Emerson Process Management 755R manual 24

Instruction Manual

748213-S April 2002

Model 755R

e.Output Connections and Initial Setup for Dual Alarm Option

If so ordered, the analyzer is factory equipped with alarm output. Alternatively, the alarm feature is obtainable by subsequent installation of the 654019 Alarm Kit.

The alarm output provides two sets of relay contacts for actuation of alarm and/or process-control functions. Leads from the customer-supplied external alarm system connect to terminals on the 654019 Alarm Assembly (See Figure 2-5 below and Interconnect Drawing 654014).

REQUIREMENT	TYPICAL CONNECTIONS
	No. 1	NO		N
		COM		H
		NC	Alarm Bell	115 VAC
	RESET		or Lamp
Low Alarm,
Fail-Safe		NO
		COM
		NC
	RESET
	No. 2
	No. 1	NO
		COM
		NC
High Alarm,	RESET
Fail-Safe		NO		N
		COM
				H
		NC	Alarm Bell	115 VAC
	RESET		or Lamp
	No. 2
	No. 1	NO
		COM
		NC
Low Control	RESET		Solenoid
Limit,
		NO	Valve
Fail-Safe
		COM		H
		NC		N
	RESET			115 VAC
	No. 2

REQUIREMENT	TYPICAL CONNECTIONS
			Solenoid
	No. 1	NO	Valve
		COM		H
		NC		N
	RESET			115 VAC
Low Control
Limit,		NO
Fail-Safe
		COM
		NC
	RESET
	No. 2
Lower	No. 1	NO		N
		COM
Low Alarm				H
Indicator,		NC	Alarm Bell	115 VAC
Fail-Safe	RESET		or Lamp
			Solenoid
		NO	Valve
Low Control,		COM		H
		NC		N
Fail-Safe	RESET			115 VAC
	No. 2
			Solenoid
	No. 1	NO	Valve
High Control,		COM		H
Fail-Safe		NC
				N
	RESET			115 VAC
Higher		NO		N
		COM		H
High Alarm
		NC	Alarm Bell	115 VAC
Indicator,
			or Lamp
Fail-Safe	RESET
	No. 2

Figure 2-5. Relay Terminal Connections for Typical Fail-Safe Applications

Note the following recommendations:

•A fuse should be inserted into the line between the customer-supplied power supply and the alarm relay terminals on the Alarm Relay Assembly.

•If the alarm contacts are connected to any device that produces radio fre-

quency interference (RFI), it should be arc suppressed. The 858728 Arc Suppressor is recommended.

•If at all possible, the analyzer should operate on a different AC power source, to avoid RFI.

2-8 Installation Rosemount Analytical Inc. A Division of Emerson Process Management