Product Information

The Summarize Measurement and Protection Unit (SMPR-1) has been designed to measure the line and ground RMS currents and supply RMS voltages under normal conditions or under disturbances. The voltage and current signals are sensed throughout potential transformers (PT) and current transformers (CT) from each line. This information is internally processed by the microprocessor, to take the current protection actions defined under ANSI, IAC or IEC standard. Additionally the operational conditions of the breaker or disconnector are also signalized. The different functions provided by the SMPR-1 may be classified into the following groups:

• Primary and backup protection for power plants, utility and industrial distribution systems.
• Protection of transformers, overhead lines, cables and generators.
• Permits the opening of the switch/disconnector within the limits of its capacity, those identifying the excess (e.g. straight short-circuits), leaving the circuit interruption to the back-up fuses.

• CT primary ratio selectable in 5 amp steps (10 A to 5000 A).
• Inverse time phase overcurrent (ANSI 51) and inverse time ground overcurrent (ANSI 51N/51G), with selection of curves according to ANSI, IAC or IEC/BS142, as follows:

Moderately inverse.
Standard inverse.
Very inverse.
Extremely inverse.
Definite time.

• Instantaneous overcurrent (ANSI 50).
• Instantaneous ground overcurrent (ANSI 50N/50G).
• Overload alarm adjustment to one level.
• Overvoltage (ANSI 59).
• Undervoltage or minimum voltage (ANSI 27).
• Underfrequency and Overfrequency (ANSI 81).
• Power factor (ANSI 55).
• On request: Homopolar overvoltage (ANSI 59N).
• On request: Directional phase/ground overcurrent (ANSI 67/67N).
• On request: Automatic reclose (ANSI 79).
• On request: Thermal image (ANSI 49).
• On request: Negative sequence current (ANSI 46).
• Accumulated KA per phase on breaker interruption.
• 1 trip relay and 1 alarm relay.
• 1 breaker close relay
• Loss of control volts relay.
• 4 contact inputs from external devices (breaker status, breaker earthed, external reset and input 1 ).

• RMS line and ground currents.
• Maximum instantaneous line and ground currents.
• RMS line or phase voltages.
• Active power (KW), reactive power (KVAR) and apparent power (KVA).
• Active energy (MWhr) and reactive energy (MVARhr).
• Power factor and system frequency.
• Positive and negative real power (KW) and reactive power (KVAR).
• Running and maximum demand: current per phase (A), real power (KW), reactive power (KVAR) and apparent power (KVA).

• LED and LCD display indication.
• Touchpad programming.
• Indication and storage of fault conditions and their values.
• Indication of the breaker or disconnector position (open, close, earthed).

• Remote digital communication to a PC or PLC, via RS422 or RS485.
• Remote adjustment of protection and relay characteristics.
• Storage of faults and events for further statistical treatment.
• Capable of remote opening or closing of the breaker or switch/disconnector.