Vega EL 21 - Vessel with Cathodic Corrosion Protection

24 Capacitive electrodes EL 4 … 20 mA - compact
Electrical connection
A
B
2
1
E2 E1
A2 A1
2
1
A2
A1
E2 E1
Vessel with cathodic corrosion protection
(Ex)-area Zone 1
Not (Ex)-area
overvoltage protection unit mounted on oscillator
Oscillator
b)Capacitive electrodes with external overvoltage
protection unit
Screen
Cathodic tank protection 2 … 24 V (object voltage)
CB 2-36
CAP E32(H)EX
External earth terminal
Internal earth terminal
Vessel Zone 0
Li, Ci of the oscillator with overvoltage protection unit Li = 0,27 mH Ci = 8,5 nF
Control room either: Overvoltage protection insert
Signal cond. instr. or safety barrier
Type B62-36G Li=0,15 mH Ci=2,5 nF
Overvoltage protection insert
Overvoltage protection instrument in metal housing or plastic housing. The metal housing must be mounted earth free
External earth terminal
Internal earth terminal
Cathodic tank protection 2 … 24 V (object voltage)
Isolated line min. 4 mm
2
Vessel Zone 0
Oscillator Li=0,12 mH Ci=6 nF
Screen
CAP E32 (H)Ex
Type B62-36G Li=0,15 mH Ci=2,5 nF
Between control room and overvoltage protection system a suitable cable must be used, if necessary with metal cover or screen. Metal cover or screen - if necessary - must be only connected to the overvoltage protection system on the electrode side. The cable must have an outer isolation. Test voltage of the cable A: ≥ 500 V AC
Between overvoltage protection system and capacitive electrode a suitable cable with metal cover, screen or a suitable cable with metal protection tube must be used (metal cover or protection tube must not be earthed). Test voltage of the cable B: ≥ 1500 V AC
a) Capacitive electrodes with integral overvoltage
protection unit type CB 2-36
A
B