Rosemount 755R, Инструкция по эксплуатации

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I
NSTALLATION
748213-P Rosemount Analytical June 1997 2-11
Model 755R Oxygen Analyzer
3. If at all possible, the analyzer should operate on a different AC power source, to
avoid RFI.
Alarm 1 and Alarm 2 output through the 654019 Alarm Relay Assembly is provided by
two identical single-pole, double-throw relays. These relay contacts are rated at the
following values:
5 amperes 240 VAC resistive
1 ampere 240 VAC inductive
5 amperes 120 VAC resistive
3 amperes 120 VAC inductive
5 amperes 30 VDC resistive
3 amperes 30 VDC inductive
Removal of AC power from the analyzer (such as power failure) de-energizes both
relays, placing them in alarm condition. Switching characteristics of the Alarm 1 and
Alarm 2 relays are as follows:
The Alarm 1 relay coil is de-energized when the display moves downscale through the
value that corresponds to setpoint minus deadband. This relay coil is energized when
the display moves upscale through the value that corresponds to setpoint plus
deadband.
The Alarm 2 relay coil is de-energized when the display moves upscale through the
value that corresponds to the setpoint plus deadband. This relay coil is energized
when the display moves downscale through the value that corresponds to setpoint
minus deadband.
Both the ALARM 1 and ALARM 2 functions generally incorporate automatic rest.
When the display goes beyond the pre-selected limits, the corresponding relay is
de-energized. When the display returns within the acceptable range, the relay is
turned on.
The ALARM 1 and/or ALARM 2 alarm functions may be converted to manual reset.
The conversion requires the substitution of an external pushbutton or other
momentary contact switch for the jumper that connects the RESET terminals on the
Alarm Relay Assembly. If the corresponding relay is now de-energized (i.e., in alarm
condition), the relay remains de-energized until the operator momentarily closes the
switch.
By appropriate connection to the double-throw relay contacts, it is possible to obtain
either a contact closure or a contact opening for an energized relay. Also, either a
contact closure or a contact opening may be obtained for a de-energized relay. It is