I. Inspection and use of insulation safety appliances
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1. What is insulation safety appliance? How many categories does it include? What are there in each category?
An insulating safety appliance is a appliance used to prevent direct electric shock to a worker.
Insulation safety appliances are divided into two categories: basic insulation safety appliances and auxiliary insulation safety appliances.
Basic insulation safety appliance: appliance whose insulation is sufficient to withstand the operating voltage. (can contact charged body)
Auxiliary insulation safety appliance: appliance whose insulation is not sufficient to withstand the operating voltage. (Do not touch charged body)
The basic insulating safety uses for high voltage equipment are: insulating rod, insulating clamp and high voltage electroscope.
The auxiliary insulation safety of high voltage equipment includes: insulation gloves, insulation boots, insulation pads, insulation tables, etc.
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2. What inspection should be done before using insulation rod, insulation gloves and insulation boots?
(1) Check whether the appearance is clean, no oil scale, no dust. No cracks, fractures, burrs, scratches, holes and obvious deformation on the surface.
(2) Insulation gloves should also be aerated test, check and confirm that there is no leakage phenomenon.
(3) There is no puncture phenomenon on the sole of the insulation boot, and the bottom pattern is clear and obvious, without signs of grinding.
(4) The connecting part of the insulating tie rod should be tightened.
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3. How to use insulation rod, insulation gloves and insulation boots correctly? How to keep it properly?
Precautions for use:
(1) Insulation gloves should be worn when using insulation tie rod. At the same time, the hand holding part should be limited to the permissible range, not beyond the protective cover or protective ring.
(2) Wear insulating boots to prevent hard sharp objects will be pricked at the bottom.
Precautions for safekeeping:
(1) Safety appliances should be stored in dry and ventilated places.
(2) Insulation rod should be suspended on the support, should not contact with the wall or oblique.
(3) Insulation gloves should be stored in a closed cabinet, and should be stored separately from other tools and instruments.
(4) Insulated boots should be placed in the cabinet, not allowed to replace the use of rain shoes, only in the operation site use.
Second, the inspection and use of maintenance safety appliances
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1. What is the maintenance of safety appliances? What kinds does it include?
Maintenance safety appliance refers to the safety appliance that should be configured during maintenance to protect personal safety and prevent stray electric spacing and prevent misoperation.
Maintenance safety equipment in addition to the basic insulation safety equipment and auxiliary insulation safety, there are temporary grounding wire, sign, safety belt, foot buckle, temporary barrier, etc.
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2. What are the requirements for the electroscope? What checks should be done before use?
(1) The electroscope must be: suitable voltage level, passed the test, the test period is effective.
(2) the electroscope should be free of dust, oil, crack, fracture and other phenomena.
(3) Before and after the electrogram, the electrogram should be tested on the live equipment to confirm that the signal is good.
(4) the connection parts of the electroscope should be firm.
(5) Insulation gloves should also be checked (according to the relevant content).
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3. Who should do the electrical inspection? What are the requirements for electrical inspection?
The electrical inspection should be done by the duty officer.
The actual operation and safety precautions are as follows:
(1) After the maintenance of electrical equipment power failure, before the suspension wiring, must use the electroscope to check whether there is voltage.
(2) Each phase of the inlet and outlet line of the construction or maintenance equipment shall be carried out separately.
(3) Insulation gloves must be worn for high-voltage electrical inspection.
(4) When repairing the circuit breaker or disconnecting switch for contact, the two sides of the circuit breaker should be inspected.
(5) The electrical inspection of the line should be carried out phase by phase.
(6) When maintenance of multi-layer power lines erected on the same rod, a priori low voltage and a posteriori high voltage; Lower a priori, upper a posteriori.
(7) The permanent signal or mark indicating disconnection of the equipment, indicating the signal allowing entry interval and the access voltmeter indicating no voltage and other no voltage signal indication, can only be used as a reference, can not be used as the basis for the equipment without power.
(8) When inspecting electricity, the electroscope should be gradually close to and contact with the charged body.
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4. What is the difference between charged body and residual charge?
Charged body: a good electroscope in the distance from the charged body about 100mm can send a signal, contact with the conductor after the signal does not weaken.
Residual charge: The residual charge can only signal when the electroscope contacts the conductor, and the signal is gradually reduced.
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5. Test cycle of safety appliance?
The test cycle of insulating rod and insulating clamp is one year;
The test cycle of insulating gloves, boots and electroscopes is six months.
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6. What are the requirements for temporary ground cables? What checks should be done before use?
(1) The temporary ground wire should use multiple strands of soft bare copper wire, the cross section is not less than 25mm2(the current market supply of temporary ground wire, a kind of colorless transparent plastic insulation in the wire, its purpose is to protect the soft copper wire is not easy to break, do not stray strands, can be regarded as bare wire).
(2) The temporary ground wire has no back flower and no dead buckle.
(3) The grounding wire and grounding rod should be firmly connected without loosening.
(4) The insulation part of the grounding rod is intact without cracks.
(5) The grounding cable clip or clip should be firmly connected with the soft copper wire without loosening.
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7. Who should hang the temporary ground wire? What are the requirements for hanging temporary ground cables?
The temporary grounding wire shall be hung by the duty officer in the case of supervision, according to the operation ticket designated place for operation. The temporary ground cable and its storage position should be numbered. The temporary ground cable should also be hung with the specified number.
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8. What are the actual operation and safety precautions for installing temporary ground cables?
(1) When installing the device, ensure that the grounding terminal is reliably grounded. When the device or line has no voltage, immediately connect the other end (conductor end) of the temporary grounding cable to the conductive part of the device or line. In this case, the device or line is grounded and short-circuited.
(2) Install temporary grounding wire must first connect the grounding end, then connect the conductor end; The order of dismantling is reversed. Use insulation rods or gloves to install or remove temporary ground cables.
(3) Temporary grounding wires should be installed for all aspects of the power outage equipment or line that may be transmitted to the power outage equipment or the induced voltage generated by the power outage equipment.
(4) Section bus in the circuit breaker or disconnecting switch, each section should be tested and grounded before maintenance. When all the step-down substations are cut off, temporary grounding wires should be installed at each possible calling side.
(5) On the indoor power distribution device, the temporary ground wire should be installed in the place without phase paint.
(6) The temporary grounding wire should be hung in the place where the working place can be seen.
(7) No circuit breaker or fuse shall be connected between the temporary ground wire and the equipment or line to be repaired.
(8) Equipment or cable lines with capacitors should be discharged before temporary grounding wires are installed.
(9) When the multi-layer power line installed with the same pole is provisioned with a temporary grounding line, low voltage should be installed first, then high voltage; First the lower layer, then the upper layer; First install "earth", then install "fire"; The order of dismantling is reversed.
(10) The installation and removal of temporary grounding wire must be carried out by two people. If the substation is on duty by one person, only the grounding wire disconnecting switch is allowed to be grounded.
(11) Where temporary ground wires are installed, a "grounded" sign must also be hung on the operating handle of the switch.
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9. How many types of labels are there? What is each?
There are four types of signs and seven types according to their nature:
(1) Prohibited: such as "Do not close the brake, someone is working!" "And" Do not close the switch, the line is occupied! .
(2) Warning: such as "Stop, high pressure danger!" "And" No climbing, high pressure danger! .
(3) Permitted categories: such as "Work here! "And" Up and down! .
(4) Reminder: such as "grounded! .
In addition, there are some signs hanging in specific places. Such as "No push-in, people working! "Electrical hazard, do not approach!" And so on.
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10. Explain the usage and number of prohibited and reminded signs? In what situations are permitted class tags used?
The prohibited type sign is hung on the "operating handle of the circuit breaker and disconnector that can transmit power to the construction equipment or construction line upon closing".
Warning signs are hung in the following places
① On a forbidden passage or door.
② The working place is near the fence of the live equipment.
③ When working on the outdoor frame, it is hung on the beam of the live equipment adjacent to the working place.
④ On the installed temporary barrier.
⑤ Near the site of the high pressure test.
Permission for class placards to be hung below
① Outdoor and indoor working places or construction equipment.
The iron frame and ladder for the staff to go up and down.
The warning label is hung on the operation handle of the grounded disconnector.
The number of hanging signs shall be specified as follows
① The number of prohibited signs should be the same as the number of working shifts.
(2) The number of reminder labels should be the same as the number of groups equipped with ground cables.
(3) The number of warning and permission signs hanging, appropriate hanging according to the scene.