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NERC PRC-005 requirements for battery maintenance when no monitoring

Table 1-4(a)

Protection System Station dc Supply Using Vented Lead-Acid (VLA) Batteries

Maximum

Interval

 Maintenance Activities
4 Calendar Months Verify:

  • Station dc supply voltage

Inspect:

  • Electrolyte level
  • For unintentional grounds
18 Calendar Months Verify:

  • Float voltage of battery charger
  • Battery continuity
  • Battery terminal connection resistance
  • Battery intercell or unit-to-unit connection resistance

Inspect:

  • Cell condition of all individual battery cells where cells are visible – or measure battery cell/unit internal ohmic values where the cells are not visible
  • Physical condition of battery rack
18 Calendar Months

-or-

6 Calendar Years

 Verify that the station battery can perform as manufactured by evaluating cell/unit measurements indicative of battery performance (e.g. internal ohmic values or float current) against the station battery baseline.

-or-

Verify that the station battery can perform as manufactured by conducting a performance or modified performance capacity test of the entire battery bank.

Table 1-4(b)

Protection System Station dc Supply Using Valve-Regulated Lead-Acid (VRLA) Batteries

Maximum

Interval

 Maintenance Activities
4 Calendar Months Verify:

  • Station dc supply voltage

Inspect:

  • For unintentional grounds
6 Calendar Months Inspect:

  • Condition of all individual units by measuring battery cell/unit internal ohmic values.
18 Calendar Months Verify:

  • Float voltage of battery charger
  • Battery continuity
  • Battery terminal connection resistance
  • Battery intercell or unit-to-unit connection resistance

Inspect:

  • Physical condition of battery rack
6 Calendar Months

-or-

3 Calendar Years

 Verify that the station battery can perform as manufactured by evaluating cell/unit measurements indicative of battery performance (e.g. internal ohmic values or float current) against the station battery baseline.

-or-

Verify that the station battery can perform as manufactured by conducting a performance or modified performance capacity test of the entire battery bank.

Table 1-4(C)

Protection System Station dc Supply Using Nickel-Cadmium (NiCad) Batteries

Maximum

Interval

 Maintenance Activities
4 Calendar Months Verify:

  • Station dc supply voltage

Inspect:

  • Electrolyte level
  • For unintentional grounds
18 Calendar Months Verify:

  • Float voltage of battery charger
  • Battery continuity
  • Battery terminal connection resistance
  • Battery intercell or unit-to-unit connection resistance

Inspect:

  • Cell condition of all individual battery cells.
  • Physical condition of battery rack
6 Calendar Years Verify that the station battery can perform as manufactured by conducting a performance or modified performance capacity test of the entire battery bank.

NERC PRC-005 requirements for battery maintenance when effective monitoring is implemented

Monitoring Parameters

BatteryDAQ
Sentry

 Component Attributes Maintenance Activities
String Voltage

Yes

 Any station dc supply with high and low voltage monitoring and alarming of the battery charger voltage to detect charger over-voltage and charger failure. No periodic verification of station dc supply voltage is required.
Electrolyte Level

In person

 Electrolyte level monitoring is not a solution to maintain optimal level. Periodic inspection of the electrolyte level for each cell is required.
Ground Fault

Yes

 Any station dc supply with unintentional dc ground monitoring and alarming.

Ground Fault Detection with Charger or GF-100

 No periodic inspection of unintentional dc grounds is required.
Cell Voltage

Yes

 Any station dc supply with charger float voltage monitoring and alarming to ensure correct float voltage is being applied on the station dc supply. No periodic verification of float voltage of battery charger is required.
String Connection

Yes

 Any battery based station dc supply with monitoring and alarming of battery string continuity. No periodic verification of the battery continuity is required.
Inter-cell Resistance

Yes

 Any battery based station dc supply with monitoring and alarming of the inter-cell and/or terminal connection detail resistance of the entire battery. No periodic verification of the intercell and terminal connection resistance is required.
Internal Resistance

Or float current

Yes

 Any Valve Regulated Lead-Acid (VRLA) or Vented Lead-Acid (VLA) station battery with internal ohmic value or float current monitoring and alarming, and evaluating present values relative to baseline internal ohmic values for every cell/unit. No periodic evaluation relative to baseline of battery cell/unit measurements indicative of battery performance is required to verify the station battery can perform as manufactured.
Internal Resistance

Yes

 Any Valve Regulated Lead-Acid (VRLA) or Vented Lead- Acid (VLA) station battery with monitoring and alarming of each cell/unit internal ohmic value. No periodic inspection of the condition of all individual units by measuring battery cell/unit internal ohmic values of a station VRLA or Vented Lead-Acid (VLA) battery is required.