• Combined Reverse Power, Overload, Over Current and Short Circuit functions
• Available for 3-phase, 3-wire (2W3) or 4-wire (3W4) systems
• The Pathfinder function eases fault finding (Over Current & Short Circuit)
• Predictor early action feature
• Up to two individual very fast analogue output signals (<50mS), (optional)
• DIN96 Slave Indicator with status LEDs (optional)

Description
The digitally controlled MAG10x generator guard combines Reverse Power (R/P), Overload (O/L), Over Current (O/C) and Short Circuit protection (S/C) in one unit. Features depend on selected model.

The unit measures the voltage and current true r.m.s. value, and accuracy is independent of any wave form distortion. Less than 50mS processing time.

The standard models takes the auxiliary supply voltage from the monitored voltage (terminal 1 & 2).

It can also be delivered with optional separate AC or DC auxiliary voltage (terminal 26 & 27), but that must be specified when ordering (see page 4 for ordering code for separate Aux. Supply).

User settable trip levels and delays. Colour of LEDs indicate alarm status. Alarm LEDs flash during count-down.

Start of monitoring function is delayed when power is switched on (default 2 secs delay). In this way false tripping during power up is avoided.

The DIN-rail mounted instrument reads the power level directly in kW. The optional slave watt-meter and the triple-zone status LEDs at a glance gives the clear safety message:

• Over Current / Short Circuit
• Normal
• Reverse Power

PREDICTOR
The main feature of the Predictor function is to open bus-tie breakers or trip heavy loads to prevent a total blackout situation. The predictor relay(s) trips at set over current (O/C) or short circuit current (S/C) level, prior to the generator breaker trip. If the overload condition is still present after this load reduction the generator breaker will trip 1sec or 200mS later relative to set O/C or S/C time delays.

PATHFINDER
The Pathfinder (only on latching models) indicates the phase causing an over current or short circuit trip by the flashing pattern of the relevant LED. When either short circuit or over current trips have operated the relevant LED will flash in the following pattern to indicate the phase producing the trip.

OUTPUTS
Up to two individual very fast analogue output signals (optional) proportional to range (A or kW). This may be used as an input to a control system, to detect abnormal power conditions (loss of excitation etc). If output is used for remote meter reading, we recommend 0-1mA for the slave indicator.

RELAY OUTPUTS
A trip timer will reset if the fault is removed during count-down. Remote alarm reset input. Fixed hysteresis prevents relay "chatter". Full functionality control during power-up/power-down, with 500mS power-out reservoir. Relay operation depends on the selected model. Other combinations are available on request.