TRB - Static Tripping Unit
Type TRB Zener Tripping Unit
Types SX, TR-1, TRB-1, TRB-2, TRB-3, TRB-4 - AUXILIARY RELAYS
TRB-1 Blocking Valve, TRB-1 Test Unit ad TRB - Static Tripping Unit
Type TRB - Zener Tripping Unit