VEGA Capacitive electrodes EK … with signal conditioning instrument - Manual (Page 25)

Capacitive electrodes EK with signal conditioning instrument 25
Capacitive electrode with external overvoltage protection unit
Vessel without cathodic corrosion protection
E2
E1
A2
A1 A1
A2 E2
E1
1
2
Typ
B62-36G
Typ
B62-36G
B A
Ex-area Not-Ex-area
(control room)
optionally overvoltage arrester
optionally overvoltage arrester
B62 - 36 G Ex 0 (metal housing) or
B62 - 36 G Ex (plastic housing)
(L
i
= 0,15 mH, C
i
= 1,5 nF)
Electrode EK
Outer
isolation Outer
isolation
Screen
Screen
Signal conditioning
instrument or safety
barrier
Earth/ PA-connection
terminal
to potential euqaliza-
tion line
External earth terminal
Note:
[A] Between control room and overvoltage protection system a suitable cable, if necessary a metal cover or
screen, should be used. Screen or metal cover - if necessary - must only be connected to the electrode
side of the overvoltage arrester.
[B] Between overvoltage protection system and capacitive electrode a suitable cable with metal cover, screen
or a suitable cable with metal protection tube should be used (screen, metal cover or protection tube must
be connected to the potential equalisation).
Test voltage of the cable A and B:
£ 500 V AC
min. 4 mm 2 Cu
Vessel
Zone 0
Electrical connection