A REPLACEABLE UNIT WHICH MONITORS THE VOLTAGE OUTPUT OF THE POWER FEE D EQUIPMENT. IF THE VOLTAGE EXCEEDS A PRESET VALUE (12kV) A GAS DISCHA RGE TUBE FIRES AN ALARM AND THE EQUIPMENT IS AUTOMATICALLY SHUT DOWN. THE UNIT IS 50mm x 240mm x 230mm.

CLASSIFICATION IS DETERMINED BY THE PROVISIONS OF GENERAL INTERPRETATI VE RULES 1 AND 6 AS WELL AS THE TEXT OF HEADINGS 8535 AND 853521.