Trane VAV VV550 LonTalk, Руководство по установке и эксплуатации

Страница: 89 / 116

VAV-SVP01A-EN 89
Troubleshooting
Wired Zone Sensor Failure Procedures
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. 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.
In the event that the VV550 reports an incorrect zone temperature, properly inspect the following:
1. Actual room temperature is higher or lower than what the VV550 reads
• Check the location and installation of the zone sensor. Change the calibration factor in the
VAV VV550 Controller setup screens.
Note: If Zone sensor is off more than ± 2 degrees continue to number 2.
2. Zone sensor wired incorrectly
• Check wiring for the correct connections. See VAV Startup/Check out Procedure chapter for
the wiring specifications for VV550
3. Defective zone sensor
• Disconnect the zone sensor terminal plug from the VV550 and using an Ohmmeter, measure
the resistance across the terminals 1 and 2. Compare the resistance to temperature using
Table 19, p. 90 . The resistance should shown value should be within ± 2 degrees near those
measured with an accurate temperature measuring device. If not, the zone sensor needs to
be replaced.
4. Defective wiring or VV550
• With wires still connected to VAV VV550, disconnect zone sensor wires and check voltage
(DC) from wires that were connected to terminals 1 and 2 of zone sensor. You should
measure 5VDC. If 5VDC not present then see if the VAV VV550 is outputting 5VDC. This can
be done by disconnecting the wires on the VAV VV550 on terminals TB3-1 and TB3-2 and
measure the VDC. It should be 5VDC. If you have 5VDC at the VV550 the wires going to the
zone have an open. If 5VDC is not present check incoming power to the VV550 board on TB1-
1 24VAC input and TB1-2 should measure 24VAC ± 10%. If you measure the proper voltage
at on TB1-1 24VAC input and TB1-2 and no voltage at TB3-1 and TB3-2 replace VV550.
5. Zone sensors shorted out
• Check the resistance across the wires. Disconnect wires from VV550 and zone sensor making
sure the ends are not touching each other and measure resistance. It should be infinity or
no conductivity. If lower resistance is shown wires are shorted together and needs to be
replaced.