On account of future rainfall due to El Niño, On Friday October 9, workers of the institution in order to perform preventive maintenance on the 15 Kv underground lines, they isolated them at the Elementary section of Colegio Americano of Guayaquil.
TECHNICAL CHARACTERISTICS OF ISOLATED CONNECTIONS OF THE UNDERGROUND 15 KV
13, 800 medium voltage lines
The line starts from 3 fuse boxes holders located on a pole that is connected to the main passing network area through primary.
This connection is three phased wire isolated # 2 15 Kv. of Fuse boxes with a capacity of: 100 Amp each.
Distribution and transformers
The underground line feeds 5 type transformers pad mounted of which 4 are monophase 50 KVA and 150 KVA three phased 1 Phased distribution is:
T-1, Phase A, 2nd basic block
– T-2, Phase A, 3rd basic block
– T-3, Phase B, Principal Office
– T-4, Phase B, 4th basic block
– T-5, Phase C, 5, 6, 7th basic block
WORK DONE
– Exterior cleaning of transformers was made.
– Weed displacement of school area
– Cleaning and adjustment of drivers and connections of high and low voltage.
– Cleaning and readjusting of ground connections.
– Cleaning tips of high-voltage input and output power.
– Megging of drivers.
INSULATION CONNECTIONS TESTS
Equipment used: 5KV Insulation Tester EXTECH 380395
Voltage applied: 5.000 Volt
Time: 1 min
Standard: 1 MΩ per KV + 1 (minimum acceptable value of 16 MΩ)
Isolation barrier. COND .: 15 KV
CONCLUSIONS
– The values obtained in the insulation resistance test drivers the connections of 15 kv are in acceptable ranges.
– It was found that the transformer T-4 has an oil leak by the handle of the low voltage breaker.
– It was found that the conductor insulation of low-voltage transformer T-4 that serves the elementary directors office has very low values, conductor X1 = 0.53 milliohms. (Minimum acceptable value 1.6 milliohms)
– Interior parts of the transformers were detected with oxidation, which were sanded and painted with anticorrosive green paint.