SSD

SSD

Solid-State Decoupler

The Solid-State Decoupler (SSD) uses proven, solid-state construction combined with innovative production and packaging techniques, to offer exceptional performance while lowering the cost of applying protection products to industry. With ratings for AC fault current and lightning, and the ability to pass steady-state AC current, the device outperforms other technologies such as metal oxide varistors, gapped arrestors, and polarization cells. Now proven over many years, the SSD is the most commonly used Dairyland decoupler in the world.

Features and Characteristics

  • Compact, lightweight package
  • Range of AC Fault Ratings
  • 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
  • Submersible Design
  • EAC Certified Products Available - Learn More Here
    Certifications
 
      
  • threshold voltage
  • -2/+2V (standard)
  • -3/+1V (optional)
  • For other product options, contact Dairyland
  • ac steady-state current (amperes - rms) 50/60Hz
  • 45A (standard)
  • lightning surge current
  • 100kA crest (4 x 10 µs waveform) for 5.0KA, 3.7KA and 2.0KA models
  • 75kA crest (4 x 10 µs waveform) for 1.2kA models
  • environmental rating
  • IP68 - submersible (to 2m depth)
  • 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 SSD
AC Fault Current (amperes-rms) 50/60 Hz
Model 1 cycle 3 cycles 10 cycles 30 cycles
1.2KA 2,100 1,600 1,400 1,200
2.0KA 5,300 4,500 3,700 2,000
3.7KA 6,500 5,000 4,200 3,700
5.0KA 8,800 6,800 5,700 5,000
View Model Number Description Chart

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

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

The SSD 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
SSD Model Numbers

Literature:
SSD - One Page Data Sheet
SSD - Technical Literature
SSD - Installation Instructions

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

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

 

The SSD has been tested by various Nationally Recognized Testing Laboratories (NRTLs) for various aspects of its operation, ratings, and construction. These include:

Safety Grounding

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

  • Providing an "effective ground-fault current path" as defined in 2005 NFPA 70 (US National Electrical Code - NEC), Article 250.2, and required in 250.4(A)(5)
  • Similarly, it meets the same per Canadian Standards Association CSA C22.2 No. 0.4-M1982 (reaffirmed 1999), using Canadian Electrical Code Part I, section 10-500, 10-806 as a guide.
  • Providing over-voltage protection in accordance with the applicable requirements of ANSI C62.11

Listing assures compliance to the above standards by DEI devices in providing electrical over-voltage protection and safety grounding.

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 SSD has been listed for use in Class I, Division 2, Groups A, B, C, D hazardous locations by UL and C-UL, according to:

  • U.S. National Electrical Code section 500-505
  • UL 1604: "Electrical Equipment for Use in Class I and Class II, Division 2, and Class III Hazardous (Classified) Locations"
  • CSA C22.2 No.213-M1987: "Non-Incendive Electrical Equipment for Use in Class I, Division 2 Hazardous Locations"

Liquid Filled

Comparison of Dairyland SSD 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 SSD:
The SSD is a solid-state device which provides DC isolation and AC grounding, up to a threshold of 2 to 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 is based on established DEI technology that is fail-safe and maintenance-free. 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, Dairyland offers the only UL listed devices for providing an effective grounding path for electrical grounding as required per NEC section 250.

Specific comparison of polarization cells to Dairyland SSD
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 SSD 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:
SSD: 75,000A or 100,000A crest (4x10 microsecond waveform)
Polarization cell: no published value

AC fault current ratings:
SSD: Various, stated at 1, 3, 10, 30 cycles for each rating
Polarization cell: Various, 30 cycle rating

Blocking voltage:
SSD: 2 or 3V, depending on model
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:
SSD: Fail-safe; the device will always fail as a dead short
Polarization cell: fails open

Neither device is a one-shot device. The SSD can see an unlimited number of operations within its rating. The "fail-safe" approach is a significant safety issue, protecting workers and equipment.

Hazardous electrolytes:
SSD: none
Polarization cell: Potassium hydroxide

Maintenance requirements:
SSD: 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 our solid-state technology. Â Many major consulting engineers now specify our solid-state devices for DC isolation and AC grounding.

Third party listing:
SSD: 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. Certified by UL/Demko for use in Zone 2 locations.
Polarization cell: none

There are actually no other known devices that are third party listed in this area.

All SSD Models with 1.2KA Fault Current

Quantity Weight Packaged Dimensions
1 5 5x4x13"
2 10 14x10x5"
4 19 14x10x10"
8 40 16x18x15"
12 56 20x17x15"
All Other SSD Ratings
Quantity Weight Packaged Dimensions
1 5 5x4x13"
2 10 14x10x5"
4 20 14x10x10"
8 38 16x18x15"
12 58 20x17x15"

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