DC Under- or Over-Voltage Relays TTB7000
The TTB7000 series forms a complete range of instantaneous DC overvoltage or undervoltage relays:
DC overvoltage (ANSI 59DC)
TTB7011
DC undervoltage (ANSI 27DC)
TTB7013
DC over- and under-voltage, used for loss of excitation in synchronous machines (ANSI 59DC, 27DC)
TTB7025
DC undervoltage with two pickups (ANSI 27DC)
TTB7026

TTB7027 (overvoltage with two pickups) is no longer available.

See the homepage for Static relays for the full brochure.