EasyManua.ls Logo

Johnson Controls T9100 - Determining Wiring and Equipment Needs; Heating Only System Wiring; Single Stage HVAC Wiring

Johnson Controls T9100
100 pages
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Loading...
75
Installation Instructions
Before you go any further, determine what your
existing wiring and equipment situation is.
A. If you have a Heating only system without Air Conditioning, the JCI
thermostat will require 3 wires: R (24Vac), C (24Vac) and W (Heat).
Most systems that only have Heating use very simple thermostats
that require 2 wires: the R (24Vac) and W (Heat). The JCI thermostat
requires 3 wires to the thermostat. In this case an Add-a-Wire
accessory will not work and it will be necessary to install another wire
for the C (24Vac) connection.
B. If you have a single stage fossil fuel heater with air conditioning,
the JCI model will require 5 wires for independent fan control. They
are R (24Vac), C (24Vac), W (Heat), Y (Cooling), and G (Fan). You
may connect only 4 wires, as instructed in the “Making 4 Wires Work
When 5 Wires Are Required” section on page 72.
If there are only 4 wires present that are connected to the existing
thermostat, there are at least 2 options available to connect the JCI
thermostat:
1. Use the 4 wires as instructed in the“Making 4 Wires Work
When 5 Wires Are Required” section on page 74, and note that
the fan will only operate with a Heating or Cooling demand.
2. Pull new thermostat wire from the HVAC equipment to the
thermostat so that there are at least 5 wires available.
C. If you have a multi-stage HVAC system comprised of a fossil fuel
heater with air conditioning, the JCI thermostat will require the 5
wires mentioned above (R, C, W, Y, G) plus an additional wire for each
additional stage of Heating or Cooling. You may reduce the 5 wire
requirement to 4 if you give up independent fan control following the
instruction in the “Making 4 Wires Work When 5 Wires Are Required
section on page 74, or use the optional Add-A-Wire accessory.

Table of Contents

Related product manuals