Allen-Bradley 193-EC2BB E3 Plus 3-15 A Overload Relay

E3 Plus overload relay with 3-15 A range

When a motor circuit needs more than overload protection, the Allen-Bradley 193-EC2BB adds sensing and logic. It is an E3 Plus electronic overload relay with a 3 to 15 A current range, four inputs, two outputs and an adjustable trip class between 5 and 30, as printed on the Rockwell product page.

The E3 Plus (193-EC2 and EC3) differs from the basic 193-EC1 by having four inputs and two outputs instead of two and one, a PTC thermistor input for motor over-temperature protection and core-balance ground-fault sensing on the lower ratings, according to the 193-TD012 comparison table.

Catalog decode, partly: 193 is the bulletin and EC2 the E3 Plus platform; the 3 to 15 A range comes from the product page, and the option letters should be confirmed against the catalog.

Ground fault, thermistor and imbalance protection

The E3 Plus has an internal zero-sequence (core balance) ground-fault sensor on the lower current ratings, with trip and warning settings that begin at 20 mA. Rockwell notes clearly that this is equipment protection and not a ground-fault circuit interrupter for personnel protection.

A PTC thermistor input monitors motor winding temperature; the relay reacts when the thermistor resistance rises above the 3400 ohm response level. Current imbalance trip and warning levels are adjustable from 10 to 100%, with a trip delay of 0.1 to 25 seconds, and a second full-load setting supports two-speed motors.

Technical specifications

Control functions and DeviceLogix

The four 24V DC inputs and two relay outputs allow the relay to act as a small motor starter controller: start, stop, reverse or two-speed logic can run inside the relay using DeviceLogix function blocks, which keeps the motor running logic available even when the network is down.

Remote trip lets an external device such as a vibration switch trip the motor via a discrete input, and the DeviceNet data includes ground fault current and the trip snapshot. Rated operating voltage is 600V NEMA and 690 / 1000V IEC.

Ordering and documents

Specify 193-EC2BB with the contactor it will be mounted to and the network cable. The reference document is the 193-TD012A E3 and E3 Plus specification; the user manual is 193-UM002. The product page lists certifications as of 2026-07-16.

Seven Star LLC is an independent supplier in Muscat and quotes on request; please confirm every rating against the current Rockwell documents before ordering.

To quote 193-EC2BB, send the motor nameplate, the supply voltage, the control voltage, the starting method and the protective devices already in the panel. The device is only one part of a starter, and a short list of the other components lets us check the combination before ordering (E3 Plus overload relay, 3 to 15 A, 4 inputs, 2 outputs, ground fault, trip class 5-30).

Browse more items in Contactors & Overload Relays on our site, or send us the part number for a quotation.

How the 193-EC2BB Works

The 193-EC2BB measures the current in each motor phase and calculates the true RMS value, then feeds it into an electronic thermal model of the motor. The thermal capacity utilisation rises when the motor runs above the full-load current setting and falls as it cools; when it reaches 100%, the relay trips. The trip class sets the speed of this response: under the NEMA/UL convention, a class 10 relay trips within 10 seconds at 600% of the full-load setting, a class 20 within 20 seconds. Because the class is adjustable from 5 to 30, the same relay can protect a fast-tripping submersible pump or a slow-starting fan.

In addition to the thermal model, the E3 Plus compares the three phase currents for imbalance and phase loss, sums them through its internal core-balance sensor to detect earth leakage, and checks the motor PTC thermistor. Each function can be set to warn the controller first and trip only if the condition gets worse, which helps operators act before an unplanned stop.

Selection & Ordering Guide for the 193-EC2BB

• 193-EC1 – basic E3 with 2 inputs and 1 output, no ground-fault or thermistor input.
• 193-EC2 – E3 Plus with 4 inputs, 2 outputs, ground-fault sensing and PTC input; the 193-EC2BB covers 3 to 15 A.
• Select the current range so that the motor full-load current sits inside it.

The E3 and E3 Plus family has been discontinued by Rockwell Automation, and the E300 electronic overload relay is the migration path; for this rating, the 193-ESM-IG-30A-C23 E300 sensing module has been listed as the replacement. A like-for-like 193-EC2BB keeps existing wiring and DeviceNet configuration unchanged, while an E300 needs a new configuration and possibly a different communication module. Our team can help confirm the correct ordering code when you request a quote.

Installation & Maintenance

• Mount the relay to the matching contactor or a panel-mount adapter as described in the user manual.
• Set the full-load current from the motor nameplate, and for two-speed motors also set the second full-load current.
• Wire the PTC thermistor with a separate, screened cable kept away from the motor power conductors.
• Set the DeviceNet node address and baud rate before connecting to the network, and terminate the trunk at both ends.
• After a trip, read the trip snapshot and history to find the cause before resetting.

Typical Applications in Oman & the GCC

The 193-EC2BB is used in intelligent motor control centres for pumps, fans, compressors and conveyors in water and wastewater plants, desalination facilities, oil and gas processing and large building services. Ground-fault and thermistor protection are valuable on submersible and borehole pumps, where moisture ingress and overheating are common failure causes, and the DeviceNet data lets the control room monitor motor current and thermal state remotely.

Why Source from Seven Star LLC

Seven Star LLC supplies Allen-Bradley motor control components, including legacy items for existing systems, across Oman and the GCC. Send the 193-EC2BB catalog number and your motor data and request a quote; our team can help confirm the correct ordering code or the E300 replacement.