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Approvals & Standards

  • Mersen Self-Certification, UL Listed to Standard 248-10, File E2137
  • CSA Certified to Standard C22.2, No. 248.10 IEC 269-2-1
  • DC Tested to UL 248 limits (Mersen Self-Certified)

Key features & benefits

Amp-Trap A4BY fuses have been the industry's favorite when it comes to protecting service entrance equipment, feeder circuits, and circuit breakers. The A4BY is a 100percent rated device and may be applied at continuous currents up to its ampere rating. A 4-second minimum time delay at 500percent rating allows the A4BY to pass normal current surges and to coordinate with ground fault relays.

More specifications


  • Mains
  • Feeders
  • Circuit Breakers
  • Load centers
  • Panelboards
  • Switchboards
  • Metering Centers

Product Specifications

Item Number


Item Description (ERP)

93958-FUSE,FORM 480  

Short Description

Fuse Amp-Trap® 600V 1200A Time-Delay Class L A4BY Series TI Indicator  



Rated voltage AC UL

600   V

Rated voltage DC UL

300   V

Ampere Rating

1200   A

ROHS Compliant


Fuse Class

Class L  


Time Delay  



AC Max I.R./Breaking Capacity: I1

200   kA

Indication System


Indication System Type

TI Indicator  

Connection/Terminal Material

Silver-Plated Copper  

Connection/Terminal Type


Body/Insulating Material


Product Weight

4.5   lb

Product Diameter

2.5   in

Product Length

10.75   in

Sell Pack Quantity

1   Each

Sell Pack Weight

4.73   lb

Sell Pack Width

3.38   in

Sell Pack Length

11   in

Sell Pack Height

3.25   in