Miniature Circuit Breaker Supplier
Miniature Circuit Breakers for Zuverlässiger Schaltungsschutz
Select a DIN rail MCB from the actual system voltage, load current, conductor capacity, trip curve, poles and prospective short-circuit current. SENTOP supports model review, samples, OEM requirements and bulk supply for distribution boards and electrical equipment.
MCB Protection Function
What does a miniature circuit breaker protect?
A Leitungsschutzschalter automatically opens a circuit when current exceeds its defined time-current characteristic. A thermal element responds to sustained overload, while a magnetic element responds rapidly to high short-circuit current.
The MCB is selected primarily to protect conductors and connected circuits. It must be coordinated with cable capacity, load behavior, upstream protection and the available fault current at the installation point.
Überspannungschutz
The thermal release responds with a time delay when current remains above the permitted range. Exact operation follows the model's time-current data and reference conditions.
Kurzschluss-Schutz
The magnetic release trips rapidly at a multiple of rated current. The B, C or D characteristic changes this instantaneous operating range.
Manual isolation and reset
After the fault is found and cleared, a resettable MCB can be manually reclosed. Do not repeatedly reset a breaker without identifying the trip cause.
Miniature Circuit Breaker Selection
Choose the MCB from the Schaltung, not amperes alone
The rated current printed on the front is only one selection value. A correct MCB must protect the conductor, tolerate normal inrush and safely interrupt the fault level available at its installation point.
Systemspannung und Stromart
Schichtannahme AC oder DC, rated voltage, frequency, earthing arrangement and the voltage seen by each pole. Use only a model with matching voltage and current-type ratings.
Load and design current
Identify continuous current, duty cycle, startup current, harmonics and expected operating temperature. Do not increase the breaker rating simply to stop nuisance tripping.
Leiterkapazität
Coordinate conductor material, cross-section, insulation, installation method, grouping and ambient temperature. The protected conductor must remain within its permitted current.
Reisecharakteristik
Choose B, C or D from the load's inrush behavior and the required fault disconnection performance. Confirm that the available fault current can operate the selected curve within the required time.
Pole und neutrale Behandlung
Match the device to the phase system and required conductor isolation. Check which poles are protected, which are switched and whether the neutral is solid or switched.
Schaltvermögen
The rated short-circuit capacity must be at least the prospective short-circuit current at the installation point, unless a documented backup protection arrangement applies.
Standard and target market
Confirm the required product standard, approval, markings and document package for the destination. Product availability and certification are verified by exact model.
DIN Rail MCB Product Directions
Select poles from the Vertriebssystem
The images show common modular directions. Final rated current, voltage, curve, breaking capacity, protected poles, dimensions and approvals are confirmed from the exact model code.
1-Pole MCB
A compact direction for protecting one phase conductor in a circuit where the system design permits the neutral to remain unswitched.
2-Pole MCB
A mechanically linked two-pole direction for single-phase or specified DC circuits where two conductors must open together.
3-Pole MCB
A linked three-pole direction for three-phase circuits where all phase conductors require coordinated protection and simultaneous operation.
4-Pole MCB
A four-pole direction for systems that require coordinated opening of three phase conductors and the neutral according to the project design.
Also available by requirement: 1P+N and 3P+N arrangements may provide different protection and switching behavior from fully protected 2P or 4P devices. Confirm the pole diagram and model documentation before substitution.
MCB Tripping Characteristics
Match B, C or D curve to the load inrush
The curve letter does not describe overall product quality. It identifies the instantaneous magnetic trip range. Thermal overload behavior, ambient conditions and the complete time-current curve must also be considered.
Typ B MCB
Commonly considered for resistive or low-inrush circuits where faster magnetic operation is appropriate.
Typ C MCB
A common direction for mixed commercial and industrial loads with moderate starting or switching current.
MCB Typ D
A direction for loads with high but expected startup current, subject to fault-current and disconnection-time verification.
The 3-5, 5-10 and 10-20 multiples are the IEC/EN 60898-1 instantaneous ranges commonly associated with B, C and D characteristics. Use the exact manufacturer's time-current curve, installation rules and protection study for final design.
Breaking Capacity, AC/DC and Standards
Confirm what the front marking bedeutet eigentlich
Ratings are linked to a specific standard, voltage, number of poles and test condition. Similar front dimensions do not make two breakers interchangeable.
6 kA oder 10 kA
Choose from the prospective short-circuit current at the installation point and the applicable standard. A higher number is not a substitute for a fault calculation or coordination check.
AC-rated MCB
Use within the stated AC voltage, frequency and pole arrangement. Confirm how the rated short-circuit capacity changes with system voltage.
DC-bewerteter MCB
DC interruption is model-specific. Confirm rated DC voltage per pole, polarity, required poles in series, wiring direction and the intended DC application.
Backup-Schutz
Any cascading or backup arrangement must be documented for the exact upstream and downstream devices, voltage and fault level. Do not infer it from current ratings.
Erinnerung an das nordamerikanische Projekt
UL 489 branch-circuit breakers and UL 1077 supplementary protectors have different intended functions. Confirm the required listing and installation role instead of treating them as equivalent DIN rail products.
| Auswahlartikel | Was zu überprüfen ist | Warum es wichtig ist |
|---|---|---|
| IEC / EN 60898-1 | AC MCB rating, Icn, curve, current, voltage and target-market acceptance | Common basis for household and similar installation circuit breakers intended for operation by uninstructed people |
| IEC / EN 60947-2 | Industrial circuit-breaker data including Icu, Ics, utilization and installation conditions | Applies to industrial circuit breakers intended for use by instructed or skilled people |
| Bemessungsspannung | AC or DC value, voltage per pole and pole arrangement | Short-circuit performance and safe interruption depend on operating voltage |
| Bemessungsstrom | Load, cable capacity, ambient temperature, enclosure and grouping | The printed ampere value is referenced to defined conditions |
| Schaltvermögen | Icn, Icu oder ichcs as applicable, at the project voltage | The device must interrupt the prospective fault current safely |
| Reisecharakteristik | B, C, D or another model-specific curve and its complete time-current data | Controls inrush tolerance and fault disconnection behavior |
| Zulassungen | Certificate owner, model scope, standard edition, marking and target market | Approval is confirmed per exact model, not by product appearance or family name alone |
Miniature Circuit Breaker Applications
Define the MCB from the angeschlossener Stromkreis
The same rated current can serve very different loads. Inrush, duty, conductor arrangement, fault level and environmental conditions must be reviewed for each application.
Beleuchtungs- und Steckdosenstromkreise
Confirm load diversity, cable capacity, driver or power-supply inrush, earth-fault protection and local installation rules.
Kommerzielle Verteilerkästen
Coordinate outgoing circuits with upstream devices, prospective short-circuit current, selectivity needs and board temperature.
Control cabinets and machinery
Review transformer, contactor, power supply and motor inrush together with control-circuit conductor protection.
Kleinmotorschaltungen
Check starting current, starting time, overload protection method and whether an MCB alone provides the required motor protection.
DC and photovoltaic auxiliary circuits
Use a specifically DC-rated model and verify system voltage, polarity, number of poles, isolation and backup protection.
Elektrische OEM-Ausrüstung
Standardize the approved model, terminal method, accessories, label, documents and repeat-order reference for equipment production.
Miniature Circuit Breaker RFQ
Send the circuit details for an accurate MCB quotation
You can begin with a model, nameplate photo, distribution-board schedule or basic electrical requirements. We will identify the remaining details that must be confirmed.
Beschreiben Sie den Schaltkreis.
AC or DC, voltage, frequency, phase system, load type, design current, startup current, conductor and installation method.
Schutz definieren
Poles, curve, breaking capacity, prospective fault current, upstream device, residual-current protection and required standard.
Bestätige die Bestellung
Model or replacement reference, quantity, destination, certificates, accessories, OEM label, packaging and delivery schedule.
MCB Model Verification and Bulk Supply
Erstellen Sie wiederkehrende Bestellungen rund um ein approved reference
For distributors, panel builders and equipment manufacturers, purchasing consistency depends on more than a similar housing. The model code, ratings, internal configuration, markings and order documents must stay aligned.
Related Circuit Protection Resources
Setzen Sie die Planung fort komplettes Schutzsystem
Miniature Circuit Breaker FAQ
MCB selection questions
Use these answers to prepare the technical information required for model matching and procurement.
How do I choose the correct miniature circuit breaker?
Confirm AC or DC system voltage, frequency, load type, design current, conductor capacity, trip curve, poles, prospective short-circuit current, required breaking capacity, upstream protection, target-market standard and installation conditions. The rated current alone is not enough.
What is the difference between Type B, C and D MCBs?
Under IEC/EN 60898-1, Type B has an instantaneous range of 3 to 5 times rated current, Type C 5 to 10 times, and Type D 10 to 20 times. Higher inrush tolerance also requires enough fault current to achieve the required disconnection time.
Should I choose a 6kA or 10kA MCB?
Choose from the prospective short-circuit current at the installation point, the applicable product standard and any documented backup protection. The MCB short-circuit capacity must be adequate for the available fault current at the project voltage.
Can an MCB protect people from electric shock?
An ordinary MCB provides overcurrent protection and does not detect small residual currents. Use the required RCD, RCCB or RCBO for residual-current or additional shock protection, coordinated with local electrical rules.
Does an MCB protect against voltage surges?
No. A standard MCB is not a surge protective device. Use a correctly selected and coordinated SPD where protection from transient overvoltage caused by lightning or switching events is required.
Kann ein AC-Leitungsschutzschalter in einem DC-Stromkreis verwendet werden?
Only when the exact manufacturer data explicitly assigns a suitable DC rating and wiring arrangement. Otherwise use a DC-rated MCB and confirm voltage per pole, polarity, poles in series and the intended DC application.
What is the difference between 1P+N and 2P?
The protection and switching arrangement can differ. A 1P+N device may protect one pole while switching the neutral, whereas a 2P device may protect both poles. Always check the pole diagram and datasheet for the exact model.
Why does an MCB trip when equipment starts?
The equipment may have a normal inrush current that enters the MCB's instantaneous trip range, or the circuit may have overload, a short circuit, incorrect wiring or a defective load. Measure and diagnose the cause before changing the curve or increasing the rated current.
Can an MCB be reset after it trips?
Yes, an MCB is manually resettable after the fault has been identified and cleared. It does not normally reset itself. Repeated tripping should be investigated rather than repeatedly reclosed.
What information is needed for an MCB replacement?
Send the full model and front marking, clear photos, AC or DC system data, current, curve, poles, breaking capacity, dimensions, busbar and terminal arrangement, upstream device, target standard and required quantity. A similar case shape does not confirm compatibility.
Can SENTOP support OEM and bulk MCB orders?
Eligible models can be reviewed for samples, repeat supply, labels, packaging, documentation and other OEM requirements. Feasibility, approval scope, quantities and technical impact are confirmed for the requested model and destination market.
Miniature Circuit Breaker Supply Support
Send your MCB model, panel schedule or circuit requirements
SENTOP can review DIN rail miniature circuit breaker requirements for model matching, replacement, samples, OEM electrical equipment, distributor ranges and bulk orders.
