Motor Protection relay block 7SG17

Motor Protection relay block

Motor Protection relay block for Siemens make Reyrolle Protection Device – multi-function numerical Motor Protection relay suitable for all types of a.c. induction motors up to the highest ratings available.

Type : 7SG11 Rho3

Features and technical specifications:

1. Motor Protection
2. CT inputs : 4 No’s
3. Binary inputs : 1 No
4. Binary output’s : 4 NO & 3 C/O
5. External DC power supply required
6. RS485 Communication Port

The following functions are available

1. Thermal Overload Protection
2. Over Current Protection for phase Protection
3. Earth fault Protection
4. Phase Unbalance Protection
5. Under Current Protection
6. Number of Start Protection

This Motor Protection relay block is easily insert in your schematic diagram and connect as you like way.

Data Records

Data records are available in three forms, namely fault records, waveform records and event records. All records are stamped with time and date. The relay incorporates a clock which keeps time even when the relay is de-energised.
Time and date can be set either via the relay fascia using appropriate commands in the System Configuration Menu, or via the communications interface. In the latter case, relays connected in a communications network can be synchronised by a global command.
Alternatively, synchronising pulses can be received via a status input. To use this feature one of the status inputs must be assigned to the “Clock Sync” feature in the Status Configuration Menu. Additionally the “Clock Sync Period” setting in the System Configuration Menu should be set either to “seconds” or to “minutes” as appropriate depending on the period of the synchronising signals expected from the controlling device. If “seconds” are selected then energisation of the selected status input will result in the clock being synchronised to the nearest second with milliseconds set to zero. If “minutes” are selected then the clock is synchronised to the nearest minute with seconds and milliseconds set to zero.

Fault records

If any protection algorithm issues a trip, then the ‘Trip’ LED is illuminated and one of the following messages is displayed along with a time/date stamp:
Thermal trip, stall trip, A B C E Short Circuit Protection trip, unbalance trip. A B C Undercurrent Protection trip, temperature trip and external trip
The scrolling fault display repeats the above information in addition to:
Current in each pole IA, IB, IC, IE
Positive and negative sequence current magnitudes I1, I2
Thermal equivalent current Ieq
Phase difference current IΔ
The last ten fault records are stored in this format

Event records

The relay event recorder feature allows the time tagging of any change of state of the relay. Each event is logged with the full date and time and actual event condition every 2.5msec. The following events are logged:-
• Change of setting (though not the actual setting changes). Also indication of which group of setting is active
• Change of state of output relays, inputs status and any protection characteristic
• Trip Indication reset, test and supply failure
• Circuit breaker maintenance & failure alarms
The event storage buffer holds up to 500 records. When the event buffer is full, then any new record overwrites
the oldest.
Event records are stored in RAM with a capacitor providing back-up during breaks in auxiliary supply.