Energy Regulations

IEC 60898-1 and IEC 60947-2: a tale of two standards

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In response to the question “What’s the difference between standards IEC 60898-1 and IEC 60947-2?”, I’m tending to answer with another question: What do they have in common?  They are both standards that specify requirements for low-voltage circuit breakers. Is there more in common? Let’s look into. 

Download for free the Electrical Installation Guide 2013!Which one if for homes, which one for industry?

IEC 60947-2, which I introduced at length in the first of these blog posts, governs CBs for industrial applications. They protect electrical power distribution of up to 1000 volts a.c. and 1500 volts d.c. with whole spectrum of rated current from 0,5 to 6300A. Utilities and manufacturing facilities use them: air circuit breakers (ACBs), molded case circuit breakers (MCCBs) and miniature circuit breakers (MCBs).
As for IEC 60898-1, it relates to the a.c. low-voltage circuit breakers – MCBs – we find in our homes, schools, shops, and offices electrical distribution switchboards. The standard states that the top rated current is 125A, while the lowest is 6A and maximum value of rated short-circuit capacity (Icn) is 25kA. Just those basic tech specs tell us how different the use of circuit breakers defined by our two standards are.

Many more differences and IEC 60898-1 and IEC 60947-2?

Yes. The rated voltage currently required in industrial-use CBs is 440, 690 volts or higher. Compare those numbers to the 400V upper limit between phases for residential MCBs.  Reference ambient temperatures are 30°C for households. The same goes for impulse withstand voltage (Uimp). IEC 60898-1 requires 4kV, in line with the use for final circuits. Whereas for industrial circuit-breakers, usual values of Uimp is 6 or 8kV, in line with the position of the circuit-breaker, at the origin of the installation.

Comparison table of characteristics of miniature circuit breakers (MCBs) usually used in the IEC market

Comparison table of characteristics of miniature circuit breakers (MCBs) usually used in the IEC market

Who confuses the two standards and how?

Users confuse – particularly “prescribers”, e.g. those people who draw up specifications in invitations to tender. Procurement managers in utilities, too, can get things wrong. As to how they mix up the standards, I can’t say. But happen it does.
The history of standard IEC 60947 may have something to do with it. The concept behind it as it evolved in 1970s-80s was a single standard for all low-voltage switchgear. That notion, combined with lack of knowledge or technical expertise, may have led to the misconception that there is one standard for all CBs. Of course, it wouldn’t matter so much if people thought it was IEC 60947-2.

Can IEC 60898-1 be used instead of IEC 60947-2?

No. Consequences can be dire if residential CBs are used instead of industrial ones. An MCB designed for indoor, pollution-free conditions would be woefully inadequate for harsh, outdoor applications that require pollution degree 3.
Or take the tripping characteristics: IEC 60898-1 clearly describes B, C and D curves with ratio to rated current, while in IEC 60947 2 the instantaneous tripping release may be adjustable according to the need of the user or pre-defined my manufacturer with ±20% tolerance. This is the reason why manufacturers in addition provide a wide scope of different curves: K, Z, MA.
Typically IEC 60898-1 certified CBs meet minimally required performance to proof proper protection of household installations: Pollution degree 2, impulse voltage 4kV, isolation voltage is the same as nominal voltage 400V. That is the reason why usually we meet limited number of printed technical information on CBs.

Example of Resi9 and Eazy9 circuit breakers for residential applications

Example of Resi9 and Eazy9 circuit breakers for residential applications

Where should be used IEC 60898-1 certified CBs?

These CBs are intended for use of indoor, pollution and humidity-free conditions: household or similar installations overcurrent protection by uninstructed people and not being maintained. In other words – in final distribution electrical switchboards of buildings which nominal current does not exceed 125A. Usually these circuit breakers sold by electrical retailers: simple to install, safe and easy to use even after many years without maintenance.

Example of Acti9 circuit breaker used for buildings and industry applications

Example of Acti9 circuit breaker used for buildings and industry applications

The most suitable solution for use are MCBs certified with both standards as their performance meets requirements of use for residential installations and high enough for use in industry and infrastructure applications. Due to high level of protection performances these CBs should be used at least in incoming electrical switchboards of buildings applications.

Appliance for MCB’s to standards in different applications of use

Appliance for MCB’s to standards in different applications of use

I can say is that mix-ups of standards happen. The best way to avert them is tightly worded, highly enforced national regulations. And for prescribers to specify what CBs will be used for and then to check the standard for that use.

Have you ever mixed up the two standards? Leave us your comments below!


56 Responses
  1. praseet

    I am from India. And I did engineering from electronics and communication in 2010. At present I am in search of job can you help me in getting job so that i can creat my future. ..

    Reply
    • Frank Lowe

      I am confused with two standards for the same breaker. Does it mean that the trip kA is different when the breaker is used for residential or non residential use? ICU and ICN. Also as i am new, how do i calculate my trip current ? Assuming the breaker is a 3 phase 230VAC, 63A.

      Reply
  2. Alan Sam

    I have never confused them yet maybe because its not much since I started working.Anyways the information was very useful and I’m sure I will need it in future.

    Reply
  3. FELIX Jr.

    INDEED , THERE WILL BE CONFUSION HERE AS MORE OFTEN THAN NOT THE IEC-60947 IS USED COMMONLY IN SPECIFYING LV SWITCHGEAR DESIGN AND IT’S COMPONENTS WHILE THE IEC-60898 IS NOT COMMONLY USED.

    THIS MUST BE HIGHLITED EVEN MORE BY IEC COMMITTEE TO AVOID ERROR.

    THANK YOU.

    Reply
  4. Stephen

    I have started working in the industrial sector and am having trouble completing test certs for installations fed from panels. How do I go about working out Max Zs Values for CB’s that have so many variables. The NICEIC just say refer to manufacturer, but I cant find the information for 60947-3 mcb’s starting from 2A and also for a lot of the motor starters GV2,3 etc etc. Can anyone help?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Stephen, the Max Zs value is not always published in technical guides. You should contact the technical support of Schneider Electric in your country.

      Reply
  5. Max

    Miniature Circuit Breaker – S200 – Number
    of Poles 1 – Tripping characteristic C
    Can these breakers be used with an inductive load?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Max, you should verify the inrush current of the inductive load first.
      Usually it is recommended to use D, K or MA curves MCB’s to protect inductive loads. Typically: C curve: Ii=5 to 10 In, D curve: Ii=10 to 14 In.

      Reply
  6. PAMBOS

    Shall any where mention on BS or IEC that we need to do Field Trip Test for each MCB’s type B,C,D .We are using SCHNEIDER MCB,s and the project is for housing.

    Reply
  7. Ricki

    Hi Vladislav

    I work for the utility in South Africa and am researching the use of MCB’s at the PUC between the utility and an IPP.

    Are AC MCB’s able to be used for DC applications? If so, What is it about the Ac rated MCB’s that makes this possible?

    Regards
    Ricki

    Reply
      • Ricki

        Hi Vladislav

        Thanks so much for the reply – very useful info.

        One last question:
        Are AC MCB’s polarity sensitive?

        My thinking is that by nature AC signals reverse polarity each cycle and therefore it would not matter which way the MCB was wired.

        Is this correct?

        Reply
        • Vladislav Tverdochleb Vladislav Tverdochleb

          Ricki, you are correct, there are no difference on MCB’s power supply side connection in AC applications.

          Reply
      • mehdi-mohammadian,iran

        hi Vladislav,
        to answer to ricki comment to use of MCB in DC current. I want to ask you that. can we use all AC MCB in DC voltage? free of voltage,current or curve.
        and that link is unavailable too.

        Reply
        • Vladislav Tverdochleb Vladislav Tverdochleb

          Dear Mehdi-Mohammadian,
          DC breaking conditions are different than AC.
          In order to use AC breaker in DC applications you should follow manufacturer recommendations. If such recommendations do not exist – its better to use dedicated DC offer.

          Reply
          • mehdi-mohammadian,iran

            I mean Schneider MCB’s. can you help me more about use of Schneider MCB in DC current. pleas send me by email.
            thanks a lot.

  8. Abdullah

    Really very useful information. Stil…
    1) Can we say it is for industrial application if a MCB manufactured as per IEC 60898 only
    2) According to these standards any manufacturers could provide life time warranty. Aging of Plastic covers, degradation of Bi-metals / Springs & No calibration for a long time as if it a life time product.

    Thanks

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Abdullah,
      As mentioned in the blog, MCB manufactured as per IEC 60898 to be used in residential buildings or similar applications. In industrial applications can be used breakers certified as per IEC 60947-2 or IEC 60947-2 and 60898 both.

      Reply
  9. sumedha

    I am in search of complete MCCB test procedure with graphical explanation. Kindly let me know if it is available on the Schneider site

    appreciate if Schneider can up load a youtube video

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Sumedha,
      Test procedures are explained in the mentioned standards. You can download them from official standardization bureau sites.

      Reply
  10. Amey Talekar

    What is the difference between short circuit values mentioned in the 2 standards , Icn values in IEC60898 & Icu value in IEC60947. There is also one observation that Icu values of MCB’s as per IEC60947 are higher than Icn values of MCB as per IEC60898.

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Amey,
      If I understood your question well, the difference comes from ratio of nominal Icn and ultimate Icu breaking capacities ratio to service breaking capacity Ics. It is usually stated in percentage 100%, 75%, 50% or less. As higher this value as more “robust” breaker to withstand Ics.

      Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Unfortunately I have no answer for the question. I would recommend to find the answer by contacting technical support team in the country.

      Reply
  11. SAHAD

    MCCB standard is IEC60947 and MCB is coming under IEC 947 & 898. So what is your opinion of using MCCB-947 & MCB-898 in a single distribution for a residential/commercial buildings. Also any problem occurs if using IEC898 MCB in industrial applications.

    Thanks

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Sahad, it is normal having MCCB certified as per 947 in commercial/small commercial buildings with MCB’s certified as per 898. And it is wrong to use MCB’s dedicated for domestic applications (60898) in industrial applications installations.
      In any case you should pay attention on technical characteristics of devices like: Icu, Ics, Ue, Uimp, pollution degree, ect.

      Reply
  12. raj

    Vlad,
    We use Siemens breakers and they have a SCCR rating of 10KA as per IEC 60898. Under IEC 60947 they do not mention any SCCR rating . But somewhere on the breaker it says Icu 20 KA . All in all there are so many interrupting ratings that I am so confused. All I need to know is are 5SY4232 breakers 10 KA rated for industrial AC application.
    Do you have DP breakers IEC certified for industrial application and 10 KA rated?

    Reply
  13. david

    Hi im looking for an MCB with the following specs please let me know if schneider offers one;

    standards IEC/EN 60898-1
    protection level IP20
    rated voltage and frequency 230v/400v 50hz,
    rated current 63A,
    break capacity of 6kva,
    1P+N,
    DIN rail mountable,
    35mm locking clip,
    thermal and magnetic trip function,
    operate under curve C,
    electrical life not less than 6000
    mechanical life not less than 20000

    Reply
  14. Kevin

    Dear Vlad,
    I found your article is very informative and helpful
    But I’m still confused in case of MCBs that have 2 condition of breaking capacity depend on which IEC that MCB comforting to

    Let’s take an example of MCB iC60N
    It have 6kA Icn conforming to IEC 60898-1 – 400 V AC 50/60 Hz
    and 50 kA Icu conforming to IEC 60947-2 – 380…415 V AC 50/60 Hz

    I am from Indonesia and we use 227 V Line to Netral / 400 V Line to Line
    When I use MCB iC60N which breaking capacity I should refer to?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Kevin,
      You should keep it simple: residential installations – IEC60898-1, industry and commercial buildings – IEC60947-2 & – IEC60898-1.

      In your given example its not exactly as you name it: for iC60N range the 50kA Icu is only for breakers in range of 0,5-4A, for the rest of the range it is 10kA.
      In fact it is about the same, eg. (iC60N, 6 to 63 A, 380…415 V AC 50/60 Hz):
      – as per 60898-1: Icn=6kA with Ics = 100% =>6kA
      – as per 60947-2: Icu=10kA with Ics = 75% =>7,5kA
      As you can see, breaker performs 7,5kA service capacity which is applicable for both standards requirements to declare.
      More details you can find in my blogs about 60947-2 standard (https://blog.schneider-electric.com/tag/iec-60947/)

      Reply
  15. Jonas

    Dear Vladislav

    IEC60947-2 used by MCCBs and IEC60898-1 are used by MCBs, is that correct?

    Can we consider iC60 a MCCB if the application is based on IEC60947-2?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Hello Jonas,
      No, your statement is not correct. MCB is a miniature circuit breaker and MCCB is a molded case circuit breaker. Difference is in the breaking technology and size.
      IEC60947-2 covers all the types of the breakers: MCB, MCCB, ACB
      IEC60898-1 naturally covers MCB’s due to limited nominal currents and breaking capacities stated in standard (In=<125A, Icn=<25kA)

      Reply
  16. Koks

    Hello Vlad, our customer need 10kAIC circuit breaker for Lighting / C.O. loads. Is it safe to offer the iC60n where it is 20kAIC at 230Vac,2P @ 947-2 standard and 6kAIC @ 898-1 standard?
    What is the right thing to say if they questioned us why we offered 6kAIC breaker?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Koks,
      Yes it is safe choice. iC60N 2P @230Vac during the trip has a double break effect (circuit is interrupting in 2 places, per each pole).
      It means at Isc=10kA 2P breaker is much reliable and can withstand up to Icu=20kA than 1P or 1P+N breakers (Icu=10kA).

      Reply
  17. M.O

    From your article I get that IEC 947-2 has stronger specs more than IEC 898-1 such as ( Ue , Ui , pollution degree) but how Icu for 947 ( stronger conditions ) can be greater than 898 for the same MCB

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Dear Mostafa, in IEC 898-1 it is mainly used definition of Icn (rated (nominal) breaking capacity) but not Icu (ultimate breaking capacity) and it makes the difference.
      Following IEC 898-1 ratio between Icn and Ics (service breaking capacity) shall be:
      – Icn ≤ 6 000 A – 100%
      – 6 000 A < Icn ≤ 10 000 A – 75% (Minimum value of lcs: 6 000 A)
      – Icn > 10 000 A – 50% (Minimum value of Ics: 7 500 A)

      Reply
  18. R.S

    Why marking on the the MCB are only based on a IEC 60898 standard And specification of MCB according to IEC 946-2 can be seen only in the data sheet?
    For example on the C60N

    Reply
  19. sumith

    I need to install 10kA breaking capacity MCB
    I have a MCB which shows Icn=6ka iec 60898 and Icu=10kA iec 60947
    Is it OK to use it

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Hello Sumith,
      If the field of installation is commercial buildings or industry, Icu=10kA is proper solution.

      Reply
  20. LIM FREDDIE

    MCB IEC 898-1 :10KA, IEC60947-2:15KA. Why is IEC60947-2 is higher at 15KA. If i need a MCB IEC60898-1: 15KA, is there such product from Schneider?

    Reply
    • Vladislav Tverdochleb Vladislav Tverdochleb

      Hello Lim,
      It is higher because of lower Icu breaking capacity ratio to service breaking capacity Ics, eg. 75% instead of 100%. In any case it will break 15kA.

      If you need 15kA according 60898-1, please check with local offer available, typically it is range of C120.

      Reply
  21. LIM FREDDIE

    Thanks for your reply. One more question regarding RCCB. The printed label on RCCB is either 6000A or 10000A. Understand that is making capacity and not Short Circuit capacity. What this 6000A or 10000A meaning. If my outgoing MCB is 10KA, them I should use a 10000A RCCB. Is this correct?

    Reply
  22. Owen Hsu

    I have a question regarding to the same MCB but different kA rating of different standard

    For example, the MCB marked 6kA @ IEC60898, and also marked 10kA @IEC60947-2, why does the manufacturer just marked 10kA@ both IEC60898 and IEC60947-2 if the testing procedure is the same C-t-CO

    Reply
  23. Sheldon

    HI
    I would like to know what have been the design and technological trend in low and medium current and high current miniature circuit breakers.
    I would really appreciate any help provided.

    Reply
  24. Dmytro

    Hi there,

    We have MCCB NSX 250H with Micrologic 2.2 trip unit installed in our utility station. We would like to connect 440V HPU with star-delta starter, inrush/peak start up current is abt. 448A, FLA is abt. 198A (HPU motor has it’s own overload protection). Is this breaker fit for purpose along with Micrologic 2.2 trip unit? What will be be approximate short-time delay timing for 448A inrush?

    Thanks

    Reply

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