Product Introduction – ABB SACE Electronic Protection Technology

The ABB PR111/P LSI Circuit Breaker is an electronic protection unit developed for compatible SACE Emax low-voltage power circuit breakers. It combines three essential overcurrent protection functions in one compact electronic assembly, providing an effective solution for industrial electrical distribution applications.

In modern industrial facilities, electrical protection is essential to maintaining production continuity and protecting expensive equipment. Overloads and short-circuit faults can cause excessive heating, equipment damage, and unexpected production interruptions. An appropriately configured electronic trip unit helps detect these abnormal conditions and initiate circuit interruption when necessary.

The PR111/P LSI uses microprocessor-based technology to process current signals supplied by the circuit breaker's current transformers. Its long-time, short-time, and instantaneous protection functions allow engineers to configure different responses according to the electrical installation's operating requirements.

Another important characteristic is its self-powered design. The unit obtains the energy required for protection operation from the installed current transformers, eliminating the need for a separate external auxiliary supply for its protection functions.

For industrial maintenance teams, electrical contractors, and power distribution system integrators, the ABB PR111/P LSI remains a relevant component when maintaining compatible legacy SACE Emax circuit breaker installations.

Whether used for replacement, maintenance planning, or electrical distribution system servicing, selecting the correct PR111/P configuration is essential for maintaining reliable protection performance.

Technical Specifications – Product Information

Parameter	Specification
Brand	ABB
Model	PR111/P LSI
Product Type	Electronic Circuit Breaker Protection Unit
Product Series	SACE Emax
Protection Technology	Microprocessor-Based
Protection Functions	Long-Time, Short-Time, Instantaneous
Protection Configuration	LSI
Power Supply	Self-Powered by Current Transformers
Application	Low-Voltage Power Distribution
Standards	IEC 60947-2
Dimensions	362 × 65 × 195 mm
Weight	2.30 kg / 5.07 lb

Physical Specifications

Item	Value
Length	362 mm
Width	65 mm
Height	195 mm
Net Weight	2.30 kg
Weight in Pounds	5.07 lb

Note: The supplied physical measurements are presented as product data. Confirm the exact dimensions against the specific trip unit and mounting configuration before installation.

Recommended Related ABB Protection Units

For customers maintaining ABB SACE Emax circuit breakers, the following electronic protection units may also be relevant when evaluating replacement requirements or alternative protection configurations.

Model	Product Description
PR111/P LI	ABB Electronic Protection Unit – LI
PR111/P LSI	ABB Electronic Protection Unit – LSI
PR111/P LSIG	ABB Electronic Protection Unit – LSIG
PR112/P LSI	ABB Electronic Protection Unit – LSI
PR112/P LSIG	ABB Electronic Protection Unit – LSIG
PR113/P LSIG	ABB Electronic Protection Unit – LSIG

These models have different protection capabilities and compatibility requirements. They should not be regarded as interchangeable without checking the applicable ABB configuration.

Popular ABB SACE Emax Circuit Breaker Components

ABB SACE Emax equipment includes a range of low-voltage power circuit breakers and electronic protection accessories designed for industrial power distribution.

Model / Type	Product Description
PR111/P LI	Electronic Protection Unit
PR111/P LSI	Electronic Protection Unit
PR111/P LSIG	Electronic Protection Unit
PR112/P LSI	Electronic Protection Unit
PR112/P LSIG	Electronic Protection Unit
PR113/P LSIG	Electronic Protection Unit

The ABB PR111/P LSI is a practical choice for maintaining compatible SACE Emax circuit breaker protection systems. Its combination of long-time, short-time, and instantaneous protection makes it an important component in industrial low-voltage electrical distribution and circuit protection applications.

Applications – Reliable Protection for Industrial Power Distribution

The ABB PR111/P LSI is an electronic protection unit designed for use with compatible ABB SACE Emax low-voltage power circuit breakers. It provides coordinated overcurrent protection for industrial electrical distribution systems, helping safeguard equipment, feeders, and electrical installations against abnormal current conditions.

With three primary protection functions, the PR111/P LSI is suitable for applications where overload protection and short-circuit discrimination are important to power system safety.

Typical applications include:

Industrial Power Distribution: Protects electrical distribution circuits in manufacturing plants and industrial facilities.
Motor Control Systems: Supports circuit protection in installations supplying industrial motor control equipment.
Electrical Switchboards: Used in compatible ABB Emax circuit breaker assemblies.
Process Automation: Helps protect power distribution infrastructure supporting PLCs, drives, and other automation equipment.
Commercial Electrical Installations: Suitable for compatible low-voltage distribution systems.
Power System Maintenance: Provides an electronic protection solution for servicing and maintaining existing ABB circuit breaker installations.

Advantages – Intelligent Protection and Operational Reliability

Three-Level Overcurrent Protection

The PR111/P LSI combines long-time, short-time, and instantaneous protection functions. This arrangement helps address different overcurrent conditions within an electrical distribution system.

Microprocessor-Based Protection

Electronic protection technology allows the unit to monitor current conditions and apply configured protection thresholds, supporting more precise circuit protection than conventional thermal-magnetic arrangements.

Self-Powered Operation

The protection unit obtains its operating energy from the current transformers installed in the circuit breaker. Its protection functions do not require a separate external auxiliary power supply.

Adjustable Protection Parameters

The LSI protection settings can be configured to suit the electrical installation and coordination requirements, helping engineers establish an appropriate protection strategy.

Supports Selective Coordination

The adjustable short-time protection function helps engineers coordinate upstream and downstream circuit breakers, reducing unnecessary interruptions to unaffected sections of the electrical system.

Built for ABB SACE Emax Systems

Designed for compatible ABB Emax circuit breaker configurations, the PR111/P LSI offers a dedicated protection solution for industrial low-voltage distribution equipment.

Technical FAQs – Protection Functions and Application

Q1. What is the main function of the ABB PR111/P LSI?

The PR111/P LSI is an electronic overcurrent protection unit designed to monitor electrical current and initiate circuit breaker tripping when configured protection thresholds are exceeded.

Q2. What does LSI stand for?

LSI represents three protection functions:

L – Long-Time Protection: Protects against overloads using an inverse-time delay.
S – Short-Time Protection: Provides protection against short circuits with an adjustable time delay.
I – Instantaneous Protection: Trips the circuit breaker rapidly when current reaches the configured instantaneous threshold.

Q3. Does the PR111/P LSI provide ground-fault protection?

The standard LSI version does not include the dedicated adjustable ground-fault protection function provided by the LSIG version. The correct trip unit should be selected according to the installation's protection requirements.

Q4. Is the PR111/P LSI self-powered?

Yes. The protection unit obtains its operating energy from the current transformers installed in the circuit breaker. An independent external auxiliary power supply is not required for its protection functions.

Q5. Can the protection settings be adjusted?

Yes. The protection parameters can be configured using the unit's designated adjustment switches. Settings should be selected according to the circuit characteristics and protection coordination study.

Q6. Which circuit breaker platforms support the PR111/P LSI?

The PR111/P is designed for compatible ABB SACE Emax circuit breakers. The exact breaker frame, rated current, pole configuration, and installation arrangement must be verified before selection.

Q7. What happens when an overload occurs?

The long-time protection function monitors the overcurrent condition and applies an inverse-time tripping characteristic. This allows the breaker to respond according to the magnitude and duration of the overload.

Q8. How does short-time protection improve system coordination?

The adjustable short-time delay allows downstream protective devices an opportunity to clear certain faults first, helping reduce unnecessary interruption of the wider electrical distribution system.

Q9. What should be checked if the circuit breaker trips unexpectedly?

Inspect the protection settings, current transformer signals, electrical load conditions, and trip indication. Determine whether the event resulted from an actual overload, short circuit, incorrect setting, or another system issue before resetting the breaker.

Q10. Can the PR111/P LSI be replaced directly with a PR112/P or PR113/P?

Not automatically. Different electronic trip units have different protection functions and hardware requirements. Any replacement must follow ABB's approved compatibility and retrofit requirements.

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