Fan Relay Connection
All of the SPDT Fan relay terminals are available at the Fan/Power modular connector. Each Fan relay terminal normally open,
common and normally closed (NO, COM and NC) can accommodate a wire size 12 to 24 AWG. To install the wiring for the relays,
disconnect the connector from the header. 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. Plug the modular
connection into the Fan/Power connection and ensure that it latches into the header properly.
Alarm Relay Connection
The external alarm connections (A and B) are available at the Alarm modular connector. There is no polarity for these connections. To
install the wiring for the alarm contacts disconnect the connector from the header on the detector. 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. When the wires are connected seat the modular connector into the header ensuring that the latch engages.
4-20mA Signal Connection
The positive and negative 4-20mA signal connections (+ and -) are available at the 4-20mA modular connector, a 2-position connector.
To install the wiring for the 4-20 mA contacts disconnect the connector from the header on the detector. 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. When the wires are connected seat the modular connector into the header ensuring that the latch
engages.
NOTE: The 4-20mA current loop outputs may be used with the Macurco DVP-120 control panel or other systems. The 4-20mA signal
connections to detectors should be size AWG18 (minimum) for short runs. Refer to the table for recommended wire gauges. Do not
bundle detector 4-20mA signal connections with AC power cables to prevent electrical interference. If AC power connections must be
bundled with the detector 4-20mA signal cables, the signal connections should be made with twisted pair of the appropriate gauge, with
an overall foil and braid shield. All shields should be terminated at the DVP-120 end of the cable only. A ground stud is provided near
the bottom left corner of the DVP-120 panel.
Installation
1.
The TX-12-HS mounts on a 4" square (or 4x4) electrical box supplied by the contractor. Do not mount the TX-12-HS inside
another box, unless it has good air flow through it.
2.
There are two terminals for the dry alarm relay contacts, again with no polarity preference. The alarm relay can switch up to 0.5
A 120 V, or 60 VA. The alarm relay is activated if gas reaches or exceeds the alarm settings. See OPERATION section of
these User Instructions for details on relay settings.
3.
The alarm relay can be configured to normally open (default) (N.O.) or normally closed (N.C.) and will activate if the gas
concentration exceeds alarm set point. It will deactivate once the gas concentration drops below the alarm set point. Note that
the "disable" setting will cause the alarm relay not to engage at all.
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