Trane Precedent TSC060, Installation Operation & Maintenance

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T_C-IOM-2A
38
Trouble Shooting
ReliaTel Control
The RTRM has the ability to provide the
service personnel with some unit diag-
nostics and system status information.
Before turning the main power discon-
nect switch “Off”, follow the steps below
to check the ReliaTel Refrigeration Mod-
ule (RTRM). All diagnostics & system
status information stored in the RTRM will
be lost when the main power is turned
“Off”.
HAZARDOUS VOLTAGE!
HIGH VOLTAGE IS PRESENT AT THE
TERMINAL BLOCK OR UNIT
MOUNTED DISCONNECT SWITCH.
To prevent injury or death from electrocu-
tion, it is the responsibility of the technician
to recognize this hazard and use extreme
care when performing service procedures
with the electrical power energized.
1. Verify that the Liteport LED on the
RTRM is burning continuously. If the
LED is lit, go to Step 3.
2. If the LED is not lit, verify that 24 VAC
is presence between J1-1 and J1-2.
If 24 VAC is present, proceed to
Step 3. If 24 VAC is not present,
check the unit main power supply,
check transformer (TNS1). Proceed to
Step 3 if necessary.
3. Utilizing “Method 1” or “Method 2” in
the “System Status Diagnostic” sec-
tion, check the following:
System status
Heating status
Cooling status
If a System failure is indicated, pro-
ceed to Step 4. If no failures are indi-
cated, proceed to Step 5.
4. If a System failure is indicated, recheck
Steps 1 and 2. If the LED is not lit in
Step 1, and 24 VAC is present in
Step 2, the RTRM has failed. Re-
place the RTRM.
5. If no failures are indicated, use one of
the TEST mode procedures de-
scribed in the “Unit Start-Up” section
to start the unit. This procedure will al-
low you to check all of the RTRM out-
puts, and all of the external controls
(relays, contactors, etc.) that the
RTRM outputs energize, for each re-
spective mode. Proceed to Step 6.
6. Step the system through all of the
available modes, and verify operation
of all outputs, controls, and modes. If a
problem in operation is noted in any
mode, you may leave the system in
that mode for up to one hour while
troubleshooting. Refer to the se-
quence of operations for each mode,
to assist in verifying proper operation.
Make the necessary repairs and pro-
ceed to Steps 7 and 8.
7. If no abnormal operating conditions
appear in the test mode, exit the test
mode by turning the power “Off” at
the main power disconnect switch.
8. Refer to the individual component test
procedures if other microelectronic
components are suspect.
System Status Checkout Procedure
“System Status” is checked by using
one of the following two methods:
Method 1
If the Zone Sensor Module (ZSM) is
equipped with a remote panel with LED
status indication, you can check the unit
within the space. If the ZSM does not
have LED’s, use Method 2.
BAYSENS010B, BAYSENS011B,
BAYSENS019A, BAYSENS020A,
BAYSENS021A & BAYSENS023A all
have the remote panel indication feature.
The LED descriptions are listed below.
LED 1 (System)
“On” during normal operation.
“Off” if a system failure occurs or the LED
fails.
“Flashing” indicates test mode.
LED 2 (Heat)
“On” when the heat cycle is operating.
“Off” when the heat cycle terminates or
the LED fails.
“Flashing” indicates a heating failure.
LED 3 (Cool)
“On” when the cooling cycle is operating.
“Off” when the cooling cycle terminates or
the LED fails.
“Flashing” indicates a cooling failure.
LED 4 (Service)
“On” indicates a clogged filter.
“Off” during normal operation.
“Flashing” indicates an evaporator fan fail-
ure
Below is the complete listing of failure in-
dication causes.
System Failure
Check the voltage between terminals 6
and 9 on J6, it should read approxi-
mately 32 VDC. If no voltage is present,
a System failure has occurred. Refer to
Step 4 in the previous section for the
recommended troubleshooting proce-
dure.
Cooling Failure
1. Cooling and heating set point (slide
pot) on the zone sensor has failed.
Refer to the “Zone Sensor Test Pro-
cedure” section.
2. Zone temperature thermistor ZTEMP
on ZTS failed. Refer to the “Zone
Sensor Test Procedure” section.
3. CC1 or CC2 24 VAC control circuit
has opened, check CC1 & CC2 coils,
and any of the controls below that ap-
ply to the unit (HPC1, HPC2).
4. LPC1 has opened during the 3 minute
minimum “on time” during 4 consecu-
tive compressor starts, check LPC1 or
LPC2 by testing voltage between
the J1-8 & 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
1. 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.
2. Clogged filter switch has closed, check
the filters.