Johnson Controls TEC3612 User Manual

Table 9: Troubleshooting details
Symptom Probable causes Solutions
The two-pipe fan coil/VAV
system does not have a
changeover sensor and switch
connected, or the sensor/switch
has failed.
1. Check the wiring of the supply temperature
sensor/switch.
2. Verify that the changeover is set up
correctly for the type of sensor attached
(sensor or switch).
The changeover temperature
is sensing a hot supply, but the
controller requests cooling.
1. Verify that the supply is not in heating
mode. If it is, nothing can be done from the
TEC.
2. Check the wiring of the supply temperature
sensor or switch.
3. Check the placement of the supply
temperature sensor or switch.
4. Verify that the changeover is set up
correctly for the type of sensor attached
(sensor or switch).
The controller displays Idle
with a Unit Status of Cooling
Unavailable due to
Changeover despite being above
cooling setpoint, or with a status
of Heating Unavailable due
to Changeover despite being
below the setpoint.
Changeover temperature is
sensing a cold supply, but the
controller requests heating.
1. Verify that the supply is not in cooling
mode. If it is, nothing can be done from the
TEC.
2. Check the wiring of the supply temperature
sensor or switch.
3. Check the placement of supply temperature
sensor or switch.
4. Verify that the changeover is set up
correctly for the type of sensor attached
(sensor or switch).
The Control Mode is set to
Cooling Mode, but the controller
requests heating.
Change the Control Mode to Auto or Heating.The controller displays Idle
with a Unit Status of Cooling
Unavailable due to Control
Mode despite being above cooling
setpoint, or with a status of
Heating Unavailable due to
Control Mode despite being
below the setpoint.
The Control Mode is set to
Heating Mode, but the controller
requests cooling.
Change the Control Mode to Auto or Cooling.
The staged equipment shuts off
above the cooling setpoint or
below the heating setpoint when
the PID is running on the TEC.
If the unit is in On/Off Control
mode, this does not apply.
The PID control algorithm
minimizes overshoot and
energy usage for the particular
equipment and zone, and may
cycle the equipment prior to
reaching setpoint.
Expected behavior.
The staged equipment cycles too
rapidly or too slowly when the PID
is running on the TEC.
The control band around the
setpoint is determined by the
minimum on/off times and is set
incorrectly for the equipment,
zone, or user preference. There
is a tradeoff between reduced
control band size and increased
energy usage and equipment
wear from increased cycling.
1. Verify that equipment minimum on/off
times are set correctly.
2. If the default deadband around the
setpoint does not provide the required
temperature control, set Temp Control
Setup to Deadband Override and set the
Deadband parameter to the preferred
value.
The controller provides an error
when trying to upgrade firmware.
The firmware on the USB drive
is below the minimum required
version. Error code 1025.
Please use firmware version 3.0.2.xxxx (for
networked models) or 2.0.2.xxxx (for wireless
models) or higher. A reboot is required to clear
the Firmware Mismatch fault that occurs.
TEC3000 Series On/Off or Floating Fan Coil Thermostats Quick Start Guide 25

Johnson Controls TEC3612 Specifications

General

Brand	Johnson Controls
Model	TEC3612
Category	Controller
Language	English