Gas Discharge Tubes Modified Protector 18A/18B Series Potted Gas Plasma Arresters ® Features • Conforms to BT specifications D2982B • Hermetically sealed eclosure for use in underground joints and pole tops. • Flying leads for easy connection to IDC or screw terminals. • High surge capability • Conforms to BT specification D2982B • Flame retardent materials to UL 94V0 a b e 3 ELECTRODE GDT a=TIP b=RING e=GROUND (centre electrode) 8 All dimensions in mm GAS DISCHARGE TUBES GRAPHICAL SYMBOL LITTELFUSE 3 TERMINAL POTTED ARRESTERS, 18A, 18B, CONFORMS TO BT SPECIFICATION D2982B TOTALLY NON-RADIOACTIVE, UL RECOGNIZED Electrical DC Max Alternating Impulse Impulse Discharge Discharge Current3 (A) Current4 (kA) Characteristics Sparkover1 Sparkover2 (V) (V) Insulation Max Resistance5 Capacitance6 Holdover7 (Ω) (pF) (V) 18A 210-310 800 5 5 1x108 30 100 18B 400-500 1000 5 5 1x108 30 100 (1) Measured using a rate of rise of voltage of 100V/s. (2) Measured using a rate of rise of voltage of 1KV/µsec. (3) Measured at 1 sec duration, 5 shots @ 3 min intervals, 50Hz. (4) Measured using 8/20µsec, 5 shots each polarity. ORDERING INFORMATION (5) Measured at ±170V dc (18A) or ±350V dc (18B). PROTECTOR 18A PROTECTOR 18B (6) Measured at 1 MHz, Line to ground. (7) Measured using BT test circuit. 335 w w w. l i t t e l f u s e . c o m