FIKE CORPORATION
FM 3020541 Fike Explosion Protection System Page 9 of 32
P/N E06-051 Rev. 8 10/06
Supervision
Note: Wire Supervision Device shall
be mounted at 1st contact device in
order to properly supervise cabling.
Device
240 ohms
End of Line
Device
820 ohms
Wire
Contact
1st
of Drain Wire
No termination
Drain Wire
P4
+
-
Shield
Twisted Pair
[ insulate ]
or
Additional Supervisory Contacts
Device
820 ohms
End of Line
Device
Series
Contact
Contact
Supervisory
Last
of Drain Wire
No termination
Twisted Pair
Device
Series
Contact
Contact
1st
Supervisory
Drain Wire
P4
+
-
Shield
2v4
2v4
[ insulate ]
2.4 volt zener diode
P4
Twisted Pair
Device
Contact
Series
2v4
Additional Supervisory Devices
Contact
Drain Wire
Shield
+
-
N/C
Super-
Contact
visory
N/C
1st
Last
820 ohms
End of Line
Device
No termination
of Shield Wire
[ insulate ]
2.4 volt zener diode
Super-
visory
4.6.2 Supervisory Circuit (P4)
The fourth input is for supervisory contact
devices (P4-1). This input circuit will not
discharge the protection system, but provides
notification of system trouble. The supervisory
input is designed to provide annunciation when
a physical condition exists that would affect the
protection system’s ability to properly respond to
a deflagration. Typical uses for this circuit could
be a low-pressure switch on a suppressant
container. The input contact can be NO or NC
type contact, programmable by the configuration
setting. The preferred “fail-safe” method is to
utilize the NC contact. Instrument cabling or
minimum 2 x 0.5 mm
twisted shielded pair
cable (20 AWG) with drain wire is recommended
for this circuit. Maximum resistance for this
circuit is 30 Ω.
Exhibit 4-10 Supervisory Circuit – Single Device
Exhibit 4-11 Supervisory Circuit NO – Single or Multiple Devices
(Preferred Wiring Method for NO Circuits)
Exhibit 4-12 Supervisory Circuit NC – Single or Multiple Devices
(Preferred Wiring Method for NC Circuits)
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