Cam switches Characteristics (p. 213) > 1 SPEED STARTER, 1 WAY - 3 PHASE MOTOR (continued) PR 17 - 20 A (AC21) 2-screw panel mount - interval: 30 mm Grey/black small handle 48 aluminium plate and frame P= 7.5 kW in 400 V 8 contacts Y ∆ 0 Cat. No. Designation PR17 9551 B4 E Q48PN SZ51BQ1 SZ51BQ1 22 48 x 50 Ø28 69 32 PR 17 - 20 A (AC21) Enclosure Cat. No. Designation Black small handle 64 aluminium plate P= 7.5 kW in 400 V 8 contacts SZ51BXQ 22 120 x 96 Ø28 101 26 177 Y 0 ∆ PR17 9551 B4 BCQ3 SZ51BXQ