Troubleshooting
54
RT-SVX22J-EN
Cooling Failure
•
Cooling and heating set point (slide pot) on the zone
sensor has failed. Refer to the “Zone Sensor Test
Procedure” section.
•
Zone temperature thermistor ZTEMP on ZTS failed.
Refer to the “Zone Sensor Test Procedure” section.
•
CC1 or CC2 24 VAC control circuit has opened, check
CC1 & CC2 coils, and any of the controls below that
apply to the unit (HPC1, HPC2).
•
LPC1 has opened during the 3 minute minimum “on
time” during 4 consecutive compressor starts, check
LPC1 or LPC2 by testing voltage between the J1-1 & J3-
2 terminals on the RTRM and ground. If 24 VAC is
present, the LPC’s has not tripped. If no voltage is
present, LPC’s has tripped.
Service Failure
•
If the supply fan proving switch has closed, the unit will
not operate (when connected to RTOM), check the fan
motor, belts, and proving switch.
•
Clogged filter switch has closed, check the filters.
•
If the condensate overflow switch is closed, the unit
will not operate. Make sure the float switch is not in a
tripped condition, and check for an "open" between
wires connecting to RTOM J6-1, J6-2 (ReliaTel
controls).
Simultaneous Heat and Cool Failure
•
Emergency Stop is activated
Method 2
The second method for determining system status is done
by checking voltage readings at the RTRM (J6). The system
indication descriptions and the approximate voltages are
listed below.
System Failure
Measure the voltage between terminals J6-9 & J6-6.
Normal Operation = approximately 32 VDC
System Failure = less than 1 VDC, approximately 0.75 VDC
Test Mode = voltage alternates between 32 VDC & 0.75
VDC
Heat Failure
Measure the voltage between terminals J6-7 & J6-6.
Heat Operating = approximately 32 VDC
Heat Off = less than 1 VDC, approximately 0.75 VDC
Heating Failure = voltage alternates between 32 VDC &
0.75 VDC
Cool Failure
Measure the voltage between terminals J6-8 & J6-6.
Cool Operating = approximately 32 VDC
Cool Off = less than 1 VDC, approximately 0.75 VDC
Cooling Failure = voltage alternates between 32 VDC &
0.75 VDC
Service Failure
Measure the voltage between terminals J6-10 & J6-6.
Clogged Filter = Approximately 32 VDC.
Normal = Less than 1 VDC, approximately 0.75 VDC Fan
Failure = voltage alternates between 32 VDC & 0.75 VDC.
To use LED’s for quick status information at the unit,
purchase a BAYSENS110* ZSM and connect wires with
alligator clamps to terminals 6 through 10. Connected each
respective terminal wire (6 through 10) from the Zone
Sensor to the unit J6 terminals 6 through 10.
Note:
If the system is equipped with a programmable
zone sensor, (BAYSENS119*, or BAYSENS023A),
the LED indicators will not function while the
BAYSENS110* is connected.
Resetting Cooling and Ignition Lockouts
Cooling Failures and Heating Lockouts are reset in an
identical manner. Method 1 explains resetting the system
from the space; Method 2 explains resetting the system at
the unit.
Note:
Before resetting Cooling Failures and Ignition
Lockouts check the Failure Status Diagnostics by
the methods previously explained. Diagnostics will
be lost when the power to the unit is disconnected.
Method 1
To reset the system from the space, turn the “Mode”
selection switch at the zone sensor to the “Off” position.
After approximately 30 seconds, turn the “Mode”
selection switch to the desired mode, i.e. Heat, Cool or
Auto.
Method 2
To reset the system at the unit, cycle the unit power by
turning the disconnect switch “Off” and then “On”.
Lockouts can be cleared through the building
management system. Refer to the building management
system instructions for more information.
Zone Temperature Sensor (ZTS)
Service Indicator
The ZSM SERVICE LED is a generic indicator, that will
signal the closing of a Normally Open switch at any time,
providing the Indoor Motor (IDM) is operating. This
indicator is usually used to indicate a clogged filter, or an
air side fan failure.
Summary of Contents for Precedent THC036E
Page 37: ...Installation RT SVX22J EN 37 Figure 51 Examples...
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