Brief introduction of safety precautions when installing high-voltage control cabinet in Russia
When installing the high-voltage control cabinet in Russia, the safety specification should strictly follow the гост standard and local electrical regulations. The following are the core safety precautions from the aspects of personnel operation, equipment protection, environmental adaptation and grounding system:
A, personnel operation safety specification
Qualification and training
The installer must hold the Russian national certified electrician qualification certificate (such as свх certificate) and pass the safety training of the local power company (additional certification is required if high-voltage access is involved).
Before the operation, the Safety Plan for Electrical Installation shall be submitted, and the construction can only be started after it is approved by the owner and the supervisor.
Field operation requirements
Two or more persons shall cooperate in live working, and wear insulating equipment (insulating boots, gloves, withstand voltage ≥ 1,000 V) conforming to гост 12.4.089.
When lifting the cabinet, use a sling with a load of ≥1.5 times the weight of the cabinet (such as the breaking force of steel wire rope ≥ the weight of the cabinet ×5), and it is forbidden to carry parts exceeding 30kg by hand.
Second, the equipment to prevent electric shock protection
Protection grade and insulation design
The distance between the live parts in the cabinet and the shell shall be ≥ 25mm (гостр 50571.2.1), and the exposed copper bars shall be covered with heat shrinkable tubes (thickness ≥0.5mm), and the phases shall be separated by insulating partitions (temperature resistance ≥105℃).
When the cupboard door is opened, the exposed terminal shall be provided with a mechanical protective baffle (protection grade IP2X) made of flame-retardant ABS(UL94 V-0).
Grounding reliability
For PE wire, copper braided tape (cross-sectional area ≥ 16 mm) should be used to connect the cabinet and the grounding bar. Locking nuts (such as Shibilao nuts) should be used at the joint, and conductive paste (гост 27337) should be applied.
Three-pole method (гост 8.332) shall be used for grounding resistance test, and the grounding resistance of TN system shall be ≤4Ω and TT system ≤10Ω, and the test record shall be signed and confirmed by the supervisor.
Third, the environment and fire safety
Temperature and protective countermeasures
In severe cold areas, the cabinet should be equipped with a temperature-controlled heater (the power is configured at 1.5 kW/1m) to prevent the insulation from dropping due to condensation, and the distance between the heater and the cable should be ≥ 100mm (гост 15150).
The outdoor cabinet should be protected by IP54, and the joints should be sealed with fluororubber adhesive strips (temperature resistant-50℃~+120℃), and the top should be equipped with rain eaves (extending out of the cabinet by ≥150mm or more).
Fire prevention and explosion-proof measures
Flame-retardant cables (гост 22482, smoke density ≤50% during combustion) are used in the cabinet, and the trunking is filled with fireproof plugging material (expansion type, fire resistance limit ≥1h).
If it is installed in inflammable and explosive places (such as chemical plants), it is necessary to choose explosion-proof control cabinet (in accordance with гост 31182, explosion-proof grade Ex d IIB T4) and keep away from fire sources ≥3m.
Fourth, the electrical protection device configuration
Overload and short circuit protection
D-type trip (10~20 times the rated current) should be selected for the main circuit breaker, and the breaking capacity should be equal to or higher than the short-circuit current at the installation place (for example, 50kA breaking capacity should be selected for the 380V system), which conforms to гостр 50962.
A thermal relay should be installed in the motor circuit (action error ≤ 5%), and the setting value is 1.05 times of the rated current of the motor (гост14689).
Leakage protection and lightning protection
Residential and public places shall be equipped with residual current action protector (озн), with rated action current ≤30mA and action time ≤ 0.3s (гостр 50571.6.2).
Surge protector (SPD) shall be installed at the incoming terminal of outdoor cabinet, with nominal discharge current ≥10kA(8/20μs waveform), grounding lead length ≤0.5m, and cross-sectional area ≥ 16mm (гост 15150.29).
V. Safety Requirements for Special Scenes
High altitude area
When the altitude is more than 1000m, the electrical clearance needs to be increased by 10% every 1000m (for example, at an altitude of 2000m, the clearance will be increased from 10mm to 11mm), and the capacity of the circuit breaker will be reduced (5% every 1000 m).
Humid environment
Install an automatic dehumidifier in the cabinet (start when the humidity is more than or equal to 70%), and the drain should be led to the outside of the cabinet to avoid water accumulation; The cable inlet is sealed with waterproof glen head (IP68 grade).
VI. Acceptance and Document Compliance
Security test mandatory
Insulation resistance test: measured by a 500V megohmmeter, the insulation resistance between phases and ground is ≥ 0.5 MΩ (гост 8.302), and it needs to be discharged for more than 1 minute after the test.
Action test of protection device: the breaking time of the circuit breaker is ≤0.1s, and the leakage protector operates reliably at 1.3 times the rated action current (repeat for 3 times with an error of ≤ 10%).
Documents and identification
The cabinet should be affixed with Russian safety signs: "входпреящен" (no entry allowed) and "опас⪅".
As-built documents shall include the Safety Risk Assessment Report, specifying the risk points to be avoided during installation and the corresponding measures (such as heating scheme in low temperature environment).
Core differences and points for attention
Compared with domestic standards, Russia emphasizes heating and insulation protection in severe cold environment, and the grounding requirements of PE wires are stricter (such as prohibiting aluminum PE wires);
Certification key: all electrical components must pass EAC certification, and imported equipment must be accompanied by Russian safety instructions (translated and notarized by local certification bodies).
Following the above points can ensure that the installation conforms to Russian safety regulations, avoid electric shock, fire and other safety accidents caused by standard differences, and ensure the smooth acceptance.
