Prc-011-0

Standard PRC-011-0 — UVLS System Maintenance and Testing
A. Introduction
1.

Title:

Undervoltage Load Shedding System Maintenance and Testing

2.

Number:

PRC-011-0

3.

Purpose:
Provide system preservation measures in an attempt to prevent system voltage
collapse or voltage instability by implementing an Undervoltage Load Shedding (UVLS)
program.

4.

Applicability:
4.1. Transmission Owner that owns a UVLS system
4.2. Distribution Provider that owns a UVLS system

5.

Effective Date:

April 1, 2005

B. Requirements
R1.

The Transmission Owner and Distribution Provider that owns a UVLS system shall have a
UVLS equipment maintenance and testing program in place. This program shall include:
R1.1.

The UVLS system identification which shall include but is not limited to:
R1.1.1. Relays.
R1.1.2. Instrument transformers.
R1.1.3. Communications systems, where appropriate.
R1.1.4. Batteries.

R2.

R1.2.

Documentation of maintenance and testing intervals and their basis.

R1.3.

Summary of testing procedure.

R1.4.

Schedule for system testing.

R1.5.

Schedule for system maintenance.

R1.6.

Date last tested/maintained.

The Transmission Owner and Distribution Provider that owns a UVLS system shall provide
documentation of its UVLS equipment maintenance and testing program and the
implementation of that UVLS equipment maintenance and testing program to its Regional
Reliability Organization and NERC on request (within 30 calendar days).

C. Measures
M1. Each Transmission Owner and Distribution Provider that owns a UVLS system shall have
documentation that its UVLS equipment maintenance and testing program conforms with
Reliability Standard PRC-011-0_R1.
M2. Each Transmission Owner and Distribution Provider that owns a UVLS system shall have
evidence it provided documentation of its UVLS equipment maintenance and testing program
and the implementation of that UVLS equipment maintenance and testing program as specified
in Reliability Standard PRC-011-0_R2.
D. Compliance
1.

Compliance Monitoring Process

Adopted by NERC Board of Trustees: February 8, 2005
Effective Date: April 1, 2005

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Standard PRC-011-0 — UVLS System Maintenance and Testing
1.1. Compliance Monitoring Responsibility
Compliance Monitor: Regional Reliability Organization.
1.2. Compliance Monitoring Period and Reset Timeframe
On request (30 calendar days).
1.3. Data Retention
None specified.
1.4. Additional Compliance Information
None.
2.

Levels of Non-Compliance
2.1. Level 1:
Documentation of the maintenance and testing program was complete, but
records indicate implementation was not on schedule.
2.2. Level 2:
Documentation of the maintenance and testing program was incomplete, but
records indicate implementation was on schedule.
2.3. Level 3:
Documentation of the maintenance and testing program was incomplete, and
records indicate implementation was not on schedule.
2.4. Level 4:
Documentation of the maintenance and testing program, or its
implementation, was not provided.

E. Regional Differences
1.

None identified.

Version History
Version

Date

Action

Change Tracking

0

April 1, 2005

Effective Date

New

0

October 12, 2005

Level 2 Non-Compliance: Changed
“incomplete” to “complete” and inserted
“not” between “was” and “on.”

Errata

Adopted by NERC Board of Trustees: February 8, 2005
Effective Date: April 1, 2005

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