Sensitive Zero-sequence Relay ITH7111
The ITH7111 is a sensitive relay for protecting electrical equipment against zero sequence (earth or ground) faults. Often used in networks with high-impedance earthed neutrals or unearthed neutrals. It has an adjustable definite time characteristic and a minimum sensitivity of 1A (primary current).

Supplied with a specific type of CEE ring transformer, of either opening or non-opening type. 
Available internal diameter is in the range of 25 to 245 mm. 
ANSI function: 64

Do you need a less sensitive earth-fault relay?  Consider the ITG7111.

A full brochure is available on the homepage for Static relays.