VEGA Capacitive electrodes EL … - Manual (Page 33)

Capacitive electrodes EL … 33
A1
A2 E2
E1 1
2 Typ
B62-36G
A
Not-Ex-area (control
room)
either overvoltage protection instrument
Outer
isolation
Screen
Signal conditioning
instrument or safety
barrier
Cathodic corrosion protection
2 … 24 V (object voltage)
Note:
[A] Between control room and overvoltage
protection system a suitable cable, if required
with screen or metal cover, should be used.
Screen or metal cover - if required - must be
only connected to the overvoltage protection
system on the electrode side. In case of
cathodic corrosion protection the cable must be
provided with an outer isolation.
Ex-area
Electrode EL
External
earth
terminal
ELB
2-36
[1]
[1] Overvoltage protection module ELB 2-36
mounted to oscillator (L
i
= 0,15 mH, C
i
= 1,5 nF)
Vessel
Zone 0
Without cathodic corrosion protection: to
potential equalization line
Electrical connection
Vessel with 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)
either overvoltage protection instrument
Metal housing
without earthing
either overvoltage protection instrument
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 EL
Outer
isolation Outer
isolation
Screen
Screen
Signal conditioning
instrument or safety
barrier
Earth / PA-terminal
Cathodic corrosion protection
2 … 24 V (object voltage)
External
earth
terminals
Note:
[A] and [B] see "Vessel without cathodic corrosion protection“ on
the previous page.
min. 4 mm 2 Cu
Vessel
Zone 0
Capacitive electrode with integral overvoltage protection module
Vessel with/without cathodic corrosion protection