41RT-SVX31A-EN
If the switch remains closed, and the
IDM is turned “On”, the SERVICE LED
will be turned “On” again after the 2
(±1) minute ignore delay.
This LED being turned “On”, will have
no other affect on unit operation. It is an
indicator only.
Fan Failure Switch
When the “Fan Failure” switch is wired
to the RTOM, the LED will remain flash-
ing the entire time the fan proving
switch is closed, indicating a fan fail-
ure, and it will shut the unit operations
down.
Zone Temperature Sensor (ZTS) Test
Note:
These procedures are not for
programmable or digital models and are
conducted with the Zone Sensor Module
electrically removed from the system.
Test 1
Zone Temperature Thermistor
(ZTEMP)
This component is tested by measuring
the resistance between terminals 1 and
2 on the Zone Temperature Sensor. Be-
low are some typical indoor tempera-
tures, and corresponding resistive val-
ues.
Test 2
Cooling Set Point (CSP) and Heating
Set Point (HSP)
Nominal ZTEMP Nominal CSP or
Resistance HSP Resistance
50 F° 10.0 C°
19.9 K-Ohms 889 Ohms
55 F° 12.8 C°
17.47 K-Ohms 812 Ohms
60 F° 15.6 C°
15.3 K-Ohms 695 Ohms
65 F° 18.3 C°
13.49 K-Ohms 597 Ohms
70 F° 21.1 C°
11.9 K-Ohms 500 Ohms
75 F° 23.9 C°
10.50 K-Ohms 403 Ohms
80 F° 26.7 C°
9.3 K-Ohms 305 Ohms
85 F° 29.4 C°
8.25 K-Ohms 208 Ohms
90 F° 32.2 C°
7.3 K-Ohms 110 Ohms
Zone
Tem
erature
The resistance of these potentiometers
are measured between the following
ZSM terminals. Refer to the chart
above for approximate resistances at
the given setpoints.
Cool SP = Terminals 2 and 3
Range = 100 to 900 Ohms approxi-
mate
Heat SP = Terminals 2 and 5
Range = 100 to 900 Ohms approximate
Test 3
System Mode and Fan Selection
The combined resistance of the Mode
selection switch and the Fan selection
switch can be measured between termi-
nals 2 and 4 on the Zone Sensor. The
possible switch combinations are
listed below with their corresponding
resistance values.
Test 4
LED Indicator Test, (SYS ON, HEAT,
COOL & SERVICE)
Method 1
Testing the LED using a meter with di-
ode test function. Test both forward and
reverse bias. Forward bias should mea-
sure a voltage drop of 1.5 to 2.5 volts,
depending on your meter. Reverse bias
will show an Over Load, or open circuit
indication if LED is functional.
Method 2
Testing the LED with an analog Ohm-
meter. 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 com-
pared 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 LED’s 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.
Note:
Measurements should be made from
LED common (ZSM terminal 6 to
respective LED terminal). Refer to the
Zone Sensor Module (ZSM) Terminal
Identification table at the beginning of
this section.
Programmable & Digital Zone Sensor
Test
Testing serial communication
voltage
1. Verify 24 VAC is present between
terminals J6-14 & 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 mea-
sure from approximately 24 to 38
VDC.
4. Verify all modes of operation, by run-
ning the unit through all of the steps
in the “Test Modes” section dis-
cussed in “Unit Start-Up”.
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 defec-
tive.
ReliaTel Refrigeration Module
(RTRM) Default Chart
If the RTCI loses input from the build-
ing 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 de-
fault mode instantaneously. The tem-
perature sensing thermistor in the Zone
Trouble Shooting
To Next Page
Loading...
Need help?
General
