VEGA Capacitive electrodes EK 4 … 20 mA - Compact - Manual (Page 23)

Capacitive electrodes EK 4 … 20 mA - Compact
23
22574-EN-020809
Electrical connection V
essel without cathodic corr
osion pr
otection
A
B
A2
A1
E2
E1
2
1
2
1
E2
E1
A2
A1
Overvoltage
protection unit
mounted on
oscillator
Oscillator
CB
2-36
C A P
E32(H)EX
Vessel
Zone 0
Oscillator
Li=0.12 mH
Ci=6 nF
External ground terminal
Internal ground terminal
Vessel
Zone 0
CAP
E32
(H)Ex
External ground terminal
Internal ground terminal
Li, Ci of the oscillator with overvoltage
protection unit
Li = 0.27 mH
Ci = 8.5 nF
(Ex) area Zone1 Non (Ex) area
Signal
condit-
ioning
instru-
ment
or
safety
bar-
rier
Control room
optionally:
Overvoltage
protection insert
Typ B62-36G
Li=0.15 mH
Ci=2.5 nF
Overvoltage protection insert
Typ
B62-36G
Li=0.15 mH
Ci=2.5 nF
Insulated cable
min. 4 mm
2
*
**
Screen
A
B
Overvoltage arrester type
B62-36 G in metal or plastic
housing
**
to the potential equali-
sation line
Screen
to the potential equalisa-
tion line
b)Capacitive electrodes with external
overvoltage protection unit
a) Capacitive electrodes with integrated
overvoltage protection unit type CB 2-36
A suitable cable, if necessary with metal
cover or screen, must be used between
control room and overvoltage protection
system. Metal cover or screen - if necessary
- should only be connected with one cable
end to ground or PA.
Test voltage of cable A: • 500 V AC
A suitable cable with metal cover, screen or a
suitable cable in a protective metal tube must
be used between overvoltage protection
system and capacitive electrode (metal cover
or protective tube must be connected to the
potential equalisation)
Test voltage of cable B: • 1500 V AC
* optional
Connect screen only on one
cable end to ground or PA
** optional
Connect screen only on one
cable end to ground or PA