The DTM7033, three-phase percentage biased differential relay, provides a particularly satisfactory solution for the protection of rotating machines against internal faults. These faults, generally caused by insulation ageing, require sensitive detection and fast clearing time in order to minimize their consequences.

The DTM 7033 meets these requirements as a result of:
» a low setting level, adjustable in steps from 2 to 14% In
» a two dual slope bias feature, the first level adjustable from 2 to 20% and second level fixed at 50%

In case of the transient response of the protected machine affects the accuracy of the current transformers to such a point that a significant false unbalance current is created, the relay's stability can be reinforced by adjusting the resistors inserted in the differential circuit.

PROTECTION   Functions

• Differential Protection [87]

Functionalities

• One low setting level, adjustable from 2 to 14% In
• Two dual slope bias feature: first level adjustable from 2 to 20%, second level fixed at 50%
• 2 output units
• Mechanical operation flag with hand reset
• Led for auxiliary voltage indication