User Manual

34 Rockwell Automation Publication 193-UM002I-EN-P - December 2011

Chapter 2 Installation & Wiring

Typical Motor Connections

Three-Phase Direct On-Line (DOL) & Single-Phase Full Voltage

The following wiring diagram illustrates the E3 Overload Relay typical motor

connections in a three-phase DOL and Single-Phase Full Voltage applications.

Figure 13 - Wiring Diagram, Three-Phase DOL & Single-Phase Full Voltage

External Line Current

Transformer Application

193-EC_ZZ E3 and E3 Plus Overload Relays are designed for use with separately

mounted, customer-supplied, line current transformers (CTs) as required in

higher-current applications. The FLA setting range is 9…5000 A for these units

with a legal setting range per current transformer. CT Ratio, Parameter 78, is

provided for setting the current transformer ratio to be installed.

Specifications

The 193-EC_ZZ Overload Relays are intended for use with CTs having a

secondary current rating of 5 A. The installer shall (1) provide one CT for each

motor phase and shall (2) connect the CT’s secondary leads to the appropriate E3

ATTENTION: When working on energized circuits, DO NOT rely on

voltage and current information provided by the E3 and E3 Plus Overload

Relay for personal safety. Always use a portable voltage or current

measurement device to measure the signal locally.

IMPORTANT

Single/Three Ph, Parameter 27, should be set to single-phase.

IMPORTANT

Traditional single-phase wiring connecting T2 to L3 will result in a vector

imbalance of current flowing through the E3 Plus Overload Relay. This

will result in inaccurate ground fault reporting and protection.

2/T1

4/T2

6/T3

Three-Phase Direct-On-Line

Single-Phase Full-Voltage

E3/E3 Plus

L1 L2

Voltage Input Module

(For 193/592-EC5 only)