Troubleshooting; Alarm Issues; Alarm, (False) Fan Fail; Alarm, (False) Low Limit (Freeze Stat) - KMC Controls FlexStat Operation Manual

Troubleshooting

Alarm Issues

Alarm, (False) Fan Fail

• Check configuration. Be sure the Fan Status
option is not selected when there is no sensor/
switch for it.
• Check that the IN2 (fan status) input pull-up
resistor switches are fully latched in the correct
positions. Any passive, dry contact should use
the 10K Ohm setting. (See the Connections and
Wiring section of the relevant FlexStat Installa-
tion Guide.)
• Check IN2 (fan status) input wiring.
• Check the connected fan status sensor/switch.
• Using BACstage or TotalControl, check that AI2
(fan status) is not configured as "Out Of Service."

Alarm, (False) Low Limit (Freeze Stat)

• Check the Low Limit Alarm setting—see Damper
Setup on page 6.
• Check configuration. Be sure the Economizer
option is not selected when there is no mixed air
temperature sensor.
• Check that the IN3 (mixed air temp.) input
pull-up resistor switches are fully latched in the
correct positions (see the Connections and Wir-
ing section of the relevant FlexStat Installation
Guide).
• Check IN3 (mixed air temperature) input wiring.
• Check the connected mixed air temperature sensor.
• Using BACstage or TotalControl, check that AI3
(mixed air temp.) is not configured as "Out Of
Service."
NOTE: After a low limit alarm is generated, the
fan will not run until after the FlexStat is
restarted. (See Resetting the FlexStat on
page 16.)

Alarm, (False) Space Temp. or Humidity

• See Alarms on page
• See Temperature Reading Is Incorrect on page
• See Temperature Setpoint Is Not Maintained on
page 23.
• Using TotalControl, adjust the limits or time
delay.
FlexStat
13.

Communication Issues

KMD-5576 Communication Issues

• Upgrade to the latest version of BACstage (ver.
2.4.0.25 or later required).
• Check the settings for the USB port on the
computer (Device Manager > Ports) and the
MS/TP port in BACstage (Access > Connection
Parameters).
• Reduce the Max Master number down to the
minimum needed for that network—see (Ad-
vanced) BACnet Communications on page
• Install latest driver and check latency settings.
See Latency Settings for KMD-5576 Service Bul-
letin (SB0308A) on the KMC web site.
• See also MS/TP Network Communication
below.

MS/TP Network Communication Issues

• Check MAC address and device instance num-
bers (especially for duplicate numbers on the
network)—see (Advanced) BACnet Communica-
tions on page 8 and (Advanced) BACnet Device
Properties on page
• Check that EOL switches are fully latched in the
correct positions (see the relevant FlexStat Instal-
lation Guide).
• Check baud rate—see (Advanced) BACnet Com-
munications on page
• Reduce the Max Master number down to the
minimum needed for that network—see (Ad-
vanced) BACnet Communications on page
• See Wiring Issues on page
23.
20
9.
8.
26.
Operation Guide, Rev. K
8.
Issues
8.