170M Series: The Industry Standard 

The Bussmann 170M series is the most widely specified square-body fuse family for high-voltage DC applications in electric vehicles and battery energy storage systems. With ratings spanning 25A to 2000A at voltages from 700 Vac to 1000 Vdc, the 170M family offers a solution for virtually every EV and ESS protection requirement above 400 Vdc. The series uses IEC-standardized DIN 43653 dimensions (square body, blade contacts) manufactured in four physical sizes: Size 000 (25-100A, compact dimensions); Size 1 (125-400A); Size 2 (315-630A); Size 3 (500-2000A, primarily AC applications).

170M17XX -- 800 Vdc / 50 kA / tc=1 ms

The 17XX suffix denotes 800 Vdc voltage rating. This series is the workhorse for 800V EV platforms (Porsche Taycan, Hyundai E-GMP, Mercedes EQS) and 800V utility-scale BESS. Available ratings: 25A, 32A, 40A, 50A, 63A, 80A, 100A, 125A, 160A, 200A, 250A, 315A, 350A, 400A, 450A, 500A, 630A. Specifications: 800 Vdc (also rated for 700 Vac); 50 kA at tc=1 ms; Operating class aR; UL Recognized, IEC 60269-4, CE.

170M18XX -- 1000 Vdc / 50 kA / tc=1 ms

The 18XX suffix denotes 1000 Vdc voltage rating -- the highest standard voltage in the 170M catalog. Specified for 900V nominal battery systems approaching 1000V peak, 1000V utility-scale BESS, and next-generation 1000V EV platforms currently under development. Available ratings: 25A through 500A in standard catalog; larger sizes by request.

170M18XX I2t Data -- 1000 Vdc, 50 kA

Physical Dimensions and Mounting

Size 000 body dimensions: 35 mm width, 47 mm height, 51 mm depth, 40 mm blade spacing. Size 1: 40 x 48 x 79 mm body, 50 mm blade spacing. Size 2: 47 x 58 x 79 mm body, 55 mm blade spacing. Mounting uses standardized busbar contact blades compatible with IEC busbar systems. DIN rail mounting clips are available for sizes 000 and 1. Size 2 and 3 use dedicated busbar clamp hardware.

How to Read 170M Datasheets Correctly 

Five curve types are published for each 170M fuse series. Time-current curve (nominal melt): X-axis is RMS prospective current, Y-axis is virtual pre-arcing time -- use this to determine if the fuse will carry maximum operating current without opening. Total clearing curve: shows total clearing time including arcing phase, for coordination with downstream protection devices. Cut-off current curves: X-axis is prospective fault current in kA, Y-axis is peak cut-off current in kA, with multiple curves for tc=1ms, 3ms, 10ms -- essential for semiconductor coordination. I2t curves: pre-arcing and total clearing I2t as functions of fault current level, used for energy-based coordination with semiconductor device ratings. Arc voltage curves: peak arc voltage as a function of applied working voltage, to verify arc voltage stays below protected device voltage withstand ratings. Always obtain the specific Bussmann datasheet for your exact part number -- variations in I2t and time-current characteristics exist between adjacent ratings.