Article 398. Indoor oil-Filled transformer
Regarding the installation of indoor oil-filled transformer, if transformer is installed on location higher than second floor or lower than first floor by more than 1m, it shall be dry transformer or transformer filled with fireproof insulating substances. Installationof transformer in the compartment also shall comply with stipulations in the article 343.
It is allowed to place 2 oil-filled transformers rated up to 1,000kVA each in the same compartment if 2 machines have the same functions, common control and protection system and they are considered as 1 unit.
6 units of dry transformer or transformer filled with fireproof insulating substance are allowed to be placed in one compartment if that placement doesn’t affect over the operation and repairing conditions.
Article 399. Clearance from Indoor oil-Filled transformers
When transformer is installed indoors, theclearance between the most protruded part of transformer (at height of 1.9m to the floor) and :
a.walls and partitions - is not less than 0.3m for transformers with capacity up to 400kVA; 0.6m for transformers with higher capacity.
b.doors and protruded part of wall at entry - is not less than:
-0.6m for transformers with capacity up to 400kVA
-0.8m for transformers with capacity over 400 to 1,600kVA
-1.0m for transformers with capacity over 1,600kVA
Chapter 4-2-9 Battery Systems
Article 400. Scope of Battery Systems
As stipulated in Technical Regulation.
Article 401. Battery Systems Compartments
If using portable battery (for instance, auto battery) with total capacity not exceeding 72Ah to supply power to fixed electrical equipments, the battery can be placed together with the equipments in the same separated compartment with natural ventilation or in the general production compartment which
is out of explosionpronedanger or in metal cubiclewith ventilation system. If the above requirements are complied with, the category on dangerous explosionpronearea of the manufacture compartment is maintained unchanged.
The battery system where charging voltage of each unit is not over 2.3V can be placed in the general production compartment without explosionpronedanger, provided that ventilation sleeveshall be installed over each battery unit. In such case, the category of dangerous explosion-prone area of the manufacture compartment is maintained unchanged.
The battery system compartment shall be equipped with emergency lighting used when failure occurs.
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Article 402. Capacity of the battery system
DC power supply for communication system in power stationshall be provided from separated battery system.
In case that electrical equipment are protected by two main protective systems, the DC power supply
for |
such equipmentshall |
come |
from two separately operated busbars |
which are |
independently |
operating. |
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For |
important 220kV and |
500kV |
substation, two batterysupplies shall |
be arranged |
for regular |
operation. |
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Article 403. Charging Equipment
Regarding the charging equipment, it shall meet the following specification.
- In battery compartment shall be equipped with voltmeters with switching lock and ampere-meters in charging and sub-charging circuits of battery system.
- Sub-charging equipment shall ensure stable voltage of the busbar of the battery system within
limitation from -2% to +2%. |
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- Battery charging equipment shall equip the voltage regulator |
in order |
to control |
charging tagevol |
within the range specified by the manufacturer. |
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- Rectifier for charging and sub-charging batteries shall be |
connected |
to AC |
power supply via |
isolating transformer.
- DC busbar shall be equipped with specific device that regularly measures the insulating resistance of the poles and signalizes when nsulating resistance of each pole is decreased to 20kΩ in 220V power system, 10kΩ in 110V power system, 5kΩ in 48V power system, 3kΩ in 24V power system.
Article 404. Auto-Circuit Breakers for Battery Systems
This provision of this article shall refer to the article 299 of Volume 4.
Article 405. Battery racks and cabinets
When a battery system is installed on rack or in reliable cabinets, it shall be ensured that all elements
of battery system are reachable. And the clearance between racks, between rack and the wall, or between rack and the inner side of cabinet shall be appropriate for the operator and the maintainer to reach all cells of the battery system in consideration of the operation and the maintenance.
Battery racks shall be manufactured and tested in accordance with the requirements of the effective specification. The rack and cabinet shall be covered with sustainable layer to protect against the electrolyte and other corrosive chemical substances.
Battery cells shall be electrically insulated with supporting racks. The rack supporting to battery system with voltage level up to 48V can be installed without insulation material.
A space of at least 200mm height above the batteries shall be arranged for people to access. The clearance from the inner side of cubicle to the batteries (in case of placing battery in cubicle) shall be sufficient to avoid short circuit fault. Ventilation tube above the battery shall be able to turn around 180 degree so that the supplementary solutions can be done easily.
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Article 406. Battery bus bar & cable
Bare busbars shall be painted withtwo layers of paint resistant to corrosive chemicals. After the painting layers are dried, positive pole (+) shall be painted with red color andnegative pole (-) shall
be painted with green color. The places which are impossible to be painted shall be covered with a vaseline layer to prevent a corrosion before electrolyte is poured into a battery vessel.
The clearance between adjacent bare conductive bars shall be determined based on calculated mechanical durability. The mentioned clearance and the clearance from the busbar to other parts in the
station and grounded components shall be not less than 50mm. Busbars shall be placed on and screwed tightly to insulator.
The clearance between the supporting points of busbar (in any shape) are determined based on the calculated mechanical strength, but shall be not more than 2m. Structure, insulation, auxiliary parts, parts for fixing busbars shall have sufficient mechanical and electrical strength, and resistant to longterm impact of the electrolyte mist. Grounding of support structures is not required.
The board supporting through-wall conductive bar which is protruded out of the battery compartment shall be resistant to long-term impact of the electrolyte mist. It is not allowed touse stone or layerstructured materials for the supporting board.
The connection from output panel-board of the battery compartment to switching devices and DC distribution panel shall be done through single core cable or bare conductive bar.
During the transporting process, batteries shall be fixed and their air vents shall be closed. In addition,
the installation, operation, maintenance and safety issues shall comply with guidelines and recommendations of the manufacturers.
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