Programmable & Digital Zone Sensor Test - Trane TH 150-300 Series Installation, Operation And Maintenance Manual

Method 2
Testing the LED with an analog Ohmmeter. Connect
Ohmmeter across LED in one direction, then reverse the
leads for the opposite direction. The LED should have at
least 100 times more resistance in reverse direction, as
compared with the forward direction. If high resistance in
both directions, LED is open. If low in both directions, LED
is shorted.
Method 3
To test LEDs with ZSM connected to unit, test voltages at
LED terminals on ZSM. A measurement of 32 Vdc, across
an unlit LED, means the LED has failed.
Table 16. Default operation for mechanical ZSM (CV
only)
J6 Input/Connection
(a) LED will not come on while heating
J6-7 - Heat indication
LED will not flash during heat fail
(a) LED will not come on while cooling
J6-8 - Cool indication
LED will not flash during cool fail
(a)
J6-9 - System indication
LED will not come on while unit has power
(sys on)
(a)
J6-10 - Service LED will not come on when CFS or FFS
indication trips
(a)these connections are only on certain model ZSMs
Note: Measurements should be made from LED common
(ZSM terminal 6 to respective LED terminal). Refer
to Table 16, p. 45.
Table 17. System mode and fan selection
Resistance Zone Sensor
Valves Unit/Fan
(K-Ohms) Mode
2.32 Off/Auto
4.87 Cool/Auto
7.68 Auto/Auto
10.77 Off/On
13.32 Cool/On
16.13 Auto/On
19.48 Heat/Auto
27.93 Heat/On
Emergency
35.0
Heat/Auto
Emergency
43.45
Heat/On
Out of Range
INVALID/Short
(Short)
Out of Range
INVALID/Open
(Open)
RT-SVX25J-EN
If no input/connection this
happens
(a)
Local Unit Local Fan
Mode Mode
Off Auto
Cool Auto
Auto Auto
Off On
Cool On
Auto On
Heat Auto
Heat On
Emergency
Auto
Heat
Emergency
On
Heat
Invalid (CV),
Invalid
Auto (VAV)
Invalid (CV), Off
Invalid
(VAV)
Programmable & Digital Zone
Sensor Test
Testing Serial Communication Voltage
1. Verify 24 Vac is present between terminals J6-14 and
J6-11.
2. Disconnect wires from J6-11 and J6-12. Measure the
voltage between J6-11 and J6-12, should be about
32 Vdc.
3. Reconnect wires to terminals J6-11 and J6-12. Measure
voltage again between J6-11 and J6-12, voltage should
flash high and low every 0.5 seconds. The voltage on
the low end will measure about 19 Vdc, while the
voltage on the high end will measure from
approximately 24 to 38 Vdc.
4. Verify all modes of operation, by running the unit
through all of the steps in the "Test Modes" section
discussed in "Start Up, " p.
5. After verifying proper unit operation, exit the test
mode. Turn the fan on continuously at the ZSM, by
pressing the button with the fan symbol. If the fan
comes on and runs continuously, the ZSM is good. If
you are not able to turn the fan on, the ZSM is
defective.
ReliaTel Refrigeration Module (RTRM)
Default Chart
If the RTCI loses input from the building management
system, the RTRM will control in the default mode after
approximately 15 minutes. If the RTRM loses the Heating
and Cooling setpoint input, the RTRM will control in the
default mode instantaneously.
The temperature sensing thermistor in the Zone Sensor
Module is the only component required for the "Default
Mode" to operate.
Unit Operation Without a Zone Sensor
This procedure is for temporary operation only. The
economizer and condenser fan cycling functions are
disabled.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
1. Open and Lock the unit disconnect switch.
2. Remove the Outside Air Sensor (OAS) from the
condenser section of unit.
3. Use two (2) wire nuts, to individually cap the wires.
Troubleshooting
35" .
45