VEGA VEGADIF 34 … 51 - Manual (Page 31)

VEGADIF 34 … 51 31
20094-EN-030731
Electrical connection
Calculation of L
int
/C
int
of the cable:
L
int
(cable) = L
ext
(ia IIC circuit) – L
int
(pressure
transmitter) – L
int
(overvoltage protection)
= 0.5 mH – 0.2 mH - 0.13 mH
= 0.17 mH
C
int
(cable) = C
ext
(ia IIC circuit) – C
int
(pressure
transmitter) – C
int
(overvoltage protection)
= 56 nF – 11.2 nF - 1 nF
= 44.8 nF
Calculation of the cable length:
0.17 mH
I = –––––––––– • m = 262 m
0.65 µH
44.8 nF
I = ––––––––––– • m = 373 m
120 pF *
To be on the safe side, the cable length in this
example should not exceed a value of 250 m.