Not active product since 2007
The combined overcurrent and earth-fault relay SPAJ 321 C is used for short-circuit protection, time overcurrent protection and residual earth-fault protection for radial overhead and cable feeders in solidly earthed or low-resistance earthed networks. The relay may also be used in a variety of other applications requiring phase overcurrent protection and/or residual earth-fault protection. The relay is especially used in applications based on the use of inverse time relays, both for overcurrent protection and earth-fault protection.
Scope
- Combined overcurrent and earth-fault protection
Product benefits
- Protection for a variety of applications
Product features
- Three-phase low-set overcurrent protection with inverse time or definite time characteristic
- Three-phase, high-set, instantaneous or definite time overcurrent protection
- Non-directional residual current earth-fault protection with inverse time or definite time characteristic
- Non-directional, high-set, instantaneous or definite time, residual current earth-fault protection
- Automatic doubling of the start current setting of the high-set stage of the earth-fault unit at start-up
- Starting signals made available for the purpose of blocking cooperating protection relays
- Control input for an incoming external blocking signal
- Continuous self-supervision and auto-diagnostic fault indication to facilitate fault location and repair after detection of an internal relay fault