Troubleshooting - Delta DZNT-104T Installation Manual

DZNT VAV / VVT Installation Guide

Troubleshooting

Troubleshooting network issues is simplified by following the recommended procedure of connecting NET
OUT from the proceeding box to NET IN on the current box and so on. If addressing of the devices also goes
up consecutively, all even addressed devices will be connected on the network one after the other, as well as
the odd addressed devices. A string of Offline devices will show itself as every other device on the network
Problem
Single Stat not online
All Stats downstream of a
network node not visible
Miscellaneous Stats not visible
Pattern of other Stats not
visible when a Stat is removed
Power
Caution: The DZNT product line requires a 24 VAC @ 15VA power supply – not
including output loading for its internally powered triac – typically an isolated Class II
transformer. More than one device – not including DCUs or V2 products – may be
connected to the same transformer, providing the transformer is properly sized,
including line losses, and polarity is observed between controllers (in regards to 24~
and GND).
The transformer must ONLY be used to provide power to other MS/TP devices and
field devices powered through its outputs. Auxiliary field devices (i.e., 4-20 mA
devices) that don't use ½ wave rectification must be powered separately.
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Possible Cause
Stat addressed incorrectly
24VAC polarity reversed on Termination Board
Cat5 cable not connected at stat terminal of Termination Board
Cat5 cable not connected at terminal of stat
Stat has wrong baud rate set
Stat plugged into network input or output terminal
Cat5 cable not connected at network output of last online Termination Board
Cat5 cable not connected at network input of first offline Termination Board
Cat5 cable not connected at ADP45-MSTP-Y if present
Faulty Cat5 cable between last online and first offline Termination Board
Live Ethernet cable connected at network output of last online Termination Board
Live Ethernet cable connected at network input of first offline Termination Board
Live Ethernet cable connected at stat terminal of first offline Termination Board
Live Ethernet cable connected at terminal of first offline stat
Total network segment cable length over 2000'
Combination of more than 1 of the following: missing ADP45-MSTP-LOOP connector,
stat not connected to Termination Board, faulty Cat5 cable
Offline stats have wrong baud rate set
Either missing ADP45-MSTP-LOOP connector or faulty Cat5 cable at last offline device
Document Edition 1.2