Based RMS current measurement, the overload relay calculates a thermal model that simulates the actual heating of the motor. Percent of thermal capacity

Thermal Utilization

utilization (%TCU) reports this calculated value. An overload trip occurs when the value reaches 100%.

Configure thermal overload protection by programming the motor's full load current (FLC) rating and the desired trip class (5...30). Programming the actual

Adjustable Settings

values via software ensures the accuracy of the protection.

A thermal memory circuit approximates the thermal decay for a Trip Class 20 setting. This means that the thermal model of the connected motor is maintained

Thermal Memory

at all times, even if the supply power is removed.

Reset Modes

You can select between manual and automatic reset for an overload trip. The point of reset is adjustable from 1...100% TCU.

Time to Trip

During an overload condition, an estimated time to trip is calculated.

Following an overload trip, a reset does not occur until the calculated percentage of thermal capacity utilization falls below the reset level. As this value decays,

Time to Reset

the time to reset adjusts accordingly.

A thermal warning bit is set when the calculated percentage of thermal capacity utilization exceeds the programmed thermal warning level, which has a setting

Thermal Warning

range of 0...100% TCU.

There is a second FLA setting for 2-speed motor protection. What used to require two separate overload relays - one for each set of motor windings - is now

Two-Speed Protection

accomplished with one device.

Feature

Description

The overload relay can take a motor off-line in the event of a mechanical jam. Trip adjustments include a trip setting adjustable from 50...600% FLA and a trip

Jam (Overcurrent)

delay time with a range of 0.1...25.0 seconds. A separate warning setting is adjustable from 50...600% FLA.

A sudden drop in motor current can signal conditions such as:

• Pump cavitation

• Tool breakage

Underload (Undercurrent)

• Belt breakage

Monitoring for an underload event can provide enhanced protection for motors. The underload trip and warning settings are adjustable from 10...100% FLA. The

trip function also includes a trip delay time with a range of 0.1...25.0 seconds.

Current imbalance trip and warning settings are adjustable from 10...100%. The trip function also includes a trip delay time with a range of 0.1...25.0

Current Imbalance (Asymmetry)

seconds.

Stall is a condition where the motor is not able to reach full-speed operation in the appropriate amount of time required by the application. This can result in

Stall

motor overheating, as current draw is in excess of the motor's full load current rating. The adjustable stall protection has a trip setting with a range of

100...600% FLA, and the enable time is adjustable up to 250 seconds.

Configurable phase loss protection lets you enable or disable the function plus set a time delay setting, adjustable from 0.1...25.0 seconds. The trip level is

Phase Loss

factory set at a current imbalance measurement of 100%.

• Reversing starter

• Wye/Delta (Star/Delta) starter

• Two-speed starter

• Monitoring device