This symbol, granted by the U.S. agency, guarantees that a fuse has been manufactured in full compliance with the UL UL/CSA/ANCE (Mexico) 248-14 standard FUSES FOR SUPPLEMENTARY OVERCURRENT PROTECTION (600 Volts, Maximum) (Former UL 198G and CSA C22.2, No. 59). Some of the requirements are as follows:

• UL ampere rating tests are conducted at 100%, 135%, and 200% of rated current. The fuse must carry 110% of its ampere rating and must stabilize at a temperature that does not exceed a 75C rise at 100%. The fuse must open at 135% of rated current within one hour. It also must open at 200% of rated current within 2 minutes for 0-30 ampere ratings and 4 minutes for 35-60 ampere ratings.
• The interrupting rating of a UL Listed fuse is 10,000 amperes AC minimum at 125 volts. Fuses rated at 250 volts may be listed as interrupting 10,000 amperes at 125 volts and, at least, the minimum values shown below at 250 volts.

This symbol, granted by the Canadian agency, guarantees that a fuse or holder has been manufactured in full compliance with the CSA C22.2 No. 248.14 or CSA C22.2 No. 39 standard respectively. It's equivalent to UL Listing in the U.S.A.

This symbol, granted by the Swedish agency, guarantees that a fuse or holder has been manufactured in full compliance with the appropriate section of the IEC 60127 standard.

This symbol, granted by the German agency, guarantees that a fuse or holder has been manufactured in full compliance with the appropriate section of the IEC 60127 standard.

This symbol, granted by the British agency, guarantees that a fuse has been manufactured in full compliance with the appropriate section of the IEC 60127 (BS 4265) standard.

UL’s Component Recognition Program allows the testing of components (including fuses and holders) for which no UL standard exists or where only certain sections of a particular UL standard are referenced. A fuse or holder may be submitted to UL for testing according to criteria defined by the manufacturer. If basic safety requirements are met during testing and the component performs as predicted, it can be UL Recognized. Normally, parts bearing these marks are incorporated into equipment manufactured by an OEM and determined based on the electrical characterisrics of the product designed to provide protection for the components in the equipment. Fuses built to the European IEC 60127 fuse standard (with SEMKO, VDE, and/or BSI approvals) are technically qualified to apply for UL Recognition.

This symbol, granted by the Japan Electrical Testing Laboratory, guarantees that a fuse has been manufactured in full compliance with the Japanese MITI standard. This document is similar to UL 248-14 with subtle differences in voltage ratings and breaking capacity criteria.

The IEC organization is different from UL and CSA, since IEC only writes specifications and does not certify. UL and CSA write the specifications, are responsible for testing, and give certification. Certification to IEC specifications are given by such organizations as SEMKO (Swedish Institute of Testing and Approvals of Electrical Equipment) and BSI (British Standards Institute), as well as UL and CSA. IEC Publication 127 defines three breaking capacity levels (interrupting rating). Low breaking capacity fuses must pass a test of 35 amperes or ten times rated current, whichever is greater, while enhanced breaking capacity fuses must pass a test of 150 amperes and finally high breaking capacity fuses must pass a test of 1500 amperes.
 
60127 Part 2

Sheet I -	Type F Quick Acting, High Breaking Capacity
Sheet II -	Type F Quick Acting, Low Breaking Capacity
Sheet III -	Type T Time Lag, Low Breaking Capacity
Sheet V -	Type T Time Lag, High Breaking Capacity
Sheet VI -	Type T Time Lag, Enhanced Breaking Capacity

The letters "F" and "T" represent the time-current characteristic of the fast-acting and time delay fuses. One of these letters will be marked on the end cap of the fuse.
 
UL/CSA/ANCE (Mexico) 248-14 vs. IEC 127 FUSE OPENING TIMES (UL/CSA/ANCE (Mexico) 248-14 Was Previously UL 198G and CSA 2.2, No. 59)
 

Percent of Rating	UL & CSA std 248-14	IEC Type F Sheet 1(*)	IEC Type F Sheet 2(*)	IEC Type T Sheet 3(*)	IEC Type 5 Sheet 5(*)
110	4 Hr.
135	60 Min. Max.
150		60 Min. Min.	60 Min. Min.	60 Min. Min.	60 Min. Min.
200	2 Min. Max.
210		30 Min. Max.	30 Min. Max.	30 Min. Max.	30 Min. Max.

(*) Note: The IEC Specification is only written up to 6.3A, any components above these ratings are not recognized by the IEC (although the fuses may have those opening characteristics).
 
IEC also has requirements at 275%, 400% and 1000%; however, the chart is used to show that fuses with the same ampere rating made to different specifications are not interchangeable. According to the IEC 127 Standard, a one ampere-rated fuse can be operated at one ampere. A one ampere-rated fuse made to UL/CSA/ANCE 248-14 should not be operated at more than .75 ampere.