Cte-5202 Troubleshooting; Display Is Blank; Setpoint Is Not Maintained; Temperature Reading Is Incorrect - KMC Controls CTE-5202 Application Manual

CTE-5202 Troubleshooting

Display Is Blank

• If the display comes on for no more than 30
seconds after a button is pushed and then blanks
out, Display Blanking is enabled in the SYS-
TEM menu. See Change Configuration on page
• Check for a tripped circuit breaker to the trans-
former.
• Check for proper supply voltage from the
transformer and that the transformer has enough
capacity (VA) for all connected devices See their
respective data sheets and
24-Volt Power Application Note

Setpoint Is Not Maintained

• Check that room temperature is being sensed
correctly. See

Temperature Reading Is Incorrect

on page 10.
• Check that the appropriate sequence is selected
in the SYSTEM menu. See
tion on page 6 and the relevant sample applica-
tion.
• If changeover is used on AI1, check the sensor
and the changeover setting in the ADVANCE
menu. If a resistor is used on AI1 to force a
changeover without a temperature sensor, the
value of the resistor may be too high or too
low. See External Input (AI1) on page
Configuration on page
application.
• If a setback switch/relay is used on AI1, the
switch may be (stuck) in the setback position. See
page 36.
• If an override switch/relay is used on AO1, the
switch may be (stuck) in the override position.
See page 18, page 34, and
• Check settings of auxiliary flow and other limits
as relevant in the LIMITS menu. See
Configuration on page
• If the HVAC system has trouble recovering from
the unoccupied setback to the occupied setpoint
during very cold weather, adjust the setback in
the ADVANCE menu. See
tion on page 6.
General Information (All Applications)
Tips for Connecting
(AN0604D).
Change Configura-
5, Change
6, and the relevant sample
page 46.
Change
6.
Change Configura-
• If space temperature is overshooting the setpoint
or oscillating, try increasing the proportional
band by a degree in the ADVANCE menu. If
the problem persists, try increasing the integral
value slightly (up to 20%). If the problem still
6.
persists, try setting the integral value to 0. (The
optimal integral value is dependent on the
characteristics of the particular space and HVAC
system.) See Change Configuration on page
Temperature Reading Is Incorrect
• Check that the correct °F/C temperature scale
is selected in the SYSTEM menu. See
Configuration on page
• If the discrepancy is small, adjust the room
temperature offset in the ADVANCE menu. See
Change Configuration on page
• Check that the thermostat is NOT mounted on
an exterior wall, mounted on or near a large
thermal mass (e.g., concrete block wall), blocked
from normal air circulation by obstructions,
exposed to heat sources (e.g., lights, computers,
copiers, coffee makers) or to sunlight (at any
time of the day), exposed to drafts from win-
dows or air vents, or exposed to air flow through
the conduit from leaks in plenum ducts (put
plumber's putty or other sealant inside conduit
to block air leaks).

Wiring Issues

• Check for correct wiring for the application. See
Connections on page 5
tion examples in this document.
• Remove the thermostat from the backplate and
inspect the terminals for loose wires. See the
CTE-5202 Installation
• Check the wiring at the connected devices.
• Use a voltmeter and ohmmeter to check the
terminals for expected values.
NOTE: Wiring must be adequate to avoid
excessive voltage drop on long
runs! Allow plenty of "cushion" in
measurements A meter may be too slow
to register transient dips or peaks during
startup.
10
Change
6.
6.
and the various applica-
Guide.
CTE-5202 Applications Guide, AN0912A Rev. D
6.