SHANDONG ZIBO INSULATORS CO.,LTD.
Telephone:+86 533 6028207 Facsimile: +86 533 6028200 Zip Code:255129
Address： Zichuan District, Zibo City, Shandong Province, P.R,China
Operation and Maintenance Manual
1. File
The operating unit shall establish insulator files in accordance with the
regulations.
2 Inspection
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When patrolling and inspecting insulators, if it is found that the locking pin is
missing or the insulation part is damaged, it should be reinstalled or replaced
in time, and the insulators should be inspected according to the following
provisions.
a)
Check the metal accessories of insulators.
b)
Cracks and damages of porcelain parts, traces of partial discharge of
insulation parts, adhesive cement and locking pin.
c)
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Steel foot corrosion inspection.
The insulator can be judged to have failed if one of the following conditions
occurs.
a) Cracks and yellow rust spots on the iron cap (acid return).
b) Bending and cracking of steel feet.
c) Serious arc burning of iron cap and steel foot.
d) The iron cap, insulation parts and steel feet are not on the same axis.
e) Cracks and damage of porcelain parts.
f) Serious arcs burn on porcelain enamel.
g) Crack or skew of cementing cement at steel foot h) corrosion of steel
foot.
h) Corrosion of steel foot.
3. Detection
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Content detected
The main contents of porcelain insulator inspection include porcelain cracks and
damage, self-explosion, steel foot and iron cap rust, steel foot bending, etc. Test
methods, requirements and criteria
The operating unit shall, in accordance with the requirements of DL/T741,
conduct a general test within 3 years after the insulator is put into operation, and
the test cycle can be extended according to the measured degradation rate and
operating experience, but the longest shall not exceed 10 years. Its detection
methods, requirements, criteria and detection cycle are as follows:
Test methods, requirements and criteria for insulators
a. Measure voltage distribution (or spark gap)" - Normal operation
1) The voltage value of the tested insulator is lower than 50% of the standard
specified value, the insulator is judged to be deteriorated.
2) If the voltage value of the tested insulator is higher than the standard value
of 50% and significantly lower than the electric value of qualified insulators on
the adjacent sides, the insulator will be judged as deteriorated.
3) If the insulator fails to discharge under the specified spark gap distance
and discharge voltage, it is judged to be deteriorated.
b. Measurement of insulation resistance - power failure or live
1) Voltage class 500kV and above: insulator insulation resistance is less than
500 MΩ, judged as deteriorated insulator.
2) The voltage class is below 500kV: the insulation resistance of the insulator
is lower than 300 MΩ, and the insulator is judged as deteriorated.
c. Power frequency withstands voltage test - power failure
Apply 60kV dry frequency withstand voltage for 1min to porcelain
insulators with rated
mechanical and electrical failure
load of
160kN~530kN; Apply the dry-working strobe voltage value corresponding
to the normal type of insulator to the large-diameter anti-pollution insulator.
Those who are not tolerated are judged to be deteriorated insulators.
d. Appearance inspection - normal operation
Enamel defect area does not meet the requirements of GB/T772, and the
failure insulator judged in 10.2 is judged as deteriorated insulator
e. Mechanical failure load test - power failure
When the mechanical failure load is lower than 100% of the rated
mechanical load, the insulator will be judged as deteriorated
Note 1: For the third and fifth test items, those with test conditions are not required to be
tested, while those without test conditions are required to be tested periodically.
Note 2: The third test is the negotiation project between the supply and demand parties.
If in doubt, further testing is required.
Porcelain insulator testing cycle
The annual low (zero) value rate % <0.005, 5 to 6 years, >0.005 to 0.01, 4 to 5
years, >0.01, 3 years.
Note 1: When the average annual low (zero) value rate of the tested porcelain
insulators is less than 0.001% at year 7 or 8, the testing cycle can be extended
to 10 years.
Note 2: Mechanical strength test is conducted every 5 years.
Note 3: Substation insulator reference is performed.