ERL Marketing International

Sharjah, United Arab Emirates

MJT 314over current relay combines the power and flexibility of microprocessor technology with decades of experience in the field of protection. A wide range of protection elements and characteristics are supplemented by advance features such as metering, fault recorder and communication. MJT 314 offers inverse time and definite time over current protection for phase fault and earth fault with communication.

Application

• Distribution Feeders
• Transmission lines
• AC machines
• Capacitor banks
• Transformers

ARGUS 7is a combined check and system synchronising relay which can automatically select check or system synchronise from measurements of the relative phase angles between line and bus voltages. The relay will prevent closure of the circuit breaker if either the phase angle, slip frequency or the voltage magnitude of the incoming and running voltages fall outside prescribed limits.
If the parameters are within the limits the relay will issue an output which can be used to close the circuit breaker directly or in conjunction with an autoreclose scheme. Both the check and system synchronise functions have independent settings and blocking features. The relay includes split system detection with a variable time delay, which can be used for blocking purposes within delayed autoreclose schemes.
Synchronising bypass logic is provided to connect a dead line or bus to a live line or bus. For manual synchronising the relay includes a circuit breaker close guard feature which is used to prevent the control switch being held closed during a synchronising operation. This feature is implemented using internal logic and removes the need for an external relay.

Application

• Check-synchronizing
• System-synchronizing

B-PRO 4000relay provides bus and substation differential protection (low impedance) with CT saturation security, integrated breaker failure, overcurrent protection and SCADA control in a fully integrated protective relay solution. The B-PRO 4000 relay also provides control, automation, metering, monitoring, high capacity for DFR quality fault oscillography, dynamic swing recording and sequence of events logging. The B-PRO 4000 relay is suitable for simple bus applications with up to 6 feeders and 2 differential zones with breaker failure, or 4 feeders and 1 transformer, including separate full transformer differential protection.

Application

• Bus and substation differential protection (low-impedance)
• Re-configurable simple bus application up to 6 feeders and 2 differential zones
• Separate Transformer differential protection
• 6 sets of CT inputs for differential protection (18 currents) using percentage slope characteristic for security on external faults
• Low impedance design allows different CT ratios for each of the 6 inputs
• Backup overcurrent and breaker failure for each input current
• User defined directional control of overcurrent functions for networked lines
• 3 phase voltage inputs to apply over/under voltage and frequency functions
• 1 or 2 separate differential zones - bus and transformer or Bus 1 and Bus 2 for multiple buses
• ProLogic - control logic statements
• 30 virtual inputs for local or remote control applications

S-PRO 4000is a digital, microprocessor-based sub-harmonic protection system that provides comprehensive sub-harmonic protection for transmission lines at any voltage level, particularly those with serial compensation and interconnected with wind farms. Use the S-PRO Sub-Harmonic Protection Relay for monitoring and protection of uncontrolled sub-harmonics, ensuring a reliable operation of the power grid.
Undamped sub-harmonic current oscillations created by series capacitors interacting with the wind system can cause serious damage to wind turbine controllers and also to conventional generators. The wind turbine's own mechanical system interactions (tower-to-blade) can also generate sub-harmonics, which are detrimental to induction generators, transformers, and may cause resonance at the point of common coupling in the electrical grid.
The S-PRO 4000 relay detects these sub harmonic oscillations and allows the utility to monitor and protect the power system by isolating the healthy grid from sub-harmonic generation sources.

Protect against sustained sub-harmonics in wind farm operations

Undamped sub-harmonic current oscillations created by series capacitors interacting with the wind system can cause serious damage to wind turbine controllers and also to conventional generators. The wind turbine's own mechanical system interactions (tower-to-blade) can also generate sub-harmonics, which are detrimental to induction generators, transformers, and may cause resonance at the point of common coupling in the electrical grid.
The S-PRO 4000 relay detects these sub harmonic oscillations and allows the utility to monitor and protect the power system by isolating the healthy grid from sub-harmonic generation sources.

Features and Benefits

• Built on a contemporary new substation hardened hardware platform and powered by a state-of-the-art processor
• Protects the grid from sub harmonic oscillations at the point-of-common-coupling every 1 second, with additional user-configurable delays
• Provides real time processing of voltage and current signals, comprehensive sub-harmonic protection, with sub-harmonic monitoring for each frequency in the range from 5 Hz to 40 Hz
• Flexible Communications
  • State-of-the-art communications (2 rear ports, 100BASE-TX RJ-45 or 100BASE-FX 1300 nm multimode optical with ST style connector to accommodate the industrys latest network-based communications)
  • Ethernet ports with 2 unique MAC addresses that easily accommodate network access security needs
  • Front panel USB and 100BASE-TX RJ-45 Ethernet port interfaces (readily accommodate modern standard laptops)
• Reduced Cost
  • Product setting time 240 x 128 LCD graphical user interface provides convenient means to check/change specific settings and parameters
• Improved Overall Response Time
  • Expedited response to systems events (11 generic front panel LEDs can be mapped to internal elements) allowing operators to quickly identify the cause of system events

Easy to Use

• Flexible programmable logic for building customized schemes with ProLogic statements 24 control logic statements (total of 192 statements)
• User-friendly, Windows-based relay setting and record analysis software
• Enhanced DNP3.0 Level 2 SCADA communication protocol including user-selectable point lists, class support and multiple master station support
• Exceptional fault recording capabilities with 96 s/cycle, all channels with events (best combination of waveform accuracy and file size)

Application

• Sub-harmonic protection for transmission lines, particularly those with serial compensation and interconnected with wind farms
• Single and multi breaker applications

RHO 3is used for protection and management of medium and large motors and driven equipmentIt is Ideally suited for pumps, conveyors, compressors, fans etc.

ARGUS 8range of numerical voltage and frequency relays have the power and flexibility of microprocessor technology, giving a wide range of settings which are supplemented by advanced features such as metering, data storage and Fibre-Optic communications. Supervisory and self-monitoring features give added confidence to the user as well as reduced maintenance and down time. A menu-based interface gives user friendly access to relay settings, meters and operational data

Application

• Capacitor banks
• Ungrounded/ High impedance earthed systems
• AC generators
• Transmission lines
• Distribution feeders

MIB 202works on the current differential principle and takes the current inputs from both the ends of two winding power transformer and auto transformer. It provides stability against magnetic inrush conditions. Load/through fault stability is achieved through bias setting provided in the relay. It operates only for internal faults

Application

• Two winding power transformers
• Auto transformers
• Biased differential protection for generators

2TJMRelay is available in three versions viz. 2TJM 10, 11 and 12. These are disc-operated relays, and provide IDMT, single/three pole, overcurrent protection, with/without highset and with/without directional and phase fault protection. The 2TJM relays are completely drawout, and have 2NO contacts for external tripping purposes.

2TJM10:The relay comprises a die-cast frame, which carries all the sub-assemblies of induction disc, electro-magnetic system, operating coil, plug bridge and the contact assembly. Instantaneous highset and directional elements can be provided.
The electro-magnetic system comprises primary and secondary magnets arranged with four air gaps each contributing to the driving torque. The primary coil energises the primary magnet and a secondary winding which in turn energises the secondary magnet. Tappings on the primary coil permit various fault settings to be made via a plug-bridge. The plug-bridge automatically selects the highest setting when the setting-plug is withdrawn.
Two normally open contacts are provided of the bridging type, the operating arm being driven by a cam track at the hub of the induction disc. This gives considerable mechanical advantage and ensures high contact pressures, even at low operating current levels, making the contacts suitable for direct tripping.
Relay operating time is determined by the starting position of the induction disc, this is set by the time multiplier dial calibrated from 0.1 to 1.0, there is also a ^T^ mark, before the 0.1 setting, in this position the contacts are held closed, locked out. Settings are applied in ampere.

2TJM11:The type 2TJM11 relay is basically similar to the type 2TJM10, the exception being the addition of a miniature instantaneous high-set overcurrent element (type MCAA) which is fitted to the movement frame and has its operating coil connected in series with the relay primary coil. The element is of the attracted armature type and primarily designed for use with I.D.M.T.L. relays. The overcurrent setting is continuously variable by means of the calibrated cam. This element may be ^locked out^ by advancing the setting adjuster to its extremity, i.e. past the highest fault setting. The flag indicator shows on operation and is hand reset by a push fitted in the relay cover.

2TJM12:This relay comprises the I.D.M.T.L. element previously described and a directional element type ^ES^. The elements are vertically mounted on a mild steel back-plate with the directional element in the upper position; the composite relay is then housed in a 11/2 pole vertical case.
The directional element operates on the induction wattmeter principle and consists essentially of an aluminium sector mounted on a vertical spindle and arranged to rotate in the air gap between the magnetic fields derived from the line current and voltage transformers. The electro magnetic system with the three coils which provide loss of voltage compensation and hence reliable operation should the line voltage be reduced, under fault conditions, to values as low as 2% of nominal.
Under healthy system conditions or under fault conditions where the current flow is in the normal direction eddy currents induced in the sector produce a torque, the direction of which restrains relay operation. Should current reversal occur, then the direction of the torque reverses causing the moving system to rotate and thus close the contacts, the latter being so connected that they complete the I.D.M.T.L. element operating coil circuit.
The maximum torque exerted on the movement occurs when the voltage and current in the coils are in phase. However, as the system power factor may be considerably removed from unity under fault conditions, depending on both the nature of the fault and system conditions, the element can be supplied with a phase-angle introduced by fault conditions. This is achieved by employing a suitable shading ring, the requisite value of resistance and the appropriate connection.

Phase-Fault Relays:45 degree Lead Power Factor Characteristic: Relays supplied with the 45 degree lead power factor characteristic utilise the 90 degree connection, i.e.relays monitoring A-phase current are polarised by B-C voltage, thus the relay develops maximum torque with a 45 degree lagging fault current.

Earth-Fault Relays:Earth-fault relays are normally supplied with 12 and half degree lagging power factor characteristic. The current coil is connected in the residual circuit of the line current transformers and the voltage coil in the open delta tertiary winding of the line voltage transformer, the voltage coil being suitable for 190V and 63.5V on resistance and solidly earthed systems respectively.
Directional earth fault relays with a 45 lagging power factor characteristics are used in highly inductive earthing systems. The characteristic is achieved in the relay with a RC circuit in the ES element.