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Instruction Manual IM02602008E - Rev. D
Transformer Temperature Controllers IM02602008E - Rev. D May 2019 www.eaton.com
1. Introduction
The content of this manual is organized into seven sec-
tions, and three appendixes, as follows:
• Introduction
• Installation
• Operating Functions
• Operating Procedures
• Maintenance and Repair
• Troubleshooting
• Specifications
• Appendix A - Programming Quick Reference Guide
• Appendix B - Modbus Registers
1.1 Product Overview
Eaton
®
Transformer Temperature Controllers monitor the
temperature of up to three ventilated, dry-type transformer
windings. They also monitor the ambient temperature with-
in the cabinet in which the transformer is installed.
These temperatures are detected by thermocouples placed
within the transformer windings and inside the cabinet.
If winding temperatures exceed a preset limit (setpoint)
relays are tripped to start cooling fans to reduce tempera-
tures and prevent equipment damage. If higher trip and
alarm winding temperature setpoints are reached, Form C
contacts may be used to trip a remote alarm and ultimately
trip the transformer offline.
Three models of the transformer temperature controller
(TC) are available; the TC-50, the TC-50 Modbus, and the
TC-100. The TC-100 includes Modbus and has advanced
features for discrete inputs, monitoring, and data logging.
All models have a common appearance but vary in function-
ality. The functionality described in Section 4.1.2 -Operating
the TC Manually, and Section 4.2 -Local Operation, apply to
all models unless otherwise noted in a heading or the text.
All TC models have a front panel that provides a communi-
cations interface between the controller and an operator.
The panel consists of an 9-character LED display, 9 discrete
LEDs, and 9 pushbuttons. Communication is also possible
using a laptop computer connected to a front USB port, or
through Modbus (on the TC-50 Modbus, and the TC-100
models
A sealed controller unit processes all data received.
All TC models are available in two versions: a barrier cabi-
net version (Section 1.2) or a flush, bezel-mounted version
(Section 1.3).
The features of each model are described below.
All models (TC-50, TC-50 Modbus, and TC-100) have these
standard features:
• Operates on 100 to 240 Vac, 50 or 60 Hz power.
• LED display shows conditions and values
• Panel LEDs indicate system status.
• Cooling fans turn on automatically when temperatures
exceed a setpoint, or a trip relay shuts down the trans-
former.
• Setpoints can be used to turn on either fan, or turn on an
Alarm or Trip relay for a high temperature condition.
• Alarm and trip relays can function as fail-safe relays (nor-
mally energized when the TC is powered up).
• Alarm buzzer sounds but can be silenced without cancel-
ing the alarm.
• Certifications include Underwriter’s Laboratories (UL
®
), to
Standard 873, CSA C22.2 No. 24-93.
• Provides 4-20 mA analog signal for remote indication or
use with SCADA systems.
• Unit can be used for single-phase transformers, or other
devices, by selecting or deselecting individual elements.
• Fans can be operated automatically for short periods to
prevent motor seizing.
The TC-50 Modbus model has all of the standard features,
plus:
• RS-485 connection for Modbus communications.
The TC-100 model has all of the standard features, plus
these additional features:
• RS-485 connection for Modbus communications.
• Monitors two discrete inputs, such as opening or closing
fan louvers or doors.
• Provides automatic monitoring and logging functions, and
temperature trending, to analyze operation and achieve
faster restoration.