Page 305 - Offshore Electrical Engineering Manual

292 CHAPTER 2 Electrical System Earthing

(A) MAIN CONTROLROOM
TO I.S. EARTH BAR IN: TO NON I.S. EARTH BAR IN:
2
2
-SCADASYSTEM MIN 10 MM CU -SCADASYSTEM MIN 10 MM CU
2
2
-ESD SYSTEM MIN 10 MM CU -ESD SYSTEM MIN 10 MM CU
2
2
-F&G SYSTEM MIN 10 MM CU -F&G SYSTEM MIN 10 MM CU
2
2
MIN 10 MM CU
MIN 10 MM CU
-DATA ACO. SYSTEM -DATA ACO. SYSTEM
NOTE 3 NOTE 3
ISE IE
MAIN INSTRUMENT EARTH BAR MIE
NOTE 6 NOTE 3 NOTE 6
TO PLATFORM TO PLATFORM
CENTRAL EARTH CENTRAL EARTH
POINT POINT
(B) FIELD MODULE
I.S. EARTH BAR NOTE 3

JUMPER ISE NOTE 7
NON I.S. EARTH BAR NOTE 3
MODULE
MAIN
EARTH BAR
IE
JUMPER NOTE 7
PE PROTECTION
EARTH BAR

PE

FIGURE 5.2.2
(A) Typical instrument earthing (control Room). Note 3, instrument earth bars to be
2
mounted on insulators; Note 6, all main earth bars are 70 mm (B) Typical instrument
earthing (field). Note 3, instrument earth bars to be mounted on insulators; Note 6, all
main earth bars are 70 mm ; Note 7, protective earth (PE) terminals for components to be
2
connected to the main structure by distributed local earth bus. ESD, emergency shutdown;
F&G, fire and gas; IS, intrinsically safe; SCADA, supervisory control and data acquisition.