The ZW32-12 is a 12 kV outdoor pole-mounted vacuum circuit breaker made by several Chinese companies, such as Chint and Ghorit. Combined with a recloser controller or FTU (feeder terminal unit), it works as a recloser: it opens on a fault, recloses and locks out if the fault persists. Rockwill is another brand of this type of equipment. It is installed on distribution networks and in industry.
What it is and where it is used
The ZW32-12 recloser is the combination of a 12 kV outdoor, pole-mounted vacuum circuit breaker with a recloser controller or FTU. It is made by several Chinese companies, among them Chint and Ghorit, and Rockwill is another well-known brand of reclosers of that origin. They are offered in export markets for distribution networks, rural taps and industry, often together with sectionalizers and fuse cutouts.
Its logic is that of any recloser: on a fault it opens, waits, closes again and, if the fault persists, locks out open. For the principle, see recloser and automatic reclosing 79. Chint also makes medium-voltage switchgear, described in Chint KYN28A cubicles and NG7 RMU, and string inverters for solar plants, in Chint Power CPS SCA and SCH inverters.
Variants: Chint and Ghorit ZW32-12, Rockwill and FTU
| Model | Application | Main difference |
|---|---|---|
| Chint ZW32-12 | Networks of 10 kV or less | Outdoor vacuum breaker, 630 A, 20 kA |
| Ghorit ZW32-12 | Distribution networks | 630 or 1,250 A, 20 or 25 kA |
| ZW32-12 with recloser controller | Recloser | Breaker plus FTU in a separate cabinet |
| FZW32-12 (Ghorit) | Sectionalizing | Vacuum load-break switch, not a recloser |
| Rockwill | Distribution reclosers | Another Chinese brand; data per its catalog |
Several factories use the same ZW32-12 designation; the actual performance depends on the manufacturer and is on the nameplate and the test report.
Main functions
| Function | ANSI | Comment |
|---|---|---|
| Phase and ground overcurrent | 50/51, 50N/51N | Main protection (guide) |
| Automatic reclosing | 79 | Clears transient faults and locks out on permanent ones (guide) |
| Sensitive ground | 50N/51N | On networks with high-impedance faults, if the FTU includes it |
| Over- and undervoltage | 59/27 | Depends on the controller (27 guide) |
The set of functions depends on the controller supplied with the equipment, which may come from a different manufacturer than the breaker.
Before energizing a new recloser, check the nameplate against the network (voltage, current and insulation level) and measure insulation and contact resistance. Opening and closing times are also checked. Finally, the controller is tested with secondary injection, to confirm that the curves and reclosing sequences are those of the study. See contact resistance test and circuit breaker timing test.
Communications and integration
The FTUs of this equipment usually communicate by IEC 60870-5-101/104, DNP3 or Modbus, over radio, cellular or fiber. The protocol and the signal map must be confirmed with the controller manufacturer before integrating the equipment into the utility SCADA. See IEC 60870-5-104 and radio and cellular links.
ZW32-12 datasheet values and standards
Ghorit’s product page (in English, with Chinese standards) describes the ZW32-12 as a three-phase 12 kV, 50 Hz vacuum circuit breaker for pole mounting. It has a one-piece pole (upper and lower) or an embedded pole, and two mechanism types: spring or permanent magnet. It is operated manually, electrically or remotely. Its published values:
| Parameter | Ghorit value |
|---|---|
| Rated voltage | 12 kV |
| Rated current | 630 A or 1250 A |
| Short-circuit breaking current | 20 kA or 25 kA |
| Peak withstand and making current | 40 kA or 50 kA |
| Short-time withstand current | 16 kA or 20 kA, 4 s |
| Rated operating sequence | O-0.3 s-CO-180 s-CO |
| Mechanical life | 10,000 operations (spring) or 30,000 (permanent magnet) |
| Short-circuit breaking operations | 500 |
| Closing / opening time | up to 75 ms / up to 50 ms |
| Lightning impulse | 75 kV, to ground and across open contacts |
| Power-frequency withstand voltage, 1 min | 42 kV dry and 34 kV wet |
Other figures from the same page: contact gap of 9 ± 1 mm, opening speed of 1.2 ± 0.2 m/s and closing speed of 0.6 ± 0.2 m/s, contact bounce of up to 2 ms, phase asynchronism of up to 2 ms and main circuit resistance of up to 80 µΩ. The declared service conditions are -35 to +45 °C, altitude below 1000 m, wind below 35 m/s and pollution level IV. The 1000 m limit and the 12 kV maximum voltage mean that altitude and insulation level must be checked before applying it on 13.2 or 13.8 kV networks.
Chint’s page for its ZW32-12 is more concise: it states a voltage of 3.6 to 12 kV, 630 A and 20 kA breaking current, conformity with IEC 62271-100 and IEC 62271-1, and refers to Chint’s download center for the full table. One manufacturer’s values cannot be carried over to the other, even if the designation is the same.
Chinese standards that appear in the datasheet. Ghorit cites IEC 62271-100, GB 1984, GB/T 11022, JB/T 3855 and DL/T 402. According to China’s national standards information platform, GB 1984-2003 was replaced by GB/T 1984-2014 (a modified adoption of IEC 62271-100:2008) and this, in turn, by GB/T 1984-2024, in force since April 1, 2025. DL/T 402-2016, a power-industry standard, replaced DL/T 402-2007 and applies to AC circuit breakers from 3 to 1000 kV; DL/T 403-2017 is the specific standard for vacuum circuit breakers. Anyone who receives a test report that cites “GB 1984” should treat it as an earlier edition and not as a current reference.
Primary and secondary integration in the Chinese market
In China this breaker is also offered as a “primary and secondary integration” package (一二次融合): Chinese manufacturers publish the pole-mounted ZW32-12 together with their field terminal (FTU) and, in some versions, with power taken from an external capacitor. That term describes a way of supplying the equipment and not an international standard, and it helps explain why many exporters offer the breaker “with FTU” and why the FTU documentation arrives separately, sometimes only in Chinese. In the purchase order, require the settings manual and the FTU software in a language the protection team can read, and a documented communication protocol.
Points of attention
- Two mechanisms, two mechanical lives. The figure of 30,000 operations corresponds to the permanent magnet; the spring mechanism is declared at 10,000.
- Altitude and pollution. The service limits of 1000 m and pollution level IV restrict its use in mountain regions and coastal areas.
- Nameplate values. Contact resistance, opening and closing times and phase synchronism are the three checks that compare the manufacturer’s test report with the commissioning measurements.
- Documents. A Chinese recloser without a test report and without the controller manual cannot be audited or set with documentary backup.
Frequently asked technical questions
- Manuals in your language: documentation and its language vary by manufacturer and distributor; the nameplate of the breaker and the FTU is the starting point.
- Controller software: each FTU has its own software; without it and without the password, the settings cannot be read or changed.
- Voltage and altitude: a 12 kV unit must not be installed on a higher-voltage network, and at high altitude the insulation is reduced.
- SCADA integration: the point map and the protocol must be tested before commissioning.
How we help
We do not sell reclosers. At Tiza Group we remotely configure and review recloser controls (settings, reclosing sequences and SCADA communication), test the equipment before energizing, and support commissioning in Colombia, or elsewhere on request, on distribution networks and in industry. See remote recloser configuration within remote relay configuration. If the recloser tripped or locked out with no clear cause, send us the event for a trip analysis. Write to us through contact.
Related guides
- Recloser
- Automatic reclosing 79
- Auto-reclose does not reclose
- Medium-voltage vacuum circuit breaker
- G&W Viper recloser
- Radial feeder protection scheme
- Entec EVR recloser and ETR300-R or EVRC2A-NT control
- Tavrida Rec15, Rec25, OSM recloser and RC5 control
- Eaton NOVA recloser and Form 4C, Form 5 and Form 6 control
- Chint KYN28A-12, KYN28A-24 cubicles and NG7 RMU
- Chint Power CPS SCA and SCH inverters
References
- IEEE C37.60 / IEC 62271-111, automatic AC circuit reclosers up to 38 kV.
- Chint, ZW32-12 product page.
- Ghorit, ZW32-12 and FZW32-12 datasheets.
- Manufacturer datasheets for ZW32-12 reclosers with recloser controller and FTU (Ningbo Tianan CHZ9-12, Jhkdq).
Frequently asked questions
What is a ZW32-12 recloser?
It is a three-phase, outdoor, pole-mounted 12 kV vacuum circuit breaker that becomes a recloser when it is paired with a recloser controller or FTU. Chint publishes it with 630 A and 20 kA breaking current for systems of 10 kV or less; Ghorit offers it with 630 or 1,250 A and 20 or 25 kA.
What is the FTU of a recloser?
FTU stands for feeder terminal unit. It is the electronic controller that measures currents and voltages, decides trips and recloses, and communicates with the control center. On Chinese reclosers it usually sits in a separate cabinet, connected to the breaker by cable, together with a voltage transformer for the power supply.
Can a ZW32 recloser be used on 13.2 kV or 34.5 kV networks?
The ZW32-12 designation corresponds to 12 kV, so it is not suitable for 13.2 kV or 34.5 kV unless the manufacturer confirms a higher-voltage version. Before buying or installing, check the rated voltage, the insulation level and the site altitude on the nameplate and the test report.