Emerson Rosemount 3490 Series, Reference Manual

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Table 3-2: Connection Terminal Descriptions (Panel-mount Control Unit)
Terminal Function Terminal marking
1 Loop supply 24V
2 Current input Iin
3 Cable screen Earth (Earth symbol)
4-6 RS232 RX-TX-0V
7-9 Current output 24V-Iout-0V
10-12 Digital input 1 and 2 IN1-IN2-0V
13-15 Relay 1 NO-COM-NC
16-18 Relay 2 NO-COM-NC
19-21 Relay 3 NO-COM-NC
22-24 Relay 4 NO-COM-NC
25-27 Relay 5 NO-COM-NC
28-29
(1)
Mains input L-N
30 I.S. Earth (Earth symbol)
31
(2)
Negative -
32
(2)
Positive +
(1) Mains-powered control unit only
(2) Direct current (dc) powered control unit only
Cabling between the Rosemount 3490 Series Control Unit (“control unit”) and a
transmitter should be a screened (shielded), twisted-pair type with the cable screen
(shield) connected to terminal 3 (marked with earth/ground symbol) on the control unit.
The cable screen (shield) should be left unconnected at the transmitter end unless there is
a terminal specifically provided for this purpose. Cable runs should be separate from any
high voltage or mains cables to avoid crosstalk or interference.
Connect terminal 30 (intrinsically safe earth/ground) to a high integrity earth/ground
point if the transmitter connected to terminals 1 and 2 is in a hazardous area. This is a
special condition for some intrinsically safe approvals.
Related information
Product certifications
3.4.3 Power connections
When the control unit is powered by mains alternating current (ac) power, select the
voltage as 115 V or 230 V using the voltage-selector slide switch.
When the control unit is direct current (dc) powered, ensure the supply is adequate (15 to
30 Vdc). Do not exceed 30 Vdc.
A switch or circuit breaker should be installed in close proximity to the instrument, and
labeled as such. Although the Rosemount 3490 Series Control Unit meets all European
Reference Manual Installation
00809-0100-4841 January 2021
Emerson.com/Rosemount 27