Chapter 7 Rules for measuring work with portable i

Chapter VII provisions on the use of portable instruments and meters for measurement

section I provisions on nuclear phase work

Article 248 group work ticket shall be filled in when nuclear phase pole and voltage transformer are used for nuclear phase work. This work shall be carried out by at least three people. The guardian shall be present and keep constant supervision

the nuclear phase rod used in article 249 should be checked and wiped before use, and its outside should be free of cracks and pencil marks. When using, the resistance and insulation resistance of the nuclear phase rod should be measured with a high-voltage (2500 V) megger. It is forbidden to change the nuclear phase pole with different voltage levels

article 250 operators should wear insulating boots, insulating gloves, long sleeved overalls and goggles. During measurement, the supervisor shall give unified command, the signal shall be clear, and the operator shall repeat it before operation

when measuring in article 251, the instrument used should have enough insulating support to the ground, and its connection should be wrapped neatly with a wire wheel, and it should be pulled slowly, and pay attention to the safe distance from the surrounding

article 252 when this work is carried out outdoors, the work shall be stopped in case of strong wind, rain and fog

Article 253 the newly packed plastic film and cover opening are polymerized from sugarcane extract, and the surrounding of the nuclear phase section should be surrounded by red ropes or temporary barriers to prevent others from approaching or entering by mistake

article 254 the use of voltage transformers for nuclear phase work shall comply with the following provisions in addition to the above relevant provisions:

first, the magnetic insulation of voltage transformers shall be free of cracks, and its sheath and secondary shall be reliably grounded

II. The voltage transformer should be placed on a stable stand or insulating pad at a high place

III. the connecting wire should be shortened as far as possible when it meets the conditions of use, and its insulating rod head should have a hook that can be pressed by the screw thread

article 255 when doing low-voltage nuclear phase work, it should be carried out by at least two people. It is forbidden to hold a voltmeter, and the safety distance specified in Table 1 should be maintained with the live part

section II provisions on the use of voltage transformers or current transformers for measurement

article 256 when using voltage transformers, current transformers and meters for measurement on high-voltage circuits, at least two people should carry out the measurement and fill in the team work ticket

article 257 current transformers, ammeters and other measuring instruments are wired and disassembled. When it is necessary to disconnect the high-voltage circuit, all the equipment and instruments connected to this circuit should be powered off, including a streamline equipment equipped with a customized mixing head from henegie and a hybrid metering equipment from Klaus mafi. The cross section of the conductor connecting the current circuit shall meet the requirements of the measured current value

article 258 voltage transformers, voltmeters and other high-voltage measuring instruments can be wired and disassembled. They can work live without disconnecting the high-voltage circuit. However, the conductor shall not have joints, and the length of the conductor shall be shortened, otherwise it shall be fixed with insulating support

article 259 when using voltage transformer for measurement, all wiring on the low-voltage side should be connected first, and then use insulating tools to connect the voltage transformer to the high-voltage measurement at one time. There should be someone to supervise the work. The operator should wear insulating gloves and goggles and stand on the insulating pad. Outdoor 8.1 the ex factory products should have product certificates, which include: insulating boots (shoes) should be worn during operation

Article 260 the shell of instruments and meters is non-metallic and should be insulated from the ground. If it is metallic, it should be reliably grounded

article 261 the measuring instruments shall be placed so that the distance between the meter reader and the high-voltage live part is not less than the safety distance specified in Table 1

article 262 all measuring devices should be surrounded by barriers or red ropes, and hang "stop! High voltage danger!" Signboard of

section III provisions on the use of tuning fork and clamp ammeters for measurement

Article 263 the attendant shall have a guardian for the measurement work of using tuning fork ammeters on the high-voltage circuit

it is forbidden to use wires to measure from the clamp ammeter to another meter

article 264 when using a tuning fork ammeter to measure high-voltage current, you should wear insulating gloves. When measuring low-voltage, you can wear wire gloves and stand on an insulating pad

article 265 when measuring the current of each phase of the high-voltage cable, the distance between the lines of the cable head lead should be more than 300 mm, and it can be carried out only when the insulation is good and the operation is convenient. When one phase is grounded, it is strictly prohibited to measure

Article 266 when using a clamp on ammeter, pay attention to whether the range of the clamp on ammeter meets the requirements of the measured current. When measuring bare conductors, special attention should be paid to the distance to ground and the distance between wires to prevent grounding and short circuit. During the measurement, it is forbidden to change the measuring range

article 267 clamp on ammeters should be kept in a dry room and wiped clean before use

Section IV provisions on using insulator megger for measurement

Article 268 for measuring insulation resistance, megger with appropriate voltage shall be selected according to the voltage level of the equipment. The tested equipment shall be powered off

Article 269 when carrying out measurement work on high-voltage equipment, two people should carry out it and fill in the team work ticket

article 270 before measuring, it should be ensured that there are no workers on the equipment. No one is allowed to approach the tested equipment during measurement. Especially when measuring cables and long-distance lines, the staff at the other end must be informed in advance

Article 271 when measuring on any circuit of double circuit high voltage line on the same pole, in order to prevent induced voltage, the other circuit must be powered off at the same time

if there is a parallel section between a single circuit and another live high-voltage line, the other circuit should also be powered off

Article 272 in case of lightning, insulation resistance measurement shall not be carried out on the road

article 273 when measuring the insulation resistance of cable lines or capacitors and long-distance overhead lines, discharge should be carried out first. Before stopping the shake measurement, disconnect the lead of the megger from the tested equipment first, and then stop the rotation of the megger to prevent damage to the megger

article 274 when telemetering the insulation resistance near the live equipment, the location of the megger must be appropriate. The telemetering personnel should not only maintain a safe distance from the live equipment, but also have someone to monitor it

article 275 megger with grounding terminal shall be grounded in advance when working. The connecting wire used shall be well insulated

Section V provisions on the use of grounding megger for measurement

Article 276 the use of grounding megger for measurement shall comply with the relevant safety provisions of Section IV of this chapter

Article 277 when measuring the grounding resistance of "two fires and one ground" power generation, it must be carried out after the power failure in the whole March

article 278 when shaking the grounding megger, there should be no open circuit