The TTG relays of series 7000 and 7100 form a complete range of under or overvoltage relays, instantaneous or definite time (independent specified time).
The independent time relays type TTG 7134 and instantaneous relays type TTG 7034 are definite overvoltage relays which have been designed basically for supervision of the zero sequence voltage resulting from an electrical displacement of the neutral point under fault conditions.

The TTG series is supplied in a modular plug-in case type R, which may be mounted either as a separate relay, projecting or flush mounting, or as an element in a standard 19" rack cradle.