complete certification framework: ISO 9001 and ISO 14001 system certification, with
CE, CB, UL, cUL and RoHS product certification available. - Proven customer base including well-known appliance and signaling equipment brands
and North American inverter manufacturers. - Flexible trade support with DDP and DDU terms and payment by T/T, PayPal or
Western Union. - Full ODM / OEM service from schematic evaluation and sample building to mass
production, with MOQ from 1,000 pcs.
- Measurement accuracy classes down to 0.1, suitable for revenue-grade metering.
- Consistent batch-to-batch performance thanks to controlled core sourcing and
automated winding, reducing calibration workload on your production line. - High isolation and V-0 housing improve end-product safety certification readiness.
- Non-invasive window installation shortens assembly time and lowers labor cost.
- Compact footprint releases PCB space for other functional circuits.
- Epoxy potting keeps parameters stable under vibration and humidity, extending
field service life. - One platform, many ratios: easy to build a full product family without redesigning
the mechanical interface. - Engineering support on sampling resistor selection, burden matching and signal
conditioning circuit design.
Guangdong, China, with 8 complete production lines and in-house R&D and QC teams.
complexity of the structure, and we can discuss a suitable quantity for your project.
current, required turns ratio, accuracy class, aperture size and termination type,
and our engineers will confirm the sample plan with you.
time depends on quantity, ratio and termination type; we confirm an exact schedule
with each order and keep you updated during production.
length, connector model, housing size and label can all be customized. Send us your
drawing or target specification and we will provide a proposal.
including CE, CB, UL, cUL and RoHS are available; please tell us your target market
so we can confirm the applicable scope for your model.
voltage range of your ADC or metering IC. Share your rated current, target output
voltage and IC model, and our engineers will recommend a suitable resistor value and
burden configuration.
to sample building, testing and mass production, including customer logo marking.
cartons to protect them during transport. We ship by express, air or sea, and we
support DDP and DDU terms.
are shipped directly from our factory in China.
QC and R&D teams will analyze the samples, issue an analysis report and agree a
replacement or corrective action plan with you.

Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.