2.5스퀘어 멀티탭 찾고 계신가요 ?

Are You Looking for a 2.5 sq Power Strip?

When you install a high-power appliance such as an induction cooktop or an air conditioner, you may hear this from the technician: “This appliance consumes a lot of electricity, so you should use a 2.5 sq cable power strip.” After hearing that, many people search online for a 2.5 square (sq) power strip, only to find that it is surprisingly difficult to locate. Even when you do find one, it is often unclear whether it is legitimate or properly certified.

With 47 years of heritage in power strip manufacturing, SUBONY explains the facts clearly.

1.5 sq vs 2.5 sq – What Is the Real Difference?

The term “square (sq)” refers to the cross-sectional area of the copper conductor inside the cable, measured in square millimeters (mm²). A thicker cable can carry more current with lower resistance, which directly relates to how much power can be used safely.

In general, a 1.5 sq cable used in households can handle approximately 10–18A, making it suitable for lighting, small appliances, and standard power strips. A 2.5 sq cable can handle around 16–25A, which is more appropriate for high-load appliances such as air conditioners, microwave ovens, and induction cooktops. A higher number simply means a thicker “hose” that can carry more electricity. Technically speaking, the technician’s explanation about cable thickness is not wrong. However, the issue begins when we move from fixed building wiring to finished consumer products like power strips.

There Is No Certification Standard for 2.5 sq Power Strips in Korea

Many customers ask, “If 2.5 sq is safer, why don’t manufacturers simply produce 2.5 sq power strips?” The answer is straightforward. Under the Electrical Appliances and Consumer Products Safety Control Act in Korea, there is no certification category for a 2.5 sq household power strip.

All power strips sold in Korea must obtain KC safety certification. The national technical standard limits household power strips to a rated current of 16A. Testing criteria are structured accordingly, and a 1.5 sq cable is sufficient for a 16A rating. There is currently no official test or approval framework for 20A or higher-rated household power strips.

If a product is marketed as a 2.5 sq power strip for household use, it is highly likely either uncertified or misleading. A product that cannot be certified under current standards cannot legally exist within the approved safety framework.

The Uncomfortable Truth About “2.5 sq” Power Strips on the Market

Occasionally, you may see online listings advertising 2.5 sq high-capacity power strips. Upon closer inspection, these usually fall into two categories.

The first type actually uses a 1.5 sq cable but markets it as 2.5 sq for promotional purposes.

The second type may install a 20A leakage breaker while still using a 1.5 sq cable and advertise it as supporting 20A or 2.5 sq capacity.

If you check the KC certification number on the Safety Korea website, you will typically find that the approved rating is 16A with a 1.5 sq cable. If the certified specification and the actual product do not match, this is clearly illegal and cannot guarantee safety.

Simply using a thicker cable does not automatically make a power strip safer. The rated current, thermal performance, and protection mechanisms must be officially tested and certified. If you encounter a product advertised as 2.5 sq, always verify its KC certification number through the official Product Safety Information Center.

Why Do Installation Technicians Recommend 2.5 sq?

Technicians in the field are not intentionally providing incorrect information. The confusion arises from mixing up in-wall building wiring with portable power strips.

Inside apartment walls, fixed wiring is often 2.5 sq or thicker, especially for high-load circuits. During construction, engineers consider heavy appliances and design the internal wiring accordingly. From an engineering perspective, it is logical to say that higher loads require thicker cables.

However, this applies to fixed internal building wiring, not to portable power strips. A properly designed high-capacity power strip rated at 16A can safely handle up to 4,000W using a 1.5 sq cable when engineered and certified correctly.

Internal Design Matters More Than Cable Thickness

Many consumers focus only on cable thickness, but the cable is merely the pathway for electricity. The more critical factor is the internal structure of the power strip itself.

Even if you use a thick 2.5 sq cable, if the internal busbar is thin, the switch is weak, or the housing is not flame-resistant, overheating and failure can still occur. True high-capacity power strips use thick copper busbars, high-performance dual-pole cutoff switches that immediately disconnect power during overload, and flame-retardant V-0 grade materials for the enclosure. The plug contact points must also be securely fixed to prevent looseness and heat buildup.

SUBONY focuses not on marketing numbers, but on designing internal power structures that safely withstand 4,000W of continuous load. Safety is not defined by exaggerated specifications. It is built through honest engineering without compromise.

We hope this explanation about the reality of 2.5 sq power strips has been helpful.

Safety always comes first. This was SUBONY.