User's Guide

DIGITAL DRY TRANSFORMER
2019-03-19 12/57
2.2 Communications Module
The Communications Module is the Wi-Fi hotspot and is installed out-
side of any metallic enclosure (for easier accessibility and to allow
connectivity). As a security precaution, an ABB-supplied NFC/RFID
card must be detected to enable the Wi-Fi.
The communications module is equipped with a GPS device that de-
tects the transformer location and maintains an accurate system
clock.
The typical range of TXpert Wi-Fi communications is 50 to 92 meters.
The range is impacted by interference, location and environmental
conditions.
2.3 Relay Module (Fan Control) (Optional)
The relay module is mounted on a core clamp inside the transformer enclosure and attaches to the fan
circuit. It is used by the TXpert main module (via a custom cable) to monitor and control the fans
The TXpert turns on the fan(s) when the transformer is
getting too hot, the load is too large, or to periodically
exercise the fan. The fan is turned off when the trans-
former cools and the load is reduced.
The TXpert calculates when to turn on and off the fans
based on algorithms with inputs including transformer
load, measured coil temperatures, calculated hot spot
temperature, and fan current.
The relay module contains two relays (25A) to perform
switching and circuitry to allow monitoring of the fan
current.
Connector
Relay
Circuit
Function
L1 In
1
Source Line-Voltage Input
N1 In
1
Source Neutral Input
N1 Out
1
Switched Neutral Output
L1 Out
1
Switched Line Output
L2 In
2
Source Line-Voltage Input
N2 In
2
Source Neutral Input
N2 Out
2
Switched Neutral Output
L2 Out
2
Switched Line Output
Figure 3
Figure 4