BAS-SVX10F-EN 33
Maintenance and Troubleshooting
Measuring Output Resistance
Measure output resistance as follows, according to sensor type.
Display Sensors
For display sensors, measure the outputs for zone temperature, setpoints, heat setpoint, and
system/fan mode as described:
1. Ensure that the GROUND (terminal 10) and the SI
GNAL COMMON (terminal 2) wires share a
common ground with the transformer.
2. To measure zone temperature resistance, disconnect the ZONE
TEMP (terminal 1) wire from the
sensor. Measure between the ZONE TEMP (terminal 1) and SIGNAL COMMON (terminal 2).
Compare resistance measurements to those in Table 1, p. 34.
3. To measure setpoint resistance:
• For s
ingle setpoint systems, disconnect the SETPOINT (terminal 3) wire from the sensor.
Measure between the SETPOINT (terminal 3) and the SIGNAL COMMON (terminal 2).
Compare resistance measurements to those in Table 1, p. 34.
• For dual
setpoints systems, disconnect the HEAT SETPOINT (terminal 5) wire from the
sensor. Measure between the HEAT SETPOINT (terminal 5) and the SIGNAL COMMON
(terminal 2). Compare resistance measurements to those in Table 1, p. 34.
4. To measure the system/fan mode res
istance, disconnect the SYS/FAN MODE (terminal 4) wire
from the sensor. Measure between the SYS/FAN MODE (terminal 4) and the SIGNAL COMMON
(terminal 2). Compare resistance measurements to those in Table 2, p. 34.
NOTICE:
Potential Equipment Damage!
Because the output circuits are not electrically powered, resistance can be measured without
risk of damage to the volt-ohm meter. However, damage to the volt-ohm meter could
potentially result if terminal 11 (24 VAC/VDC) is inadvertently contacted.
All Models Other Than the Display Sensor
For all other wired sensors, measure the outputs for temperature and setpoints and, if applicable,
the system/fan mode and heat setpoint:
1. To measure zone temperature resistance, measu
re between SIGNAL COMMON (terminal 2)
and ZONE TEMP (terminal 1). Compare resistance measurements to those in Table 1, p. 34.
2. To measure setpoint resistance:
• For single setpoint sy
stems, measure between SIGNAL COMMON (terminal 2) and
SETPOINT (terminal 3).
• For dual
setpoint system, measure between SIGNAL COMMON (terminal 2) and CSP
(terminal 3), and between SIGNAL COMMON (terminal 2) and HSP (terminal 5).
Compare resistance measurements to those
in Table 1, p. 34.
3. To measure the system/fan mode re
sistance, measure between SIGNAL COMMON (terminal 2)
and MODE (SYS/FAN SWITCH) (terminal 4). Compare resistance measurements to those in
Table 2, p. 34.
Note: The
output circuits are not electrically powered; consequently, resistance can be
measured without risk of damage to the volt-ohm meter.
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