Manufacturer: Johnson Controls
Description: ELECTRONIC ROOM STAT ON/OFF
TCN-890x Electronic Room Thermostats
The TCN-8900 Series is a family of analog electronic
controllers designed to control heating and/or cooling
valves or dampers. The TCN-8901 has two
0 to 10 VDC proportional outputs, one for heating and
one for cooling. The TCN-8906 has two On/Off triac
outputs, one for heating and one for cooling, capable
of switching 0.5 A at 24 VAC.
The dual-scale setpoint dial enables the room
occupant to adjust the thermostat setpoint within the
range of 54 to 82°F (12 to 28°C).
Features and Benefits
❑ Small, Compact Package Provides similar look and feel to the Metastat
❑ Local Setpoint Provides easy wiring and installation
❑ Globally Scaled Unit Includes setpoint scale in both Fahrenheit and
Celsius ranges 54 to 82°F (12 to 28°C)
❑ Universal Mounting Includes wallbox and surface mounting plates
and all installation hardware
IMPORTANT: The TCN-8900 Series electronic
room thermostats are intended to control equipment
under normal operating conditions. Where failure or
malfunction of the thermostat could lead to an
abnormal operating condition that could cause
personal injury or damage to the equipment or other
property, other devices (limit or safety controls) or
systems (alarm or supervisory) intended to warn of,
or protect against, failure or malfunction of the
thermostat must be incorporated into and maintained
as part of the control system.
The TCN-890x features a quick-mount design that
saves time and simplifies installation. Two bases and
screws are provided with each thermostat, so it can be
mounted directly to drywall (plastic wall anchors are
provided) or a standard U.S. wallbox.
The setpoint knob has scales both in Fahrenheit
(54 to 82°F) and Celsius (12 to 28°C).
The TCN-8900 Series features separate Reverse
Acting/Direct Acting (RA/DA) outputs for heating and
cooling applications. To change the output from
heating to cooling, connect an external changeover to
the provided inputs on the screw terminals.
TCN-8900 Series models include an adjustable
Dead Band (DB).
• TCN-8901 has 0 to 10 VDC RA and DA outputs
that feature separate Proportional Band (PB)
• TCN-8906 has two On/Off RA and DA triac
outputs that feature separate differential
Use the Unoccupied feature, accessible through the
terminal block, to designate a night or unoccupied
setting, which can be operated by a timer or other
device. This state provides thermal protection by
maintaining a fixed offset of 9F° (5C°) from the
Replaces Part Numbers: TCN-8906-2161, CARTCN-8906-2161