Exercise 3-4

[Audio] Good Day, Engineer Nicanor B. Fabracuer! I am Paolo Martin L. Lopez and I am Leo Carl H. Nioda. For this report, we will discuss about the definitions and the specifications of the equipment used in Exercise 3-4..

[Audio] First is the Voltage Transformers, it consists of a set of six instrument-type voltage transformers installed in a half-height EMS module. Voltage transformer ratios have been carefully selected to match the power equipment with the protective devices. In the specifications, it has a voltage ratio of 208:120 volts and apparent power of 8 VA..

[Audio] Next is the Transmission Grid 'A', it consists of a transmission grid installed in a full-height EMS module. This module is used to open and close an ac power circuit under normal conditions or to interrupt this circuit under fault or abnormal situations. It can also be used for the connection of EMS motor/generator sets and loads as well as the protective relaying equipment for transmission grid protection. The Transmission Grid "A" has a voltage value of 450 Volts – 3 phases and a current of 5 amps with a coil voltage of 120 volts DC and a contact ratings of 10 amps at 600 Volts AC..

[Audio] Third equipment is the Interconnection Module, it consists of three sets of twelve 4 mm safety banana jacks and three multiple-contact connectors mounted on the front panel. This provides an efficient means of interconnecting the electrical power system (EMS system) to the relays installed in the protective relaying control station. It has a voltage rating of 450 volts and a current value 5 amps..

[Audio] Another equipment we used is the Universal Fault Module, it consists of control relays, adjustable time delay relays, contactors, a solid-state relay (SSR), current limiting resistors, and an inductor, all installed in a full-height EMS module. These components allow faults to be inserted into the electrical power system (EMS system) for training in protective relaying applications..

[Audio] The Universal Fault Module has a nominal voltage value of 208 volts and apparent power value of 100 VA. The line-to-line fault type is resistive and has a resistor ratings of 100 ohms and 500 watts. The line-to-earth fault type is also resistive and the resistor ratings are 50 ohms and 500 watts. It has a relay K1, SSR or solid-state relay, Relay TD1, Relay SST1, and a relay SST2..

[Audio] Next equipment is the Protective Relaying Control Station has two sets of dc control relays, a dc power supply, and an interconnection panel are mounted on the rack. The two sets of dc control relays (six relays per set) allow basic contacts of protective relays (either normally open or normally closed contacts) to be converted into multiple normally open (NO) / normally closed (NC) contacts to actuate ac circuit breakers (contactors) in the electrical power system. Two of the dc control relays have adjustable time delay. The dc power supply is used to energize the relay coils. Also allows connection to the Interconnect modules..

[Audio] The protective relaying station has an input voltage of 120 volts – 60 hertz and an input current of 6 amps. The output voltage is 120 volts and output current is 5 amps. It has a control relays 1 with 120 volts DC, a control relay 2 (CR1 to CR4), Control relays 2 (TD1), and an interconnection panel with a voltage value of 450 v and a current of 15 amps..

[Audio] The Three-Phase Under/Over Voltage Relay is a protective relay that is sensitive to both undervoltage and overvoltage conditions in three-phase power systems. It trips when the voltage of any one of the three phases moves outside the set voltage limits. Voltage setpoint and hysteresis adjustments are provided for undervoltage and overvoltage. Two independent sets of contacts are provided: one for undervoltage and one for overvoltage. This equipment has a nominal input voltage of 69 volts line to neutral, a maximum input voltage of 120% of nominal input voltage, an undervoltage setpoint range of 75% to 100% of nominal input voltage, an overvoltage setpoint range of 100% to 125% nominal input voltage, hysteresis range of 1% to 15% of nominal input voltage, and lastly is the output contacts of 2 x SPDTL 0.5 amps at 120 Volts DC; 5 amps at 240 Volts AC..

[Audio] The Phase Balance/Sequence Relay is sensitive to phase unbalance, phase reversal, and phase loss in three-phase power systems. It can be used to initiate an action should any one of the hazards mentioned above occur. For instance, the sensitivity to phase unbalance allows protection of a three-phase induction motor against excessive temperature rise due to unbalanced supply voltages. Unbalance setpoint and time delay adjustments as well as two sets of contacts are provided. The adjustable time delay is a useful feature which can prevent premature relay operation on short duration supply fluctuations. It has a nominal input voltage of 120 V, line to line and a maximum input voltage of 120% of nominal input voltage and a time delay range of 0.5 to 10 seconds..

[Audio] The Four-Pole Squirrel-Cage Induction Motor is a 0.2 kW squirrel-cage induction machine mounted in a full-size EMS module. The machine stator windings are independently connected (six jacks), allowing connection in either wye or delta configuration. Connections to the machine are made through color-coded safety banana jacks located on the front panel on the module. The front panel of the Four-Pole Squirrel-Cage Induction Motor module can be opened to install a Timing Belt on the pulley of the machine shaft. This permits mechanical coupling of this machine a dynamometer or prime mover. When driven by a prime mover, the Four-Pole Squirrel-Cage Induction Motor operates as a three-phase asynchronous generator. The stator voltage rating has a value of 120/208 volts, 60 hertz, and 3 phase. It has a mechanical power of 175 watts and a nominal speed of 1670 revolutions per minute and has a nominal current of 1.2 amps..

[Audio] Variable Three-Phase Power Supply (8821). It can be used to power most of the EMS modules of the Electricity and New Energy Training Equipment. This Power Supply provides dc power and ac power, both fixed and variable, single-phase and three-phase. Color-coded safety banana jacks provide access to all the power sources in the Power Supply. All these power sources can be used simultaneously, provided that the total current drawn does not exceed the maximum current rating. A built-in voltmeter with selector switch and liquid crystal display (LCD) indicates the voltage provided by any of the power sources. The input and outputs of the Power Supply are protected by independent circuit breakers..

[Audio] Here is the specifications of the Variable Three-Phase Power Supply. It has a note that the power supply cannot supply all the amounts of current indicated by the current ratings on its front panel at the same time. The current indicated for the fixed AC three-phase output section can only be obtained if no current is drawn from any other section, because this section is protected by the main circuit breaker common to every section..

[Audio] AC Ammeter (8425), The AC Ammeter module is fitted with three separate multirange ac ammeters for simultaneous measurement of three-phase currents. Two of the three meters have identical ranges while the third instrument has one additional higher range for measurement of the starting current of single-phase motors. Meter ranges and scalar values of each instrument have been carefully selected for compatibility and are appropriate for the electrical values to be measured. All meter readings are direct indications and do not require the indicated value to be mentally multiplied by a constant. All meters are diode-protected against burnout. It has an ammeter ranges of high (two meters) and low (one meter). The accuracy is 3% and the type of instrument has a value of panel meter – 65 mm of 2.5 inches..

[Audio] Lastly, the AC Voltmeter (8426), AC Voltmeter module is fitted with three separate multirange ac voltmeters for simultaneous measurement of three-phase voltages. Meter ranges and scalar values of each instrument have been carefully selected for compatibility and are appropriate for the electrical values to be measured. All meter readings are direct indications and do not require the indicated value to be mentally multiplied by a constant. All meters are diode-protected against burnout. Voltmeter ranges from low value of 0-100 volts AC and high value of 250 Volts AC with an accuracy of 2%..