AC MCB Selection Guide: Current, Poles, Trip Curve and Breaking Capacity

Two breakers with a similar current range may differ in:

• voltage
• pole configuration
• available trip-curve options
• breaking capacity
• mounting format
• exact product configuration

These differences matter when sourcing MCBs for an electrical panel, OEM project or replacement requirement.

The most useful approach is not to search for one universal rule such as:

“Use this curve for this load.”

or:

“6kA is enough for this application.”

Those decisions depend on the actual electrical system and confirmed engineering requirements.

A better sourcing process is to define the required parameters first, then compare them against the published data for the exact MCB model.

This guide explains how to evaluate the current RITOKS AC MCB range using five practical selection inputs:

• current rating
• pole configuration
• trip-curve availability
• breaking capacity
• mounting and exact-model verification

In This Guide

• Quick AC MCB Selection Summary
• Required AC voltage
• Current rating
• Pole configuration
• Trip-curve availability
• Breaking capacity
• Mounting format
• Selection process
• Frequently Asked Questions

Quick AC MCB Selection Summary

Selection Factor	What to Confirm	Current RITOKS Published Examples
Voltage	Required AC system voltage	230/240V AC and 230/400V AC product families
Current	Required breaker rating	Published variants from 1A to 63A overall
Poles	Required physical configuration	1P, 1P+N, 2P, 3P, 3P+N and 4P depending on model
Trip Curve	Which curves are offered on the exact product	B/C or B/C/D depending on model
Breaking Capacity	Published value for the selected product or variant	1kA, 6kA, or 10kA examples depending on model
Mounting	Mechanical installation format	Current products use 35mm or 35.5mm DIN-rail formats

These are product-selection inputs, not universal electrical-design rules.

For available models, see the RITOKS Miniature Circuit Breakers (MCB) range within AC Power Protection.

1. Start With the Required AC Voltage

Voltage should be one of the first filters when comparing AC MCBs.

Current RITOKS published products include different voltage families.

For example:

• RTSXD01 — AC 230/400V
• RTSXD03 — AC 240V
• RTSXD02 — AC 240V
• RTSXD04 — AC 230/400V
• RTS-ACM60 — 230/240V AC
• RTS-AC47 — 230/400V AC

This means two breakers with similar current ratings may still be intended for different published voltage configurations.

The correct sequence is:

system requirement → candidate product → exact model confirmation

rather than selecting a breaker from current alone.

2. Select the Current Rating From Confirmed Model Options

The current RITOKS AC MCB range contains published variants from 1A to 63A overall, but those ranges are not identical across every product family.

Examples include:

RTSXD01

The RTSXD01 family publishes 1–63A variants, AC 230/400V and multiple pole configurations.

RTSXD02

The RTSXD02 family publishes 1–32A, AC 240V and 1P+N.

RTSXD03

Published range: 1–32A, AC 240V and 1P+N.

RTS-ACM60

The RTS-ACM60 family publishes 6–63A, 230/240V AC and 1P / 2P.

RTS-AC47

The RTS-AC47 family publishes 10–63A, 230/400V AC and 1P / 2P / 3P / 4P.

The current value therefore helps identify possible models, but it does not complete the selection.

A published 32A option in one family should not be assumed to have the same pole, curve, breaking-capacity or installation configuration as a 32A option in another family.

Current Rating Is Not a Cable-Sizing Rule

One important distinction should be kept clear.

An MCB product page may publish available current ratings.

That does not mean the product page alone establishes:

• the required conductor size
• the correct load calculation
• protective coordination
• allowable derating
• the correct breaker size for every installation

Those engineering decisions depend on the actual system and applicable design requirements.

For sourcing purposes, the current rating should be treated as one confirmed product parameter to compare against the buyer’s already-defined requirement.

3. Check the Pole Configuration

Pole configuration is another practical selection factor.

Current RITOKS published AC MCB families include several different physical options:

• 1P
• 1P+N
• 2P
• 3P
• 3P+N
• 4P

But not every model offers every configuration.

For example:

• RTSXD01: 1P+N, 2P, 3P, 3P+N and 4P
• RTSXD02 and RTSXD03: 1P+N
• RTS-ACM60: 1P and 2P
• RTS-AC47: 1P, 2P, 3P and 4P

This means pole configuration can quickly narrow the candidate product families.

Pole Count Should Not Be Selected From a Generic Rule

The available product configuration and the required electrical configuration are two different questions.

RITOKS product data can tell a buyer:

Which pole versions are available?

But it does not by itself establish:

Which conductor or neutral arrangement a particular electrical system must use?

That depends on the actual circuit and engineering requirements.

So the practical sourcing workflow is:

1. define the required pole configuration
2. identify products that offer it
3. verify the exact model and documentation

4. Understand Trip-Curve Availability Without Overgeneralizing

Trip curve is an important MCB selection parameter, but this is also an area where overly simple advice can become misleading.

Current RITOKS product data confirms:

• RTSXD01: B / C / D
• RTSXD03: B / C
• RTSXD02: B / C
• RTSXD04: B / C / D
• RTS-ACM60: B / C
• RTS-AC47: not confirmed

This means RITOKS currently has published MCB families with B and C options, B/C/D options, and one family where the curve has not yet been confirmed.

What this data does not establish is a universal rule assigning each curve to a specific load.

B Curve vs C Curve vs D Curve: What Can Be Said Safely?

B, C and D are different trip-curve designations.

However, the current RITOKS website does not provide the complete time-current data needed to build a model-specific engineering comparison of:

• operating thresholds
• exact instantaneous-trip behavior
• time-current response
• load-specific curve recommendations

Therefore, the safest sourcing approach is:

1. identify which curve the project requires
2. check whether the candidate MCB family offers that curve
3. verify the exact product documentation before ordering

For example, if a buyer requires a D-curve option, the current published data shows that RTSXD01 and RTSXD04 list B/C/D options, while RTSXD02, RTSXD03 and RTS-ACM60 currently list B/C.

That is a valid product-family comparison.

It is different from claiming that one curve is universally correct for a certain application.

5. Check Breaking Capacity on the Exact Model

Breaking capacity is another important product parameter that must remain tied to the exact MCB.

Current published examples include:

• RTSXD01: 10kA Icn / 7.5kA Ics
• RTSXD04: 10kA Icn / 7.5kA Ics
• RTSXD02: 6kA
• RTSXD03: 6kA
• RTS-ACM60: 6kA published as typical; exact variant should be confirmed
• RTS-AC47: 1kA

These differences provide useful sourcing information.

But they should not be converted into statements such as:

6kA is for residential applications.

or:

10kA is always required for industrial panels.

The required breaking capacity depends on the actual fault-duty conditions and project requirements.

The RITOKS product data can help identify which models publish a required value after that requirement has been established.

6kA vs 10kA: What Does the Product Data Tell Us?

The current product range shows that RITOKS offers both 6kA and 10kA MCB families.

That allows a buyer to shortlist products based on a required breaking-capacity specification.

For example:

• If the RFQ specifies a confirmed 10kA requirement, current published candidates include RTSXD01 and RTSXD04.
• If the RFQ specifies 6kA, current published candidates include RTSXD02 and RTSXD03.
• RTS-ACM60 also publishes 6kA as typical, but the exact selected variant should be confirmed before treating that value as final.

This is the correct role of product data:

match a defined engineering requirement to a confirmed product configuration.

The product catalog should not be used to invent the engineering requirement itself.

6. Consider the Mounting Format

All six current AC MCB families use DIN-rail mounting formats.

Published examples include:

• 35mm DIN rail
• 35.5mm DIN rail

This makes them relevant to modular electrical-panel installations designed around compatible DIN-rail arrangements.

But even where two MCBs use DIN-rail mounting, they may still differ in:

• poles
• current range
• voltage
• trip-curve options
• breaking capacity
• family configuration

Mounting compatibility alone is therefore not enough to establish full interchangeability.

AC MCB Families at a Glance

Model	Voltage	Current	Poles	Curve	Breaking Capacity
RTSXD01	AC 230/400V	1–63A	1P+N, 2P, 3P, 3P+N, 4P	B/C/D	10kA Icn / 7.5kA Ics
RTSXD03	AC 240V	1–32A	1P+N	B/C	6kA
RTSXD02	AC 240V	1–32A	1P+N	B/C	6kA
RTSXD04	AC 230/400V	1–63A	1P+N, 2P, 3P, 3P+N, 4P	B/C/D	10kA Icn / 7.5kA Ics
RTS-ACM60	230/240V AC	6–63A	1P, 2P	B/C	6kA typical; confirm variant
RTS-AC47	230/400V AC	10–63A	1P, 2P, 3P, 4P	Not confirmed	1kA

This table summarizes current published product data. It should not be interpreted as a complete engineering interchangeability table.

A Practical AC MCB Selection Process

A useful sourcing workflow is:

1. Confirm the system voltage. Identify the required AC voltage before comparing breaker families.
2. Confirm the required current rating. Use the project requirement to narrow candidate MCB models.
3. Confirm the pole configuration. Define whether the project requires 1P, 1P+N, 2P, 3P, 3P+N or 4P, then compare only products that publish that configuration.
4. Confirm the required trip curve. If the project already specifies B, C or D curve, identify which MCB families publish that option. Do not substitute one curve for another without confirming the project requirement.
5. Confirm the required breaking capacity. Use the specified breaking-capacity requirement to filter products and keep the value attached to the exact model or variant.
6. Confirm mounting and mechanical fit. Verify the DIN-rail format and installation requirements.
7. Verify the exact product documentation. Before ordering, confirm the final model, configuration and any required supporting documentation.

Selection Examples

Example 1: A 1P+N Requirement

Suppose an OEM panel specification already calls for:

• AC 240V
• 1P+N
• a current option within 1–32A
• B or C curve
• 6kA breaking capacity

Current published RITOKS candidates include RTSXD02 and RTSXD03.

Both publish those headline selection parameters.

The buyer can then compare the exact model documentation, series positioning and other confirmed project requirements.

This example does not mean every 1P+N circuit should use these values.

It simply demonstrates how a defined specification can be matched to available product data.

Example 2: A B/C/D Curve Requirement

Suppose a project requires the ability to source B, C and D curve versions within one MCB family.

Current published options include RTSXD01 and RTSXD04.

Both currently publish:

• AC 230/400V
• 1–63A variants
• multiple pole options
• B/C/D curve availability
• 10kA Icn / 7.5kA Ics

The final configuration still needs to be confirmed by exact model and project requirement.

Example 3: A 1P or 2P DIN-Rail Family

If the project requires a simple 1P or 2P DIN-rail family, the RTS-ACM60 range may be a candidate.

Published characteristics include:

• 230/240V AC
• 6–63A variants
• 1P / 2P
• B/C curve
• 35mm DIN rail

Its 6kA value is published as typical and should be confirmed for the selected variant before final specification.

Common AC MCB Selection Mistakes

• Selecting from current rating alone. A 32A or 63A label does not tell you the voltage, pole configuration, trip curve or breaking capacity.
• Assuming every product offers B, C and D curves. Some current products list B/C/D, some list B/C, and one does not have a confirmed curve on the site.
• Treating 6kA and 10kA as application labels. Breaking capacity is a product parameter, not a shortcut that automatically defines the application.
• Assuming similar appearance means equivalent configuration. DIN-rail MCBs may look similar while offering different electrical and mechanical configurations.
• Generalizing one model’s data across the range. A rating published for RTSXD01 should not automatically be applied to RTSXD02, RTS-ACM60 or another family.
• Using the MCB catalog to perform cable sizing. Product current ratings do not replace the engineering process used to determine conductor sizing and protective-device coordination.
• Treating “Economic,” “Standard” or “Pro” as universal performance rankings. Use the confirmed specification of the exact product instead of unsupported assumptions about quality, lifetime, protection performance or application suitability.

What Information Should Be Included in an AC MCB RFQ?

A clear AC MCB RFQ checklist makes product matching much easier.

At minimum, consider including:

• required AC voltage
• required current rating
• pole configuration
• required trip curve, if specified
• required breaking capacity
• DIN-rail or mounting requirement
• quantity
• application or panel context
• required documentation
• packaging or OEM requirements if relevant

With these inputs, the inquiry can be matched against available RITOKS MCB families without relying on assumptions.

Frequently Asked Questions

How Do I Choose the Current Rating of an MCB?

Start with the current rating already defined by the project or electrical design, then identify MCB models that publish that rating. Product-page current options should not be used as a substitute for load calculation or cable sizing.

Does RITOKS Offer B, C and D Curve MCBs?

Current published RTSXD01 and RTSXD04 families list B/C/D curve options. RTSXD02, RTSXD03 and RTS-ACM60 currently list B/C options. The trip curve for RTS-AC47 is not confirmed on the current site.

Is 10kA Better Than 6kA?

Not as a universal statement. They are different published breaking-capacity values. The required value depends on the electrical system and project requirements.

Can I Choose MCB Poles Based Only on the Number of Wires?

The current product range shows which pole configurations are available, but it does not establish universal circuit or neutral-switching rules. The required pole configuration should come from the system design.

Are All 63A MCBs the Same?

No. Different 63A-capable product families may differ in voltage, poles, trip-curve availability, breaking capacity, mounting and other configuration details.