NERC PRC-005 Compliance Support
eGridSync supports Transmission Owners, Generator Owners, and Distribution Providers with Protection System Maintenance Program (PSMP) development, implementation, evidence organization, and audit readiness aligned with PRC-005.
What is PRC-005?
PRC-005 is a NERC Reliability Standard focused on ensuring that Protection Systems, Automatic Reclosing, and Sudden Pressure Relaying are maintained, tested, and documented so they perform correctly when required.
The standard requires entities to establish and follow a Protection System Maintenance Program (PSMP). This program must be documented, implemented consistently, and provide evidence that maintenance activities are performed according to defined intervals and methods.
PRC-005 defines what types of equipment are included, how they should be maintained (time-based or performance-based methods), and how maintenance evidence must be retained. Maintenance is not optional and must follow defined methods and intervals to ensure grid reliability.
The standard does not dictate specific maintenance tasks or procedures. Instead, it requires each entity to define their program based on manufacturer recommendations, industry practices, and operational experience, while meeting minimum performance expectations.
Who Must Comply with PRC-005?
Transmission Owners (TO)
Entities owning transmission facilities and associated protection systems on the BES.
Generator Owners (GO)
Entities owning generation facilities and their protection schemes connected to the BES.
Distribution Providers (DP)
Entities operating distribution systems with facilities classified as part of the BES.
Important: Applicability depends on Bulk Electric System (BES) facility classification. Applicability can change when assets, configurations, or system impact changes. Determining what is in scope is a critical first step in compliance.
What is a Protection System Maintenance Program (PSMP)?
A PSMP is a formal program that defines, documents, and executes maintenance for all Protection System components subject to PRC-005. It must include:
Component Identification
Which Protection System components are subject to maintenance requirements
Maintenance Methods
How maintenance is performed (procedures, testing requirements)
Maintenance Intervals
How often maintenance is performed (time-based or performance-based)
Evidence & Records
How evidence is captured, stored, and retained for compliance demonstration
Maintenance Approaches
Time-Based Maintenance
Maintenance performed at fixed calendar intervals (e.g., every 6 years for microprocessor relays). Intervals are defined in the PSMP and cannot be exceeded. Straightforward to administer but may result in maintenance being performed more frequently than needed.
Performance-Based Maintenance
Allows interval extension based on demonstrated reliability of a device population. Requires continuous monitoring, documented performance criteria, and statistical analysis. If performance degrades, corrective action and interval adjustment are required. More complex to implement but can optimize resource allocation.
Combination Approaches
Many entities use time-based maintenance for most components while applying performance-based methods to specific device types with sufficient population data. This hybrid approach balances simplicity and optimization.
Equipment Types Covered by PRC-005
PRC-005 applies to various Protection System components. Each equipment type has different maintenance expectations based on technology and criticality:
Critical: Inventory completeness is essential. Missing components from your PSMP inventory is a common audit finding and potential violation.
What eGridSync Delivers for PRC-005 Compliance
Inputs Required for PRC-005 Implementation
To develop or audit your PSMP, eGridSync requires access to the following information:
| Item | Examples | Why Required |
|---|---|---|
| BES Facility List | Transmission lines, substations, generation plants with voltage levels | Establish PRC-005 applicability scope |
| One-Line Diagrams | Station single-lines showing protection zones and device locations | Identify all protection components and schemes |
| Protection Schemes | Line, transformer, bus, breaker failure, remedial action schemes | Define maintenance scope for each scheme type |
| Relay Information | Relay models, firmware versions, settings files, panel layouts | Determine appropriate maintenance intervals and methods |
| Maintenance Records | Historical test reports, calibration certificates, work orders | Assess current compliance status and gaps |
| Work Order System | Data fields, completion tracking, asset linkage capabilities | Design evidence capture and traceability processes |
| Evidence Storage | Document management systems, network drives, retention policies | Ensure audit-ready evidence accessibility |
| Battery Information | Manufacturer, model, installation date, capacity, configuration | Establish battery maintenance requirements per IEEE standards |
| Reclosing Details | Reclosing relay settings, schemes, applicability determinations | Determine which reclosing equipment is in scope |
| Sudden Pressure Relays | Transformer inventory with SPR devices and maintenance history | Include SPR testing in transformer maintenance intervals |
| Prior Audit Findings | Previous NERC audit results, mitigation plans, corrective actions | Address known deficiencies and prevent recurrence |
Common PRC-005 Compliance Failure Points
Understanding where entities commonly fail helps prevent violations and demonstrates program maturity:
Incomplete Protection Inventory
Failure to identify all Protection System components subject to PRC-005. This is especially common for newly commissioned assets, auxiliary relays, communication-assisted schemes, and components inherited through acquisitions or reconfigurations.
Missing or Late Maintenance
Maintenance performed after the maximum allowable interval has expired. Even a single day overdue constitutes a violation. Resource constraints, scheduling conflicts, and tracking errors are common causes.
Maintenance Performed But Not Provable
Work was completed but evidence is insufficient, lost, or not traceable to the specific device and interval. Generic test forms, missing signatures, incomplete data fields, and poor filing practices cause this issue.
Evidence Not Traceable to Specific Assets
Records exist but cannot be linked to individual protection components. Ambiguous asset identifiers, inconsistent naming conventions, and batch testing without device-level documentation lead to traceability failures.
Incorrect Application of Performance-Based Maintenance
Using performance-based intervals without proper monitoring, statistical justification, or documented performance criteria. Auditors scrutinize performance-based programs for technical rigor and defensibility.
Misunderstanding Automatic Reclosing Applicability
Including reclosing equipment that should be excluded, or excluding equipment that should be included. Applicability depends on whether reclosing is part of a fault isolation protection scheme.
Poor Battery Documentation
Station battery maintenance records lacking required testing (capacity, cell voltage, connection resistance) or performed at incorrect intervals. IEEE 450 and 1188 provide guidance, but entities must ensure PSMP compliance.
System Changes Not Reflected in PSMP
New facilities commissioned, protection schemes modified, or equipment replaced without updating the PSMP inventory and maintenance schedule. Change management processes must trigger PSMP review.
PRC-005 Audit & Evidence Expectations
Auditors evaluate PRC-005 compliance through documentation review and sampling. Understanding their expectations helps ensure audit readiness:
Auditors Look for Traceability, Not Just Activity
Demonstrating that maintenance occurred is insufficient. You must prove what was maintained, when, how (according to defined procedures), and who performed it. Each piece of evidence must be directly linkable to a specific Protection System component and its maintenance interval.
Evidence Must Show Four Key Elements
Sampling Readiness is Essential
Auditors select a sample of Protection System components and request evidence for those specific devices. You must be able to retrieve documentation quickly. Pre-audit sampling exercises help identify data quality issues and improve retrieval processes.
Documentation Consistency Matters More Than Volume
A concise, well-organized PSMP with consistent evidence practices is superior to extensive documentation with gaps and inconsistencies. Quality and defensibility outweigh quantity. Align your documented program with actual practices.
Frequently Asked Questions
What is PRC-005?
What is a Protection System Maintenance Program (PSMP)?
Who must comply with PRC-005?
What equipment is included under PRC-005?
What is time-based maintenance?
What is performance-based maintenance?
Can maintenance intervals be extended?
What evidence is required for PRC-005?
How long must PRC-005 evidence be retained?
What are common PRC-005 audit findings?
How are station batteries treated under PRC-005?
When is automatic reclosing included or excluded?
What happens if maintenance was missed?
How do we prepare for a PRC-005 audit?
How long does it take to build a compliant PSMP?
Official References
For complete standard requirements and technical guidelines, refer to official NERC resources:
Important: This page summarizes PRC-005 compliance concepts in original language for educational purposes. Always refer to the official NERC standard for authoritative requirements. eGridSync does not copy or reproduce NERC standard text.
Ready to Ensure PRC-005 Compliance?
For detailed engineering support, PSMP development, and PRC-005 compliance execution, contact eGridSync today.