Question:       

How do I install a “TR” Twisted-Pair system?

Answer:

IMPORTANT NOTE: This document refers to the ‘TR’ (TRANSLATOR-DRIVEN) twisted-pair system, not the newer rs-485 system.  If you have an rs-485 twisted-pair system, get the correct documentation for that system.

The “TR” system is one of several installation options offered by Q-COM Corporation.  It has quite a few unique features and advantages over other options, but does require that a cable with a pair of twisted wires be run to every unit.  In other words, a small cable (similar to a speaker wire) connects all of the Q-COM units (sensors, commanders and translator) together for communications purposes.

The installation is easy if you have the following items:

·         A TR Translator Unit (modified from a standard unit to a TR unit)

·         All TR Sensor motherboards and Device Commander motherboards (also modified from standard to TR units)

·         Sufficient quantity of twisted pair cable to physically connect ALL Q-COM units together

·         This cable should have a PVC jacket; be shielded; have a pair of 22 gauge (minimum) stranded, twisted wires inside the jacket and shield.

The TR units can be connected in any arrangement that is convenient, as long as the wire color-code is maintained and every unit is attached to the twisted pair at some point.  You can use a ‘daisy-chain’ or a ‘star’ connection layout as shown below.

 

WIRING THE TRANSLATOR UNIT
Turn off the power to the translator unit.  Remove any power wires from the H2 or H3 lugs on the J1 plug (the two left-hand lugs) and cap them with a wire-nut (or remove them) so they cannot short circuit.  Do the same with the GREEN wire on the ‘E’ lug of J1.  This should leave just a 120-volt AC hot wire on Lug H1 (usually black) and a neutral wire on Lug ‘N’ (usually white) on the J1 plug.  Next, connect the WHITE wire of the twisted-pair to lug H3 of the J1 connector, and the BLACK wire to the ‘E’ lug of J1.  Plug J2 into the motherboard.  Route this twisted-pair cable to every other Q-COM unit in the system that will use TR communications.

WIRING THE SENSOR & COMMANDER UNITS
Turn off the power to the unit.  Take the twisted-pair cable from the previous unit and the cable to the next unit (if there is one), strip back the outer jackets and wrap the two black wires together.  Now crimp a push-on connector onto the two black wires.  Do the same with the white wires.  Install the BLACK wire of the twisted-pair to TB3 Lug ‘G’ (if there is a wire there already, use a splitter [available at most auto parts stores] to allow two wires on the same lug), and the WHITE wire to TB4 Lug-1.  If this is the last unit on a run of cable, install a 100-ohm terminating resistor between the white and black wires by crimping it into the connector along with the wire.

WIRING VENT RELAY UNITS (VR-101s)
Make up the twisted-pair wires as described above, then plug the WHITE wire on TB3 Lug-7 and the BLACK wire on TB-3 Lug-1.

TERMINATION RESISTORS
At the end of any leg of the TR cable add a 100-ohm load resistor across the white and black wires of the TR cable as shown in the diagrams, which follow.

The specially modified TR Units are connected a follows:

If you need further information contact Customer Service at (800) 720-7577.