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Overview
1
Overview
1.1. QUALITROL
Intelligent Transformer Monitor
The Model 118 ITM Intelligent Transformer Monitor (ITM) can monitor up to three
thermocouples in ventilated dry-type transformer windings, display the current winding
temperatures, and operate relays by comparing the highest of the three winding
temperatures to stored set point temperatures.
The ITM provides the following standard features:
Monitors three, type K thermocouples.
Displays each of the three thermocouple temperatures as well as the maximum
temperature stored.
Displays the channel that caused the stored maximum temperature.
Operates high-contact rating SPST relays with fuse-protected contacts to control cooling
FANs.
A Manual Fan Control provides the capability to force the FANs to turn ON.
A yellow LED indicates that the FANs are ON.
A Fan Exerciser Circuit turns the FANs ON for a short time at periodic intervals (ON time
and intervals are programmable).
Operates a relay with an SPDT contact when one of the inputs exceeds the ALARM
setting.
A red LED indicates that the ALARM is ON.
An internal audible device (buzzer) sounds when the ALARM is ON. The audible device
can be silenced by the Front Panel Silence button without changing the state of the
ALARM relay.
The ALARM relay default state is normally energized so that the ALARM is initiated upon
power failure (failsafe). All other relay default states are normally de-energized (non-
failsafe). The normal state of all relays, except for the Fan Control Relays, may be
changed via the USB port and software, allowing for customer configuration.
RELAY 4 and RELAY 5 are available for use depending on application. The normal state
of these relays may be set by the user software. A red LED indicates the status RELAY
4 and 5
If a thermocouple goes open circuit, it is detected, the ALARM operates, and the faulty
channel displays “- - -”. A failed thermocouple will not cause a TRIP.
Operates a relay with an SPDT contact when one of the inputs exceeds the TRIP
setting.
A red LED indicates that the TRIP relay is ON
A TEST function shows the stored set points, shows the internal temperature of the ITM,
and tests the LCD display, relay status LEDs, and the buzzer.
