Instruction Manual

245364-V May 2002

Model 755A

d.Isolated Current Output (Optional)

1.Verify that the Current Output Board appropriate to desired output is properly in place. See Figure 2-2, page 2-3. If originally ordered with analyzer, the board is factory installed.

2.On TB2, Figure 2-1 (page 2-2), connect leads of shielded recorder cable to "MA+" and "-" terminals.

3.Connect free end of output cable to input terminals of recorder or other current actuated device, making sure that polarity is correct. If two or more current-actuated devices are to be used, they must be connected in series as shown in Figure 2-4 below

Total resistance of all output devices and associated interconnection cable must not exceed 850 ohms.

Current and voltage outputs may be utilized simultaneously, if desired.

+

+

mA -

- Recorder

755A

Analyzer+

- Controller

+

- Remote Indicator

Figure 2-4. Model 755A Connected to Drive Several Current-Activated Output Devices

e.Output Connections 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 618083 Alarm Relay Kit.

f.Alarm Output Connections

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 638254 Alarm Relay Assembly (see Figure 2-1, page 2-2).

Note the following recommendations:

1.A line fuse should be installed in the line between the (customer-supplied)

power supply and the alarm relay terminals on the Alarm Relay Assembly.

2.If the alarm contacts are connected to any device that produces radio frequency interference (RFI), it should be arc-suppressed. Rosemount Analytical Arc Suppression (PN 858728) is recommended.

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

4.Do not allow internal cable service loop to touch the detector assembly or associated inlet and outlet tubing. This precaution ensures against possible transmission of mechanical vibration through the cable to the detector, which can cause loss of accuracy.

2-4 Installation

Rosemount Analytical Inc. A Division of Emerson Process Management