User guide

System Hardware
Power and earth connections
If a single earth systems is used both IE and PE must be connected to
the earth.
1
2
3
4
9
10
11
12
A
A’
EAU-341
B
B’
*
31
IE
AFB earth
fault sensor
Last AFB unit
First AFB unit
EAU-341 with shielded AFB cable
1
2
3
4
9
10
11
12
A
A’
EAU-341
B
B’
*
31
IE
AFB earth
fault sensor
EAU-341 with unshielded AFB cable
Last AFB unit
First AFB unit
Connect one end of cable
shield only to earth, to avoid
closed loop of shield
*: Connect if AFB earth fault detection is required. Detection will be done towards the IE terminal (31)
If this link is unconnected, (11) must be connected to IE to reference the AFB.
AutroFieldBus connections
When shielded cable is used on the AutroFieldBus, the shielding
should be connected to the instrument earth (IE) at one end and left
floating at the other end. If earth fault monitoring on AutroFieldBus is
required, connect a wire as described in the figure. All earth fault
monitoring is done towards IE in the IFG units.
System Description, AutroSafe Integrated Fire & Gas Detection System, 116-P-ASAFE-IFG/XE Rev. B, 2005-10-27,
Autronica Fire and Security AS
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