The 55 mm width is standard for this current range — it'll fit alongside contactors in a motor starter lineup without overhanging the rail. Clearance requirements: 50 mm above and below, 10 mm to the side. At 400 V, you need 100 mm of clearance above the arc vent; at 690 V, 63 mm. At 240 V, no additional clearance is required above the basic 50 mm.
Breaking Capacity and Ratings
Breaking capacity is 100 kA at 240 V, 50 kA at 400 V, 10 kA at 500 V, 5 kA at 690 V. Motor horsepower ratings: 3 hp at 230 V, 7.5 hp at 200/208 V and 220/230 V, 15 hp at 460/480 V, 20 hp at 575/600 V. The 480 V rating is 20 A, 600 V also 20 A. Rated voltage range is 20 to 690 V.