Installation and Maintenance Manual
74 VAV-SVX07A-EN
Troubleshooting
WARNING
Hazardous Service Procedures!
The maintenance and troubleshooting procedures recommended in this section of the manual
could result in exposure to electrical, mechanical or other potential safety hazards. Always refer
to the safety warnings provided throughout this manual concerning these procedures. When
possible, disconnect all electrical power including remote disconnect and discharge all energy
storing devices such as capacitors before servicing. Follow proper lockout/tagout procedures to
ensure the power can not be inadvertently energized. When necessary to work with live
electrical components, have a qualified licensed electrician or other individual who has been
trained in handling live electrical components perform these tasks. Failure to follow all of the
recommended safety warnings provided, could result in death or serious injury.
2. Measure the receiver output resistance by following the procedures.
• Make sure the black wire (GNS-SIGNAL) and the yellow wire (GND-POWER) are grounded
(see Figure 34, p. 74 for wiring diagrams).
• Make sure the receiver is powered up.
• Disconnect the SETPOINT wire (red) and the ZONE wire (white) from the host unit controller.
• Measure resistance between the grounded GND-SIGNAL wire and either the SETPOINT or
ZONE wire. Compare resistance measurements to those presented in Table 19, p. 75.
• If resistance is not correct replace receiver.
• When the test is complete, reset the receiver address to its previous setting.
Figure 34.
Table 18. Output failure modes of operation
Situation Zone Temperature Output Zone Setpoint Output
Receiver address = 000
11.17 kΩ, 72.5
o
F (22.5
o
C),
indefinitely
451 Ω, 72.5
o
F (22.5
o
C), indefinitely
Receiver address = 001 to 999
Receiver has powered up, but has not
received a communication from
sensor.
11.17 kΩ, 72.5
o
F (22.5
o
C) 451 Ω, 72.5
o
F (22.5
o
C)
Receiver address = 001 to 999
Receiver does not receive a
communication within 35 minutes
from the sensor it is associated with
Open Open
Receiver has no power Open Open
Thermistor in sensor has failed to
either open or close
Open Normal value
Setpoint potentiometer has failed to
either open or close
Normal value Open