c)CT, VT: 5 years

- Requirements on data for loss calculation and adjustment as well as requirements on data

validation and loss adjustment factor are not clear and need to be specified / clarified.

The Distributor may, and on the direction of the Authority shall, carry out periodic, randomand unannounced inspection and or testing of any Metering System and associated data for the purpose of ascertaining whether the Metering System complies with the requirements of this Distribution Code. The User may request the Distributor to carry out such inspection and or testing, provided that the User pays the cost, unless an error or malfunction not caused by the User is discovered. In addition, the Authority may carry out its own unannounced inspection and or test, in which case the User shall grant access to the Authority.

The Distributor shall, as soon as practicable, make the results of any inspection and or tests conducted pursuant to this Section available to the requesting party and to the User associated with the Metering System.

Article 164. Technical requirements for sealed, pair of lead and security

1. Complete energy metering system including wiring box CT,VT, power meter, clamps, connectors, circuit current, voltage, auxiliary equipment, logic switch cabinetsmeters, communication networks must be lead-sealed to prevent unauthorized intervention.

2.For electronic power meter, meter software must be password protected with different access rights.

3.The event of a power distribution unit installation and exploitation of the data collection system to measure automatically, they must meet the following requirements:

a)Measured power data after it is read and transmitted to the server located at the measurement location must be encrypted to prevent unauthorized changes;

b)Reading system management software, communications and integrated power metering data

must be secured with the multi-level password to ensure that the security, accuracy and reliability of the measurement data.

Chapter 2-6-2 Electrical Measurements

Article 165. Electrical Measurements

As stipulated in Technical Regulation.

Article 166. Requirements for Electrical Measuring Instruments

All electrical measuring instruments must meet following basic requirements:

1.Indicating or recording tools must have accuracy class of 1.0-2.5. Ammeter without number zero

(0)at the scale, installed in low voltage distribution substation, supplying electricity to residential use and electrical motors, can have accuracy class of 4.

2.Accuracy class of shunt, auxiliary resistors, measuring transducers must not be smaller than the values given in the following table:

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3.Limit of division on scale or limit of indicating numbers must ensure measurement the whole range of values to be measured.

-Connecting current winding of measuring tool and protection device with secondary winding of current transformer supplying electricity to billing meter must comply with specifications in Article 162.

-At low voltage distribution substation without duty man, it does notallows to install electricity measuring indicating tools but a space must be arranged for connecting testinginstruments or clamp-on tester.

-Electricity measuring tools with indicator, there must be red division presenting rated value on the measurement scale.

-Electrical measuring tool with decision “zero” in the middle of the measurement scale must have written directions in two sides of division “zero”.

-Electrical measuring tool must have name plate for identifying measurement points, except it is put close to the measurement on the connection diagram.

-Apart from indicating measured values on the spot,in necessary case, the measured values need to

be recorded or put into memory space or transmitted to remote measurement location, on requirement of operation.

Article 167. Measuring Voltage in 3-Phase

- Metering voltage in 3-phase electric power networks should be carried out asusing one phasephase voltmeters follows:

At electric power network with voltage over 1000V, large earth fault current, phase voltage must be measured by one voltmeter which has switching lock.

At electric power network with voltage over 1000V, small earth fault current, voltages of 3-phase conductors must be measured.

At low voltage electric power network, only conductor voltage must be measured if there is no special requirement.

-The insulation tester must be installed in over-1000V power network with small earth fault current, up to 100V power network with isolated neutral conductor and DC electric power network with isolated middle point. Insulation tester may be indicating meter, relay-based device (sound, light signal system) or combination of the above types.

Insulation tester must meet the following requirements:

Identifying earth fault when electric power network operates separately or through stariangle connected transformer.

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Easy identifying earth faults in case the substation without duty-man.

When necessary, the sound, light signalizing system for local warning or transmission to central control is arranged.

-The insulation tester in up to over-1000V power network and in DC electric power network must be able to detect resistance value of insulation, when necessary, the sound, light signalizing system is attached and acting when insulation level is reduced to set value.

-It is not necessary to install insulation tester in simple and not important DC circuit, DCcircuits with voltage up to 48V. Periodical testing insulation of these circuits by using voltmeter must be performed.

- It is allowed to use voltmeter to periodically test insulation of each pole to earth of excitation circuit of rotating electric machines.

Voltmeter with circuit switching lock may be used for testing insulation in some points of excitation circuit.

-The single phase voltage transformer of 3-phase 5-coil voltage transformer must be used for testing insulation. The high voltage winding must be connected in star with earthed neutral.

In order to supply electricity to both insulation testing circuit and measuring circuit from one voltage transformer, there must be two secondary windings of which one connected in star, with phase voltage

of 100/√3V, used for measuring circuit and one winding connected in open triangle, with phase voltage of 100/√3V, used for insulation testing circuit.

Article 168. Measuring Points for AC & DC Currents

1.AC & DC currents for measuring electricity current must be measured at appropriate places. Circuits which need systematic testing during operation process.

Generators, high and medium voltage power line feeders and loads, important low voltage power line feeders and loads.

Primary and secondary circuits of voltage transformers with capacity of 1000kVA or more. In the circuit of arc extinguishing coil there must be space for connecting recording or potable ammeters.

2.If technology process requires, recording ampere meters must be installed.

3.DC current must be measured at:

Circuits of DC power generators and rectifiers. Battery circuits, solar PV circuits.

Excitation circuits of generators, compensators and synchronous motors.

4. Three ampere meters must be installed for: 3-phase AC electric power generators with nominal capacity of 200 kW or more, synchronized to the electric power network;

Stand alone 3-phase generators;

1)Power lines with controlled each phase

2)Power line supply electricity to electric furnace.

3)Power lines with series compensation

4)Power lines can be operated continuously in phase-lost-condition

5)500kV power lines

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6) It is permissible to install an Ammeter with switch over selector to measure 3-phase current of up to 200kW power generator.

5.When selecting ampere meters and current transformers, the emporaryt overload of motor circuit during starting must be taken into account. Current must not be saturated andampere meters must be capable to stand indicate starting currents.

6.DC ampere meters must have measurement scale at both sides or pole reversing switches if measured current may change direction.

7.AC ampere meter can be directly connected or connected through current transformerAmpere. meter can be directly connected to busbar or conductorAmpere. meter is connected through current transformer if cannot be directly connected.

8.Direct connecting ampere meter to over-1,000V AC circuit and over-500V DC circuit must ensure the following conditions:

Safety for operation, management, testing and repairing staff convenience for reading indication, compliance to existing electricity safety regulation.

Insulation of electricity carrying parts ofampere meter from the earth by insulation which withstands the corresponding voltage or voltage directly exposed on busbar section between two adjacent insulators, ensuring distance of ampere meter between phase and phase, phase and earth.

Base of ampere meter must paint red and on measurement scale there must be red mark indicating high voltage.

transformer, which have the same characteristics andratio. In both cases, the measurement scales must be ruled to match phase current of the primary side.

Ampere meter installed at DC equipment are allowed to be directly connected or through shunt.

Article 169. Measuring Points for Voltage

Voltage must be measured at appropriate points:

1) Each section of AC or DC busbars at all voltage levels if this section can work separately. It is allowed to install one voltmeter with circuit switching lock in order to measure many phase positions.

6) Two sides of synchronizing Arc quenching circuit.

At test nodes of power system, voltmeter must have accuracy class of 1.0.

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Article 170. Measuring Points for Power

1)Measurement of active and reactive power for each generator. Forgenerators with capacity of 100MW or more, meters with accuracy class of 1.0 must be used.

2)Measurement of active power for each voltage transformer and power lines with voltage of 6-35kV, which supply auxiliary electricity to power plant.

Measurement of reactive power for compensating machine and compensatingcapacitor of 25MVar or more.

Measurement of active and reactive power for 2 coil step up transformer of power plants measurement of active and reactive power at low voltage and medium voltage for each step up transformer and power plant except transformers connected with generator in block diagram.

Step up 3 coil transformer and autotransformert substations, measurement of active and reactive power for each transformercapacity of 35/22-15-10-6kV or more. For other transformers, only measurement of active power is necessary.

3. It must use wattmeter andVar meter with two side measurement scales for those circuits whose power flow is various.

Article 171. Measuring Points for Frequency

1. Frequency shall be measured at:

1)Each section of busbar at generator voltage.

2)Outlet of generator of block

3)Each high-voltage busbar system of power plant.

4)Nodes which can separate the power system to the asynchronous operating parts.

2. Self-record frequency meter shall be installed.

1)At power plant with capacity of 200MW or more in power system.

2)At power plant with capacity of 6MW or more and operates independently.

3.Absolute errors of Self-record frequency meter at power plants involving in frequency modulation shall not exceed from -0.1Hz to +0.1Hz.

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