Eaton Contactor Overload Relay – EMT6 Series Thermistor Overload Relays

The EMT6 series of thermistor overload relays from Eaton monitors the thermistor sensors used for monitoring temperature and switch off the power relay in the event of overheat in the machinery. Designed to offer a large variety of motor control in many situations, these thermistor overload relays protect machinery against overtemperature and extends the operational life of your control circuits. Heavy duties can cause high temperatures and overloads, whether, on the machines themselves, the bearings, gears, and coolants, these relays receive the corresponding signal and trip the motor contactor. Whilst the EMT6 relay models protect against overheating, there are a variety of models within the series able to protect against voltage loss, monitor short-circuiting, and have the ability to switch between manual and automatic switching off giving users the ultimate control and machine protection.

With these thermistor overload relays the motor current can also be used to monitor motor overtemperature in addition to the indirect method of temperature monitoring. For this, the motor manufacturer implements integral thermistors in the motor windings. The thermistors are then monitored by the thermistor overload protection relay for complete motor protection for your automation and control circuits.

Eaton’s EMT6 series relays offer motor control within a multitude of environments. DIN rail mountable, with a contact voltage rating of 400 V ac, 2W power rating and an ambient temperature range of -25 to +45 °C, this range of overload relays provides an affordable and efficient way for you to protect your motors.

Features and Benefits:

• Auto-reset (automatic and manual reset models available)
• 400 V ac contact voltage rating
• Ambient temperature range -25 to +45 °C
• Dimensions 104.2 x 83.5 x 22.5 mm
• Quick detection with LED display
• EEx e motor range compatibility
• Motor control and machine protection
• DIN rail mounting
• Screw mount with adapter (296-2382)

Functions within the Eaton EMT6 series:

All overload relay models have thermistor protection and auto reset.

297-2351 EMT6 24-240 V ac/dc
297-2373 EMT6-DB 24-240 V ac/dc plus manual/remote reset and fault memory
297-2395 EMT6-DBK plus undervoltage protection and short-circuit monitoring
297-2367 EMT6 (230V) 230 V ac
297-2389 EMT6-DB (230V) 230 V ac plus manual/remote reset and fault memory

What is a thermistor?

Thermistors are step-action temperature sensors, also referred to as PTC resistors or positive temperature coefficient resistors. Their resistance changes sharply when a defined temperature is exceeded. They are also commonly used for temperature monitoring of heating systems, heating circulation fans, in the windings of various sizes of transformers, for generator protection as well as for observing gaseous or liquid coolants, and temperature checking of non-electrical mechanical equipment.