When buying semiconductor fuses, it is easy to focus on the rated voltage, current and price.
Certification is often checked later, sometimes only when the fuse is already being considered for a project.
That can cause problems.
A semiconductor fuse may be used in an inverter, power converter, energy storage system or other equipment where the protection requirements are quite specific. The manufacturer may have many certificates, but that does not mean every fuse in its catalog is covered by the same certification.
So the better question is not simply, "Does this manufacturer have certificates?"
It is:
Does the fuse I am buying have the standard and certification required for my application?
Start with the product standard
For semiconductor fuses, IEC 60269-4 is one of the main standards buyers will come across.
It applies to fuse-links intended for the protection of semiconductor devices. When a fuse is used to protect components such as IGBTs, thyristors or other power semiconductors, the fuse needs to respond to a fault in a way that matches the characteristics of the equipment.
This is why a semiconductor fuse should not be selected simply because its current rating is the same as the original fuse.
Chifeng's 580M semiconductor square fuse series is designed according to GB/T 13539 and IEC 60269-4.
For example, the 580M 64259 is rated at 690V and 1600A, with a 100kA breaking capacity. The fuse is classified as aR and is intended for applications such as power conversion systems, battery energy storage systems and DC common bus systems.
Those specifications need to be considered together. The standard tells you about the requirements the product is designed to meet; the electrical ratings tell you whether that particular model is suitable for the system.
Why does UL matter for some projects?
For equipment going to North America, UL may be part of the customer's purchasing requirements.
This is where buyers sometimes make a simple mistake.
A supplier may have UL-approved products, but the particular fuse you are asking for may belong to a different series.
The easiest way to avoid confusion is to ask for the certificate covering the actual model.
The model number, rated voltage, rated current and applicable standard should correspond with the product on the quotation and datasheet.
This becomes particularly important when replacing a fuse from another manufacturer. A replacement may have the same current rating but still have different dimensions, electrical characteristics or certification requirements.
CE, TÜV, CB and CCC are not interchangeable
It is also common to see several certification marks listed together on a supplier's website.
They should not simply be treated as different versions of the same certificate.
CE relates to conformity with applicable European Union requirements.
TÜV certification provides third-party assessment for applicable products and standards.
CB certification is based on the international IECEE CB Scheme and can be useful when products are supplied into different international markets.
CCC is China's compulsory certification system for products covered by the relevant regulations.
Whether a particular certificate is needed depends on the product, destination market and end equipment.
For this reason, a buyer in Germany may have different requirements from a buyer purchasing the same fuse for equipment sold in China or the United States.
Chifeng's applicable product certifications include TÜV, CE, CB and CCC, depending on the product series and requirements.
ISO 9001 is important, but it is not a product certificate
This distinction is worth making because ISO 9001 is often mentioned alongside product certifications.
ISO 9001 concerns the manufacturer's quality management system.
It tells a buyer something about how the company manages its production and quality processes. It does not, by itself, prove that a particular semiconductor fuse has passed all the tests required for a specific product standard.
For a fuse manufacturer, both sides matter.
You want to know that the factory has a controlled quality system, but you also need to know that the fuse itself meets the relevant technical requirements.
What does the certificate actually cover?
This is probably the most useful question a buyer can ask.
Suppose a manufacturer says:
"Our products are TÜV certified."
That sounds reassuring, but it leaves several things unanswered.
Which product?
Which series?
Which rated voltage?
Which current range?
Which standard?
Which certificate number?
The same applies to UL, CB and other product approvals.
A certificate should be checked against the actual fuse being purchased. This is especially important when a supplier has a large catalog covering different types of fuses.
At Chifeng, different product series are developed for different applications, so certification and technical information are provided according to the relevant product.
Why is breaking capacity part of the discussion?
Certification should not be separated from the electrical performance of the fuse.
Consider a 1600A semiconductor fuse.
The number 1600A tells you the rated current, but it does not tell you how the fuse will behave when a serious short circuit occurs.
Breaking capacity is another important part of the specification.
The Chifeng 580M 64259, for example, has a 100kA rated breaking capacity under its specified conditions.
For equipment such as power converters and energy storage systems, where fault currents can be high, this is not a specification that should be ignored when comparing suppliers.
What about aR and gR?
The fuse class also deserves attention.
You may see designations such as aR and gR when looking at semiconductor fuses.
These classifications describe different protection characteristics and application requirements.
An aR fuse is intended for short-circuit protection of semiconductor devices. That makes it different from simply choosing a general-purpose fuse with the same voltage and current rating.
If you are replacing an existing fuse, check the class together with the voltage, current, breaking capacity, I²t characteristics and physical dimensions.
A replacement should match the requirements of the equipment, not just the number printed on the old fuse.
What documents should you request?
A serious supplier should be able to provide more than a product photograph and a price.
Depending on the project, buyers may need:
Product certificates
Test reports
Technical datasheets
Product drawings
Time-current characteristics
I²t data
Breaking capacity information
Installation information
Quality management certification
Not every project needs every document.
The important thing is that the manufacturer can explain what documentation applies to the fuse you are buying.
Certification does not replace manufacturing capability
A certificate tells you that a product or system has met certain requirements.
It does not tell you everything about how the product will be made over the next several years.
For industrial buyers, production consistency matters as well.
The fuse element, ceramic body, filling material, terminals and assembly process all have an influence on the final product. If these processes are not well controlled, two batches with the same model number can still show unwanted differences.
This is one reason it is useful to look at the factory as well as the certificate.
Chifeng has been manufacturing fuses since 1988. Its production covers high-speed fuses, semiconductor fuses, photovoltaic fuses, energy storage fuses and other circuit protection products.
The factory has production and testing facilities covering processes such as fusible element production, precision component processing, assembly and quality inspection.
For a customer, this means certification is only one part of the supplier evaluation.
What should you check before placing an order?
Before approving a semiconductor fuse supplier, it is worth putting a few simple questions to them:
Which standard applies to this model?
Does the certificate cover this exact model?
What are the rated voltage, current and breaking capacity?
Is the fuse aR or gR?
Can you provide the I²t and time-current data?
Can you provide the product drawing and test report?
Where is the fuse manufactured?
Can you supply samples for evaluation?
These questions usually reveal quite quickly whether you are talking to a manufacturer that understands the product or simply a supplier quoting from a catalog.
The right certification depends on the application
There is no single certificate that makes a semiconductor fuse suitable for every project.
A fuse used in industrial equipment may have different requirements from one installed in a solar inverter or an energy storage system. The destination market can also change the documentation required by the customer.
So certification should be looked at together with the actual application.
For us at Chifeng, the starting point is always the fuse itself and the equipment it is going into.
If you are comparing semiconductor fuse suppliers, send us the voltage, current, application, existing fuse model and target market.
We can then check the appropriate fuse series, technical requirements and available certification for your project.