10 mm² vs 16 mm² Comb Busbar: How to Compare Cross-Section and Current Rating

A 16 mm² comb busbar has 60% more conductor cross-sectional area than a 10 mm² busbar because `16 ÷ 10 = 1.6`. That arithmetic does not establish a universal 1.6-times current rating. Select between them by comparing the exact manufacturer series and order rows for declared current, feed arrangement, terminal interface, pitch, poles, length, insulation system and stated installation conditions.

If the documentation only says “10 mm²” or “16 mm²” without identifying the exact busbar and compatible device system, the selection record is incomplete.

The 1.6× calculation—and where it stops

The conductor-area comparison is straightforward:

```text area ratio = 16 mm² ÷ 10 mm² = 1.6 area increase = (16 − 10) ÷ 10 × 100% = 60% ```

This tells an engineer or buyer that the nominal copper cross-section is larger. It does not calculate the permissible current of the assembled distribution system. A comb busbar is not an isolated rectangular copper sample: its teeth engage device terminals, its current enters at one or more feed points, and each section of the bar carries the current that remains downstream of that point.

The safe interpretation is therefore limited:

> 16 mm² provides 1.6× the nominal conductor area of 10 mm². The exact product documentation—not the area ratio—provides the usable current value and application limits.

Compare only like-for-like order rows

Before comparing current values, freeze the characteristics that are supposed to stay the same. A useful pair comes from one product family and keeps the following inputs aligned:

• pin, fork or other tooth interface;

• pole and conductor sequence;

• pitch and terminal geometry;

• finished length and number of positions;

• insulation and end-treatment system;

• device family and connection side;

• feed arrangement and relevant accessories;

• manufacturer's rating basis and stated conditions.

If any of these changes, the result is no longer a clean cross-section comparison. For example, a 16 mm² three-phase pin busbar and a 10 mm² single-phase fork busbar differ in much more than copper area. Their current markings cannot be used to create a 10-versus-16 conversion rule.

For the full input sequence, use How to Select an MCB Busbar. If the uncertainty is dimensional, the MCB busbar pitch guide shows how to document the contact pattern without assuming that nominal device width proves tooth spacing.

What named product data shows

Published product rows make the distinction between area and rating visible. The following examples are evidence for their named products only.

In the KASEEY P-2L-D example, the cross-section ratio is `16 ÷ 10 = 1.6`, while the published reference-current ratio is `80 ÷ 63 ≈ 1.27`. The purpose of this comparison is not to derive another universal factor. It demonstrates why the current value must be read from the corresponding product row.

The same KASEEY family also keeps a 17.8 mm device distance, 4 mm pin width and 11.5 mm pin length across the cited paired rows. Those matching fields make the pair useful for comparison, but they still do not prove compatibility with an unverified protective device.

Why current rating does not scale from area alone

Several linked constraints sit between conductor area and a released busbar assembly.

The connection is part of the current path

Current passes through the feed connection, copper bar, teeth and device terminal interfaces. A larger bar section does not repair a tooth that does not engage the intended clamp correctly or a terminal that is not approved for the combination.

Feed arrangement changes current distribution

The location and number of approved feed points affect how current is distributed along the comb. Cross-section alone does not describe which section carries which load. Use the manufacturer's approved arrangement and project calculation rather than treating every tooth as if it carries the same current.

Product construction and conditions remain relevant

Tooth geometry, insulation, conductor sequence, length, enclosure conditions and assembly instructions can all be part of the manufacturer's rating basis. A number copied from a visually similar product may have been declared under different conditions.

Protection and prospective fault duty are separate checks

A normal-current marking does not by itself prove short-circuit suitability, coordination with protective devices, or compliance of the completed assembly. These checks require the applicable device and busbar documentation, project fault data, and the responsible engineering process.

When 10 mm² remains the candidate

Keep the 10 mm² option under review when all of the following are true:

• the exact order model provides a declared value suitable for the design current and reviewed feed arrangement;

• the device manufacturer and busbar documentation support the terminal interface;

• pitch, pole pattern, tooth geometry, length and insulation requirements match;

• project-specific installation and protection checks are complete;

• the selected model, document revision and evidence are recorded.

Do not reject 10 mm² merely because 16 mm² exists. Oversizing the conductor section does not automatically solve a geometry, terminal or approval problem.

When 16 mm² remains the candidate

Keep the 16 mm² option under review when its exact product row and the complete assembly evidence support the required duty, and when the corresponding geometry remains compatible with the intended devices. It can also be the appropriate documented option when the required product family, project specification or approved design explicitly calls for that size.

Do not select it using the argument “60% more copper means 60% more current.” Also confirm that the 16 mm² order code is available in the required pole pattern, length and tooth system. A larger cross-section in a different configuration is not a substitute.

Stop conditions

Pause the selection and request controlled data if any of these conditions applies:

• the supplier quote lists only cross-section, not an exact series and order code;

• the current value is described without its basis or product row;

• the feed position or connection method is undefined;

• the busbar tooth and device terminal evidence conflict;

• pitch, poles, sequence, length or unused-tooth treatment is missing;

• the project needs short-circuit, temperature-rise or compliance evidence that has not been supplied;

• a value has been copied from another brand or superficially similar series.

These are evidence gaps, not reasons to guess a safety margin.

10 mm² vs 16 mm² comparison record

Copy this table into an RFQ, drawing review or engineering handoff. Complete both candidate columns before approving either one.

The record should make the decision traceable. “16 mm² is bigger” is not a traceable reason; “exact order model X, declared value Y, approved feed arrangement Z, compatible device evidence attached” is.

Select the documented assembly, not a standalone number

The practical difference is precise: 16 mm² has 60% more nominal conductor area than 10 mm², while the usable current value remains product- and assembly-specific. Compare matching order rows, preserve every interface and feed input, and stop when the supporting documents are incomplete.

Browse the KASEEY busbar range and the modular-device busbar system overview to identify a candidate family. To request a 10 mm² versus 16 mm² review, send the completed comparison record, device list, connection-side drawings, design current, feed arrangement, required length, quantity and destination market through the KASEEY contact page.

Technical references

• CHINT CBB-2 comb busbar product page

• CHINT CBB-2 official catalogue (PDF)

• Doepke DRCBO 4 busbars product table