PRC-005-6: Protection System, Automatic Reclosing, and Sudden Pressure Relaying Maintenance

NERC Standard PRC-005-6 requires that protective devices are regularly maintained and tested.  Enforceable across nearly all interconnected high-voltage systems in the U.S., much of Canada, and parts of Mexico, the standard calls for all registered Transmission Owners (TOs), Generator Owners (GOs), and Distribution Providers (DPs) to establish a documented Protection System Maintenance Program (PSMP).

If a component detects or isolates BES faults or restores lines automatically, it likely falls under PRC-005. Specific components that fall under PRC-005 include: 

• Protective Relays — whether electromechanical, solid-state, or microprocessor-based, 
• Station DC Supply components that power relays and breaker trip coils,  
• Protective Communication Systems, such as teleprotection links, ,  
• Voltage and Current Sensing Devices (CTs and PTs/VTs),  
• Control Circuitry, including wires and auxiliary devices that transmit trip signals (e.g., lockout relays/86 devices), is part of the Protection System  
• Under-Frequency and Under-Voltage Load Shedding (UFLS/UVLS) systems 
• Remedial Action Schemes (RAS, formerly SPS) 
• Components like Automatic Reclosing and Sudden Pressure Relays 

Though generally reliable, these devices require inspection to confirm connections are intact, and circuits are not improperly grounded.  

All covered components must be maintained per defined tasks and maximum intervals, unless the entity uses performance-based maintenance, which evaluates actual performance over time to determine need. This method is less common and has specific conditions for use. 

NERC compliance auditors will expect evidence that all protection functions capable of tripping BES elements are included. This is typically verified by cross-checking PRC-005 asset lists against one-lines and relay setting databases. Missing devices that appear on drawings but not in the program can trigger a Potential Non-Compliance (PNC) unless a valid exclusion is documented. A clear relay exclusion list helps justify omissions that could be costly if not properly documented. 

PRC-005 does not cover cybersecurity or EMS systems (e.g., firmware or SCADA RTUs), which fall under CIP. While some entities over-include devices to be cautious, this can strain resources — your focus should remain on relevant components, with documented rationale for exclusions.

Due to its broad applicability and varying maintenance intervals PRC-005 has been one of the most frequently violated NERC Standards since its inception. While most violations haven’t posed immediate grid risks or resulted in large penalties, some recent cases have been significant, including a $141K fine in SERC in 2024 and a $400K penalty in RF between 2018–2019 for multiple violations. Many entities now have more mature programs, and violations are currently on the decline, but minor issues remain common. 

EPE can help you avoid these costly potential pitfalls by developing a detailed compliance tracker that ensures all applicable devices are identified and maintenance intervals are met. To find out more about how we can support your project, contact our experts using the form below.