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ELECTRICITY DISTRIBUTION HV&LV (JOINT POLE)

HV&LV OVER HEAD JOINT LINE TENSION CALCULATION

Turkey is divided into four ice load regions in terms of low voltage. 4.zone (very few regions) extremely harsh condition. Calculations are given separately for the four ice loads given here. HV&LV Common Pole Selection.
Outside Diameter    d: 5,88 mm
Cross-Section S: 21,14 mm2
Conductor Unit Weighteight    P0: 0,0578 kg/m
Rated Tensile Strength     Tk: 403 kg
Initial Modulus of Elasticity  Ei: 5343 kg/mm2
Final Modulus of Elasticity Es: 6220 kg/mm2
Coefficient of Thermal Expansion  β: 0,000023 (1/°C)
Maximum Tension   σm: 7 kg/mm2 (Galvanized steel pole 1.Zone  7)
 Total Maximum Tension  Tm: 147,98 kg (Galvanized steel pole 1.Zone: 147,98)
Ice Zone Load  1.Zone 2.Zone 3.Zone 4.Zone -
% 100 Ice  Load    (Pb = k√d) - 0,485 kg/m 0,7275 kg/m 1,2124 kg/m -
% 100 Ice  Load + Weight (P1=P0+Pb) - 0,5428 0,7853 1,2702 -
% 200 Ice Zone Load  (2.Pb = 2.k√d) - 0,97 1,455 2,4248 -
% 200 Ice  Load + Weight (Pn=P0+2.Pb) - 1,0278 1,5128 2,4826 -
Average Span Length   (aort) 50 m 50 m 50 m 50 m -
 Critical Span Length   (akr) 43,37 m 20,37 m 19,85 m 13,7 m -
Maximum Temparature   (tmax) +50 °C +45 °C +40 °C +40 °C -
Minimum Temparature   (tmin) -10 °C -15 °C -25 °C -30 °C -
Critical Temparature  (tkr) 44,98 °C 38,72 °C 40,33 °C 41,7 °C -
 Maximum Design Tension  +5 °C + %100 Wind -5 °C + %100 Ice
Maximum Sag  +50 °C +45 °C +40 °C +40 °C -
 Wind Load    (Pw = c.q.f) 0,3105 kg/m
%100 Wind Load+Weight √[(%100.Pw)2 + P02] = Pn 0,3158 kg/m
%70 Wind Load+Weight
√[(%70.Pw)2 + P02] = Pn		 0,2249 kg/m
%42 Wind Load+Weight
√[(%42.Pw)2 + P02] = Pn		 0,1426 kg/m
%100 Ice and Wind Load  (Pbw) 0,6209 kg/m
 %200 Ice and Wind Load  (Pbw200) 0,7762 kg/m
√[(Pbw100)2 + (P0+Pb)2] = Pnw (kg/m) (%100 buzlu+rüzgar) - 0,8247 1,0011 1,4138 -
√[(Pbw200)2 + (P0+Pb)2] = Pnw (kg/m) (%200 buzlu+rüzgar) - 1,288 1,7003 2,6011 -

*Wind load is not taken into account in High Voltage Electricity Distribution Overhead Line calculations when the conductor wire is icy. It is obvious that wind will blow even in icy conditions. Here, with Pbw, 100% wind is applied to the conductor.
The force was calculated assuming a load. The total load on the conductor was calculated using Pnw. Especially in places where winter conditions are harsh, pole collapses are
This force must be taken into account in order to prevent it.
**Critical Temparature tkr (0C) :Since the distribution of poles on the land should be made according to the situation where the maximum sag will occur, the maximum sag is; It is necessary to calculate whether it will occur at maximum temperature or under additional load.There is a temperature that gives a sag equal to the sag in the icy state, and this temperature is called the critical temperature.

***Critical Span Length akr (m):In power distribution lines, maximum tension occurs either under additional load or at minimum ambient temperature. There is a span that separates these two situations where maximum tension occurs, and this span is called the critical span.

 

 

 
****The tension values ​​in the table below are taken from TEDAŞ publications. These values ​​are recalculated and given on the  CONDUCTOR TRACTION CALCULATIONS page. The accuracy of these values ​​can be checked from the safety distance calculations.
Ice Load Zone 1. Zone 2. Zone 3. Zone 4. Zone
Conductor Tension (Rose) : 70 100 147 148

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