Overload Relays

Catalogs > Industrial Controls Catalog > Motor Control, IEC > Overload Relays > Bulletin 193-EC E3 and E3 Plus Solid-State Overload Relays

Bulletin 193-EC E3 and E3 Plus Solid-State Overload Relays

Introduction Standards Compliance and Certifications Product Overview Catalog Number Explanation
Product Selection Accessories Specifications Approximate Dimensions
Product Overview

The E3 Overload Relay is available in two configurations: the E3 and E3 Plus. The following table illustrates the functional differences between the two:

Feature E3 E3 Plus
Inputs¬  2 4
Outputs 1 2
Thermistor Input No Yes
Ground Fault Protection No Yes
DeviceLogix No Yes
  
¬ Inputs are rated 24V DC.

Thermal Overload

Thermal Utilization

The E3 Overload Relay provides overload protection through true RMS current measurement of the individual phase currents of the connected motor. Based on this information, a thermal model that simulates the actual heating of the motor is calculated. Percent of thermal capacity utilization (%TCU) reports this calculated value and can be read via the DeviceNet network. An overload trip occurs when the value reaches 100%.

Adjustable Settings

Thermal overload protection setup is accomplished simply by programming the motor’s full load current rating (FLA) and the desired trip class (5…30). Programming of the actual values through software programming ensures the accuracy of the protection.

Thermal Memory

The E3 Overload Relay includes a thermal memory circuit designed to approximate the thermal decay for a trip class 30 setting. This means that the thermal model of the connected motor is maintained at all times, even if the supply power is removed.

Reset Modes

Flexibility is afforded the end-user in the ability to select between manual and automatic reset for an overload trip, allowing for broad application. The point of reset is user adjustable from 1…100% TCU.

Time to Trip

During an overload condition, the E3 Overload Relay provides an estimated time to trip that is accessible via the DeviceNet network. This allows corrective action to be taken so that production may continue uninterrupted.

Time to Reset

Following an overload trip, the E3 Overload Relay will not reset until the calculated percentage of thermal capacity utilization falls below the reset level. As this value decays, the time to reset, which is accessible via the DeviceNet network, is reported.

Thermal Warning

The E3 Overload Relay provides the capability to alert in the event of an impending overload trip. A thermal warning bit is set in the Warning Status word when the calculated percentage of thermal capacity utilization exceeds the programmed thermal warning level, which has a setting range of 0…100% TCU.

Two-Speed Protection

The E3 Plus Overload Relay offers a second FLA setting for 2-speed motor protection. What used to require two separate overload relays, one for each set of motor windings, can now be accomplished with one device. Improved protection is delivered as thermal utilization is maintained in one device during operation in both speeds.

Phase Loss

The E3 Overload Relay offers configurable phase loss protection in allowing the installer to enable or disable the function plus set a time delay setting, adjustable from 0.1…25.0 seconds. The trip level is factory-set at a current imbalance measurement of 100%.

Ground (Earth) Fault

The E3 Plus Overload Relay incorporates zero sequence (core balance) sensing into its design through the 90 A rating for low level (arcing) ground fault detection. Trip and warning settings are adjustable from 20 mA…5.0 A. For devices rated greater than 90 A and for ground fault detection less than 1.0 A, the external core balance current transformer accessory is required. Class I protection is provided as defined by UL1053. Series B or later devices provide a trip inhibit setting, offering flexibility to prevent tripping when the ground fault current magnitude exceeds 10 A. This can be useful to guard against opening of the controller when the fault current could potentially exceed the controller's interrupting capacity rating. Note: The E3 Plus Overload Relay is not a Ground Fault Circuit-Interrupter for personnel protection as defined in article 100 of the U.S. National Electric Code.

Stall

Stall is defined as 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 motor overheating as current draw is in excess of the motor’s full load current rating.
The E3 Overload Relay provides user-adjustable stall protection. The trip setting has a range of 100…600% FLA, and the enable time is adjustable up to 250 seconds.

Jam (Overcurrent)

The E3 Overload Relay can respond quickly to take a motor off-line in the event of a mechanical jam, thereby reducing the potential for damage to the motor and the power transmission components.
Trip adjustments include a trip setting adjustable from 50…600% FLA and a trip delay time with a range of 0.1…25.0 seconds. A separate warning setting is adjustable from 50…600% FLA.

Underload (Undercurrent)

A sudden drop in motor current can signal conditions such as


For these instances, rapid fault detection can help minimize damage and aid in reducing production downtime.

Additionally, monitoring for an underload event can provide enhanced protection for motors that are coded by the medium handled (e.g., submersible pumps that pump water). Such motors can become overheated despite being underloaded. This can result from an absence or an insufficient amount of the medium (due to clogged filters, closed valves, etc.).

The E3 Overload Relay offers underload trip and warning settings adjustable from 10…100% FLA. The trip function also includes a trip delay time with a range of 0.1…25.0 seconds.

Over-temperature Protection

The E3 Plus Overload Relay provides motor over-temperature protection with the added provisions for terminating and monitoring of stator windingembedded positive temperature coefficient (PTC) thermistors. PTC thermistors are semiconductors that exhibit a large increase in resistance when the rated response temperature is exceeded. When the monitored PTC thermistor resistance exceeds the response level of the E3 Plus Overload Relay (3400 W), it can be set to trip immediately or programmed to set the PTC bit of the Warning Status word.

Current Imbalance (Asymmetry)

The E3 Plus Overload Relay offers current imbalance trip and warning settings adjustable from 10…100%. The trip function also includes a trip delay time with a range of 0.1…25.0 seconds.

Remote Trip

The remote trip function allows an external device such as a vibration sensor to induce the E3 Overload Relay to trip. External device relay contacts are wired to the E3 Overload Relay discrete iputs. The discrete inputs are configurable with an option for assigning the remote trip function.

Current Monitoring Functions

The E3 Overload Relay allows the user to monitor the following operational data over the DeviceNet network:


Diagnostic Functions

The E3 Overload Relay allows the user to monitor the following diagnostic information over the DeviceNet network:


Status Indicators

The E3 Overload Relay provides the following LED indicators:

Network Status: This green/red LED indicates the status of the network connection.

TRIP/WARN: This LED flashes an amber code under a warning condition and a red code when tripped.

OUT A and B: These amber LEDs illuminate when the output contacts are commanded closed.

IN 1– 4: These amber LEDs illuminate when the user-connected device contact is closed.

Note: IN 3 and 4 and OUT B are available only on the E3 Plus Overload Relay.

Inputs/Outputs

Inputs allow the connection of such devices as contactor and disconnect auxiliary contacts, pilot devices, limit switches and float switches. Input status can be monitored via the network and mapped to a controller’s input image table. Inputs are rated 24V DC and are current sinking. Power for the inputs is sourced from the DeviceNet network connection with convenient customer terminations at control terminals 5 and 6. Relay contact outputs can be controlled via the network or DeviceLogix function blocks for performing such tasks as contactor operation.

Test/Reset Button

The Test/Reset button located on the front of the E3 Overload Relay allows the user to perform the following:
Test: The trip relay contact will open if the E3 Overload Relay is in an untripped condition and the Test/Reset button is pressed for 2 seconds or longer.
Reset: The trip relay contact will close if the E3 Overload Relay is in a tripped condition, supply voltage is present, and the Test/Reset button is pressed.

Single/Three-Phase Operation

The E3 Overload Relay can be applied to three-phase as well as single-phase applications. A programming parameter is provided for selection between single- and three-phase operation. Straight-through wiring is afforded in both cases.

DeviceNet Communications

The E3 Overload Relay is a Group 2 “slave only” device and supports the following:


For more information on operation and maintenance of this product, please reference the user manual, publication 193-UM002_-EN-P.

DeviceLogix

The E3 Plus offers increased control flexibility with DeviceLogix capabilities. Using RSNetWorx for DeviceNet (version 3.0 or later), function block programs can be configured and saved to an E3 Plus Overload Relay to operate single logic routines. The function blocks are programmed using standard Boolean operators such as AND, OR, XOR, and NOT, plus timers, counters, and latches. In addition to allowing the use of the integral discrete inputs, protection functions can also be used as inputs to trigger outputs. For example, the Ground Fault Protection function could be used to control Output A of the E3 Plus Overload Relay for operation of a circuit breaker short-trip mechanism.

DeviceNet™ Configuration Terminal

The DeviceNet Configuration Terminal (Cat. No. 193-DNCT) is a handheld device that can be used to commission, configure, program, and monitor devices on your DeviceNet network. The 193-DNCT allows you to increase productivity and ease troubleshooting with easy access to information and diagnostics of your system.

Network Who

The 193-DNCT can be used with any DeviceNet device and has DeviceLogix, metering, graphing, and auto-display capabilities which can help ease troubleshooting by commissioning devices online through your network. The terminal searches for all devices on the network and provides device address, device name, and status of a device.

Monitoring & Editing

The DeviceNet Configuration Terminal can be used to upload, store, and download device configurations and DeviceLogix™ programs for DeviceNet devices via your network. Easily replace and reconfigure scan lists of DeviceNet scanners (minus the Automatic Device Replacement configuration). Parameters can be accessed as either groups or as a numbered list of all parameters, and they can be monitored and edited.

Diagnostics

Ease troubleshooting using the DeviceNet Configuration Terminal. The 193-DNCT can present DeviceNet diagnostics, network utilization, and network statistics are available including baud rate, bus voltage, percentage of bus loading, and CAN errors.

DeviceLogix

The terminal allows you to enable, monitor, edit, or delete DeviceLogix programs.

AC Input Interface Module Accessory

The AC Input Interface Module conveniently allows the E3 overload relay to be retrofitted or applied in new applications that require 110/120V AC control circuitry. This new accessory simply plugs into the E3 overload relay’s existing input terminals, optimizing panel space utilization. The module accepts termination of up to four external devices, making it compatible with the E3 and E3 Plus versions of the E3 overload relay. Optical isolation is provided between the AC input wiring and the E3’s internal 24V circuitry.