GE DigitalFlow GS868, Руководство для стартапов

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March 2008
1-14 Installation
Wiring an Alarms Option
Card
The Model GS868 flowmeter can accommodate up to 4 alarms option
cards. Each alarms option card includes three
Form C relays
(designated as A, B and C).
The alarm relays on the option card are available in two types:
•
general purpose
•
hermetically sealed for Class I, Division 2 hazardous areas.
The maximum electrical ratings for the relays are listed in Chapter 4,
Specifications . Each of the three alarm relays can be wired either as
Normally Open (NO) or Normally Closed (NC).
In setting up an alarm relay, it may be wired for either conventional or
fail-safe operation. In fail-safe mode, the alarm relay is constantly
energized, except when it is triggered or a power failure or other
interruption occurs. See Figure 1-6 below for the operation of a NO
alarm relay in both conventional and fail-safe mode.
Connect the two wires required for each alarm relay in accordance
with the pin number assignments shown in Figure 1-10 on page 1-20.
Figure 1-6: Conventional and Fail-Safe Operation
C
NO
NC NC
C
NO
NC NC
C
NO
C
NO
Monitoring
Alarm
Device
Monitoring
Alarm
Device
Monitoring
Alarm
Device
Monitoring
Alarm
Device
not triggered
Conventional,
not triggered
Fail-Safe,
triggered
Conventional,
triggered or power failure
Fail-Safe,