PCR

PCR

Polarization Cell Replacement

The Polarization Cell Replacement (PCR) is a solid-state device designed to simultaneously provide DC decoupling and AC continuity/grounding when used with cathodically protected structures, such as pipelines, tanks, grounding systems, and cable casings.  Commonly used to decouple electric equipment from grounding systems, for AC Mitigation projects, or other isolation and grounding applications, the PCR provides safety grounding while also isolating your cathodically protected structure, improving CP system performance. With a higher blocking voltage than polarization cells and other technologies, the PCR eliminates the need for placing devices in series. Additionally,high AC fault current and lightning surge current ratings provide long-life with a low risk of product failure making it an ideal solution. The PCR has been used by customers around the world and is the original solid-state decoupler offered to the industry.

Features and Characteristics

  • Solid-State, Maintenance Free Operation
  • Wide Range of AC Fault Ratings Suitable For Many Applications
  • Higher Blocking Voltage than Polarization Cells
  • UL and C-UL Listed for Grounding Electrical Equipment
  • UL, C-UL Listed for Class I, Division 2 Locations
  • Certified by UL/DEMKO for Meeting ATEX Directive for Zone 2; CE Marked
  • Certified by UL for IECEx Zone 2 locations
  • Available in Submersible Version
  • EAC Certified Products Available - Learn More Here
    Certifications
 
      
  • threshold voltage
  • -3/+1V (standard)
  • -2/+2V (optional)
  • -4/+1V (optional)*
  • -6/+1V (optional)*
  • * Available with 3.7kA and 5kA fault current ratings. Not compatible with 80A models.
  • ac steady-state current (amperes - rms) 50/60Hz
  • 45A (standard)
  • 80A (optional)
  • lightning surge current
  • 100kA crest (8 x 20 µs waveform)
  • environmental rating
  • NEMA 4X (standard)
  • NEMA 6P (optional)
  • hazardous (classified) areas
  • ANSI/ISA 12.12.01, CSA C22.2 No.213-M1987 (R2008): Class I, Division 2, Groups A, B, C, D
  • ATEX: EN60079-0:2012, EN60079-15:2010 - Zone 2, Group IIC
  • IECEx: IEC60079-0: 6th Ed., IEC60079-15: 4th Ed. - Zone 2, Group IIC
  • EAC: GOST R IEC 60079-15-2010, GOST R IEC 60079-0-2011
  • third-party listings and approvals
  • Underwriter's Laboratories (UL)
  • Underwriter's Laboratories - Canada (C-UL)
  • UL/DEMKO
  • NANIO-CCVE
See full Certifications/Listings for the PCR
AC Fault Current (amperes-rms) 60 Hz
Model 1 cycle 3 cycles 10 cycles 30 cycles
PCR-3.7KA 6,500 5,000 4,200 3,700
PCR-5KA 8,800 6,800 5,700 5,000
PCR-10KA 20,000 15,000 12,000 10,000
PCR-15KA 35,000 27,000 21,000 15,000
AC Fault Current (amperes-rms) 50 Hz
Model 1 cycle 3 cycles 10 cycles 30 cycles
PCR-3.7KA 6,500 5,000 4,200 3,700
PCR-5KA 8,800 6,800 5,700 5,000
PCR-10KA 19,000 14,000 11,000 9,000
PCR-15KA 33,000 25,000 19,000 14,000
View Model Number Description Chart

The PCR has been tested by Nationally Recognized Testing Laboratories (NRTLs) for compliance to independent standards in its operation, ratings, and construction. This includes compliance to standards for:

SAFETY GROUNDING

UL (United States) and C-UL (Canada) listing for:

  • Providing an "effective ground-fault current path" as defined in NFPA 70 (US National Electrical Code - NEC), Article 250.2, and required in 250.4(A)(5)
  • Likewise, per Canadian Standards Association CSA C22.1-12 Canadian Electrical Code, Article 10-500
  • Providing over-voltage protection in accordance with the applicable requirements of ANSI C62.11

BLOCKING CATHODIC PROTECTION CURRENT

  • Providing DC isolation of objectionable DC ground currents in grounding conductors as defined in NFPA 70, Article 250.6(E), and in CSA C22.1-12 Article 10-806

HAZARDOUS LOCATION USE

  • The PCR has been certified for use in Class I, Division 2, Groups A, B, C, D hazardous locations by UL, C-UL according to:
  • NFPA 70 (U.S. National Electrical Code) sections 500-505
  • ANSI/ISA 12.12.01-2011
  • CSA C22.2 No.213-M1987 (R2008)

The PCR has been certified to the ATEX Directive 94/9/EC for use in Zone 2, Group IIC hazardous locations by UL/DEMKO, according to:

  • EN60079-0: 2012 and EN60079-15:2010

The PCR has been certified to IECEx for use in Zone 2, Group IIC hazardous locations by UL, according to:

  • IEC60079-0: 6th Ed and IEC60079-15: 4th Ed

The PCR has been certified to the EAC requirements within TP TC 012/2011 for Zone Class 2 hazardous locations by NANIO-CCVE, according to:

  • GOST R IEC 60079-15-2010, GOST R IEC 60079-0-2011
PCR Model Numbers

Literature:
PCR - One Page Datasheet
PCR - Technical Literature
PCR - Installation Instructions

Support Documents:
Certifications & Listings
Competitive Comparisons
PCR - Declaration of Conformity

Application Assistance:
Insulated Joint Protection
AC Voltage Mitigation
Decoupling Electric Equipment Grounding Systems
Decoupling From Utility Grounding Systems

The PCR has been tested by Nationally Recognized Testing Laboratories (NRTLs) for compliance to independent standards in its operation, ratings, and construction. This includes compliance to standards for:

Safety Grounding

UL (United States) and C-UL (Canada) listing for:

  • Providing an "effective ground-fault current path" as defined in NFPA 70 (US National Electrical Code - NEC), Article 250.2, and required in 250.4 (A)(5)
  • Likewise, per Canadian Standards Association CSA C22.2 No. 0.4-M1982 (R2009), using Canadian Electrical Code Part I, section 10-500 as a guide.
  • Providing over-voltage protection in accordance with the applicable requirements of ANSI C62.11

Blocking Cathodic Protection Current

  • Providing DC isolation of objectionable DC ground currents from cathodic protection systems as defined in NFPA 70, Article 250.6(E)

HAZARDOUS LOCATION USE

The PCR has been certified for use in Class I, Division 2, Groups A, B, C, D hazardous locations by UL, C-UL, according to:

  • U.S. National Electrical Code sections 500-505
  • ANSI/ISA 12.12.01
  • CSA C22.2 No.213-M1987 (R2008)

The PCR has been certified to the ATEX Directive 94/9/EC for use in Zone 2, Group IIC hazardous locations by DEMKO, according to EN 50021.

Liquid Filled

Comparison of Dairyland PCR to liquid-filled polarization cells

Polarization cell: The polarization cell is an electrochemical switch comprised of pairs of stainless steel or nickel plates immersed in a solution of potassium hydroxide. It responds to DC current by polarizing the plates and reducing the flow of DC current. This occurs up to the threshold of about 1.2V, after which it effectively becomes a dead short. AC current can pass through the device. The electrolyte usually has an oil film on the top to prevent the evaporation. This electrolyte is a hazardous material, with issues of safety, disposal, and environmental concerns. Regular maintenance of the fluid level is needed, especially under conditions where high AC steady-state induced current is present, which can cause the fluid level to be reduced. Fluid level must be maintained to provide the nameplated AC fault current rating, otherwise the surface area for conduction is reduced. On some interval, the fluid is replaced with new electrolyte.

Dairyland PCR: The PCR is a solid-state device which provides DC isolation and AC grounding, up to a threshold of about 3V. It has low AC impedance, allowing induced AC current to be shunted to ground, while providing a high impedance to DC current flow. The solid-state design results in very consistent device characteristics. The device was introduced in 1994 and is used on a wide-spread basis as a replacement for polarization cells. An extensive user base has applied the PCR to pipeline systems, tanks, power cable casings, and separation of grounding systems, for AC grounding and DC isolation of cathodically protected structures. Applications include AC mitigation, lightning over-voltage protection, AC fault conduction, stray current blocking, and grounding electrical equipment that are tied to CP systems. On this last application, the PCR is the only UL listed device for providing an effective grounding path for electrical grounding as required per NEC section 250. Any PCR user is reference for DEI. There have been no reported failures of a PCR for any reason.

Specific comparison of polarization cells to Dairyland PCR

DC leakage current DC leakage current through the polarization cell is typically 1mA to about 40mA, while blocking 0.5V to 1.5V, respectively. This represents the amount of cathodic protection current that will be allowed to leave the pipeline through the device. Beyond about 1.2V, the polarization cell conducts heavily.

The PCR leakage current for the same voltage range as above is about 0.005mA to 0.5mA. It represents a reduction in leakage current to approximately 1/100th of that of a polarization cell, keeping the cathodic protection system current requirements minimized.

Lightning Surge Current Rating PCR: 100,000A crest (8x20 microsecond waveform) Polarization cell: no published value

AC Fault Current Ratings PCR: Various, stated at 1, 3, 10, 30 cycles for each rating Polarization cell: Various, 30 cycle rating

Blocking voltage: PCR: 3V Polarization cell: 1.2V typ. The polarization cell is sometimes arranged with two or more in series to achieve a higher blocking level. Our solid state approach never requires this.

Failure mode: PCR: Fail-safe; the device will always fail as a dead short Polarization cell: fails open

Neither device is a one-shot device. The PCR can see an unlimited number of operations within its rating. Any failure is non-eventful, and the unit can be easily factory repaired and returned. There have been no failures in the history of the product. The "fail-safe" approach is a significant safety issue, protecting workers and equipment.

Hazardous electrolytes: PCR: none Polarization cell: Potassium hydroxide

Maintenance requirements: PCR: none Polarization cell: regular fluid checks. Occasional fluid replacement. Eventual disposal of electrolyte.

The cost of maintenance over the life of the polarization cell, coupled with the cost of safety matters, liability, environmental damage, and decommissioning, has driven a significant number of past users of polarization cells to replace them with PCRs. This is evident at most major power utilities, and a vast number of gas and liquid pipeline systems. Many major consulting engineers now specify our solid-state devices for DC isolation and AC grounding.

Third party listing: PCR: UL and C-UL listed as an "effective grounding path," and can be installed in grounding conductors of electrical equipment. Also listed for hazardous locations: Class I, Division 2 Polarization cell: none There are actually no other known devices that are third party listed in this area.

PCR 3.7KA or PCR 5KA
Quantity Weight Packaged Dimensions
1 11 18x7x8"
2 22 16x18x15"
4 45 16x18x15"
PCR-10K
Quantity Weight Packaged Dimensions
1 14 18x7x8"
2 30 16x18x8
4 60 16x18x15"
PCR-3.7KA/80A or PCR-5KA/80A
Quantity Weight Packaged Dimensions
1 15 18x8x8"
2 30 20x14x14"
4 60 18x16x17"
PCR-10KA/80A
Quantity Weight Packaged Dimensions
1 16 18x8x8"
2 35 16x18x15"
4 65 18x17x18"
PCR-15KA/80A
Quantity Weight Packaged Dimensions
1 21 20x12x10"

Note: For other PCR models or quantities, contact Dairyland for more information.