Relay Connections - Macurco RD-VRF Instrucciones De Usuario

•
Nominal capacity between the wires <50pF/m, nominal impedance 120 Ω. Use cable BELDEN cable
9842 or similar (data transmission cable in EIA RS485).
•
The total length of the line should not exceed 3280 ft.
•
Detectors are to be wired in daisy chain mode. We recommend avoiding star or tree mode
connection as interference immunity would be reduced.
•
Make sure that each multi-polar wire includes just one RS485.
•
Make sure that a 120 Ω end line resistor is placed at the beginning and at the end (on the last
detector) of the bus line.
•
For power supply connection, it is recommended to use a 2-wire cable with suitable section
according to the distance and number of detectors.
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Once the installation is completed, verify that each detector reaches at least 12 Vdc.
3.3.2 RD-VRF-X-120 Line Voltage Models
Except for the safety ground, all field wiring is completed via modular connectors (provided).
3.3.2.1 Power Connection
Mains connections should be done in accordance with National and Local Electrical Codes. Only qualified personnel
should connect Mains power to any device. Macurco recommends a minimum wire size of AWG18, and the wire
insulator must be rated for 140°F (60°C) service. The modular connector will accept wire from 12 to 22 AWG. The
safety ground wire should be secured to the ground screw of the metal electrical box. Tighten the screw and make
sure the wire is snug. Ensure that the wire cannot be pulled out from under the screw. The Line (L) and Neutral (N)
wires should be stripped 1/4 in. (6.5 mm), insert the wire into the "1" and "3" wire positions on the power terminal
and tighten the screw clamp. Ensure that the wire cannot be easily pulled from the connector. Refer to Figure 3-7.
3.3.2.2

Relay Connections

Both relay terminals have normally open, common, and normally closed (NO, COM and NC) connections and can
accommodate a wire size 14 to 22 AWG. To install the wiring for the relays, strip the insulation of each wire back
approximately 1/4 in. (6.5 mm), insert the bare wire into the terminal and tighten the screw clamp. Ensure that the
wire cannot easily be pulled from the connector.
3.3.2.3 Modbus Connection
When using the Modbus connection, it should be done using a RS-485, 4 conductor, 22-24AWG, shielded twisted
pair cable.
Note: Running the Modbus cable adjacent to or in the same conduit with high voltage wires is not recommended as
there may be interference from the high voltages.
•
Nominal capacity between the wires <50pF/m, nominal impedance 120 Ω. Use cable BELDEN cable
9842 or similar (data transmission cable in EIA RS485).
•
The total length of the line should not exceed 3280 ft.
•
Detectors are to be wired in daisy chain mode. We recommend avoiding star or tree mode
connection as interference immunity would be reduced.
•
Make sure that each multi-polar wire includes just one RS485.
•
Make sure that a 120 Ω end line resistor is placed at the beginning and at the end (on the last
detector) of the bus line.
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