STM-4D Installation and Operation Manual Rev B
6
Cable Orientation and Pinouts
The use of telephone style connectors for the sensors makes it possible to use standard
telephone cables when connecting sensors to ARC Solo. However, it is important to verify the
wiring of the cables to ensure proper operation.
The designation RJ25 or RJ12 refers to a 6-pin modular telephone connector with all six pins
wired. This connector configuration is also referred to as 6P6C indicating six-position, six-
conductor.
Certain telephone cables use “crossover” wiring in which pin 1 at one end of the cable connects
to pin 6 at the far end, pin 2 connects to pin 5, and pin 3 connects to pin 4 as shown below:
Crossover Wiring
Burk’s 25’ SENSOR CABLE follows this convention. A crossover cable such as Burk’s SENSOR
CABLE must be used for the temp sensors to operate correctly.
The RJ12 Coupler supplied by Burk also has crossover wiring from one connector to the other.
Certain sensors including the TEMP-STACK, TEMP-OUTDOOR and TEMP-WALLMOUNT
come pre-wired with a cable terminated in a male RJ12 connector. These connectors may be
plugged directly into the front panel of the Climate Guard. If it becomes necessary to extend the
length of one of these cables, care must be taken not to reverse the connector wiring. Non-
reversing extension cables can be created by combining a SENSOR CABLE with an RJ12
COUPLER. Since each of these has crossover wiring, they provide a straight-through
connection from end to end when connected together.
Sensor Cable RJ12 Coupler