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Views： 5 Author： Mark Zhang Publish Time： 2026-08-08 Origin： 本站
The DZ30 (3KA) miniature circuit breaker from SINGI delivers dependable overamperage and short-circuit protection for light commercial and residential electrical systems. This article discusses choice criteria, technical features, and compliance for engineers and buyers. View the full SINGI miniature circuit breaker range for specifications.
The DZ30 (3KA) is a miniature circuit breaker designed to interrupt overloads and short circuits in single-phase and three-phase low-volt-level circuits. Its thermal-magnetic trip mechanism responds to sustained overcurrents and instantaneous high-amperage faults. During a short circuit, the breaker opens the circuit before sustained arcing damages downstream equipment. The 3kA rated breaking capacity means the device can safely interrupt fault currents up to 3000 amperes under specified test conditions.
Because it is a modular DIN-rail device, the DZ30 (3KA) integrates into distribution boards, metering cabinets, and control panels. It is used in retail stores, small offices, lighting circuits, and HVAC systems where fault amperage levels remain moderate. Engineers should confirm that the prospective short-circuit amperage at the installation point does not exceed the breaker's rating.
Note: The DZ30 (3KA) is intended for alternating amperage circuits. For DC applications, a separately listed DC-rated miniature breaker with appropriate polarity and arc extinction design is required.
Not every circuit needs a high-breaking-capacity breaker. Many residential and light commercial distribution boards have a transformer rating or supply impedance that limits short-circuit amperage to under 3kA. Choosing a DZ30 (3KA) in these conditions provides an economic solution without sacrificing safety. The 3kA rating is suitable for final circuits where the upstream protective device, such as a main switch or service fuse, limits fault current.
Using a breaker with a breaking capacity higher than necessary increases cost and physical size in some cases. For straightforward installations without high fault amperage availability, the DZ30 (3KA) offers a compact and cost-effective option. Sizing the breaking capacity correctly is as critical as the amperage rating itself. According to IEC 60898-1, the rated breaking capacity represents the maximum-val fault amperage the circuit breaker can interrupt under prescribed test conditions.
The DZ30 (3KA) uses a contact arrangement and arc-extinguishing system tailored for rapid amperage limitation. Its current-limiting design forces the arc into a splitter plate stack within milliseconds, reducing thermal stress on downstream components. The trip unit combines a bimetallic strip for overload protection and an electromagnetic coil for short-circuit protection. This dual action meets the requirements of overamperage protection standards.
The housing is molded from flame-retardant thermoplastic, and the terminal layout accommodates standard copper conductors. The breaker also provides visible contact position indication, which helps maintenance personnel confirm the circuit state. For installers, the DIN-rail clip allows quick mounting and removal. The product complies with the test requirements of IEC 60947-2 when applied in industrial control panels, and with IEC 60898-1 for household and similar installations.
The DZ30 (3KA) is used in circuits where the prospective short-circuit amperage is 3kA or lower. Typical applications include:
These installations receive power from a low-capacity transformer or a long supply cable, both of which reduce fault current. Buyers should still perform a short-circuit calculation to confirm that the available fault amperage at the breaker's terminals is within 3kA. If the system expansion may increase fault level, choosing a higher-rated breaker or adding current-limiting upstream protection is advisable.
Engineers and procurement teams should check the following details when specifying the DZ30 (3KA):
For distribution boards, the C-curve is most common because it balances overload tolerance with short-circuit response. B-curve breakers are chosen for purely resistive loads, while D-curve models handle inrush currents from motors and transformers. The SINGI product page provides a choice table that includes the DZ30 (3KA) with technical data. Use the project's short-circuit study to verify that the 3kA rating is sufficient.
| Parameter | DZ30 (3KA) | Typical 6kA MCB | Typical 10kA MCB |
|---|---|---|---|
| Rated breaking capacity | 3,000 A | 6,000 A | 10,000 A |
| Common applications | Residential and light commercial | Commercial and small industrial | Industrial and high-fault locations |
| Cost | Lower | Moderate | Higher |
| Physical size | Compact | Standard | May be longer |
| Typical tripping curves | B, C, D | B, C, D | B, C, D |
Choosing a 3kA breaker is acceptable only when the installation's maximum-val fault amperage is proven to be below that level. For circuits with uncertain supply capacity or planned upgrades, a higher-rated breaker provides extra margin. The DZ30 (3KA) remains a viable choice for OEMs and contractors who standardize on low-fault designs.
It can be used as a feeder breaker only if the available short-circuit amperage at that point is not higher than 3kA and the amperage rating is within the breaker's range. For main incomers with higher fault levels, choose a breaker with a larger breaking capacity.
B-curve breakers trip between 3 and 5 times the rated current, making them suitable for resistive loads. C-curve breakers trip between 5 and 10 times the rated current, making them a good match for inductive loads and general distribution.
No. A miniature circuit breaker protects against overamperage and short circuit. For protection against earth leakage and direct contact, an RCD or RCBO is required.
Calculate the prospective short-circuit amperage at the breaker's location using the supply transformer impedance and cable resistance. This value must be less than 3kA. If unsure, consult the local utility or an electrical design engineer.
The DZ30 (3KA) miniature circuit breaker from SINGI offers a cost-effective and reliable protection solution for circuits with limited fault current. Its compact design, DIN-rail mounting, and thermal-magnetic operation make it suitable for residential and light commercial applications. Confirm the prospective short-circuit current, pole configuration, and tripping characteristic before ordering.
For project specifications or quantities, visit the SINGI miniature circuit breaker category and choose the DZ30 (3KA) model. For technical documentation, contact the representative or request the datasheet from the product page.
Request a quote for the SINGI DZ30 (3KA) today. The product page includes mounting dimensions, trip curve data, and certification details. Engineers and procurement teams can download the datasheet or send an inquiry for bulk pricing.
