Page 24 - IZOELEKTRO catalogue 06-2020

2 SN odvodniki prenapetosti MV surge arresters

2.3 Določitev zaščitne razdalje 2.3 Determination of the shielding distance
Podatki omrežja distributerja Data of electric network
Stopnja zaščite naprav na daljnovodih je odvisna The level of protection for devices on power lines is
od razdalje med ščiteno napravo in odvodnikom. dependent on the distance between the protected device
Prenapetostni odvodnik ščiti v določeni razdalji od mesta, and the surge arrester. The surge arrester offers protection
kjer je montiran. in a certain distance from the spot where it is mounted.

Za izračun so potrebni najmanj naslednji podatki: The next data is necessary for the calculations:
• lz – zaščitna razdalja odvodnika • lz – shielding distance of the surge arrester
• Uz – zdržna udarna napetost izolacije opreme. • Uz – the allowed trigger voltage of insulating equipment.
• Ures – maksimalna vrednost preostale napetosti za • Ures – the maximum value of residual voltage for the
določen tip odvodnika chosen type of surge arresters
• v – hitrost širjenja udarnega vala po električnih • v – speed of shock wave spreading through electric
vodih power lines
v = 300 m/μs – nadzemni vod v = 300 m/μs – overhead line
v = 150 m/μs – kabel v = 150 m/μs – cable
• S – pričakovana strmina prenapetostnega udara • S – anticipated steepness of over voltage lightning
strele strike
S = 1550 kV/μs – leseni drogovi S = 1550 kV/μs – wooden poles
S = 800 kV/μs – ozemljene konzole S = 800 kV/μs – earthed brackets

Izračun Calculation
Poenostavljena formula za izračun zaščitne razdalje: Simplified formula for calculating the shielding distance:

Praviloma naj bo odvodnik prenapetosti priključen čim As a rule, the surge arrester should be mounted as near
bliže ščiteni napravi. as possible to the device it protects.

2.4 Parametri za tip 2SS15N - razred 1 2.4 Parameters for type 2SS15N - class 1

Razred odvodnika 1 Arrester class 1
Tip prenapetostnega odvodnika 2SS15N Arrester type 2SS15N
Komercialne oznake oblike R, RP, RO, NO Commercial designation R, RP, RO, NO
Trajna obratovalna napetost Uc 3 – 44 kV Continuous operating voltage Uc 3 – 44 kV
Nazivna napetost Ur 3,7 – 55 kV Rated voltage Ur 3,7 – 55 kV
Nazivni odvodni tok In (8/20µs) 10 kA Nominal discharge current In (8/20µs) 10 kA
Visok impulzni tok (4/10µs) 100 kA High impulse current (4/10µs) 100 kA
Zdržni kratkostični tok (Isc) 20 kA Short circuit current (Isc) 20 kA
Tok dolgega vala (I2ms) 250 A Long-duration current (I2ms) 250 A
Sposobnost energijske absorpcije (dolgi val) (W2ms) 2,8 kJ/kVUc Energy absorption capability (long duration) (W2ms) 2,8 kJ/kVUc
Sposobnost energijske absorpcije (impulzni tok) (W4/10) 4,8 kJ/kVUc Energy absorption capability (impulse current) (W4/10) 4,8 kJ/kVUc
Upogibni moment 24 kV (Mu) 300 Nm Cantilever strenght 24 kV (Mu) 300 Nm
Upogibni moment 36 kV (Mu) 250 Nm Cantilever strenght 36 kV (Mu) 250 Nm
Vertikalna sila (Fv) 625 N Vertical load (Fv) 625 N
Torzijski moment pri Ur= 45 kV (Mt) 80 Nm Terminal torque at Ur= 45 kV (Mt) 80 Nm

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