With the Dairyland SSD (Solid State Decoupler) line of products, Dairyland offers decouplers with lower cost and very compact designs. Using proven, solid-state construction, but with new production and packaging techniques, the innovation of the SSD line adds value by 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. A major application of the SSD is in acting as a "Ground Mat Decoupler" by separating grounding mats from pipelines (to improve cathodic protection), while still providing over-voltage protection for workers.
Features & 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
- Submersible Design
Accessories for SSD Solid State Ground Mat Decoupler
- MTF Flange Mount Bracket: Can be used to mount SSD across an insulated flanges of various size using existing flange bolts.
- MTS Mounting Bracket: Provides option of installing SSD on flange by pin brazing studs directly to the flange.
- MTT Mounting Bracket with Tapped Holes: Can be installed directly to flange using MTT kit and drilled/tapped holes directly on flange.
- MTL Lead Kit: Two #6 AWG conductors with compression connectors on each end to connect SSD. Available in 12" and 36" lengths.
- Hex Coupling Nut: Connects SSD to a steel pipe using pin brazed studs and Hex Coupling Nut to achieve shortest possible connection from SSD to pipe. MTL lead kits are often also purchased.
- Pedestal: Use this 36" padlockable fiberglass pedestal with any model SSD to enclose the device and all cable connections. Used in applications where cable lead connections come from below ground level, typically AC mitigation schemes.
Gradient control mats are installed around above ground pipeline structures to protect workers from potentially hazardous voltages that can be present on cathodically protected pipelines. Pipeline voltages can result from the following conditions:
- Induced AC voltage
- An AC fault in improperly grounded electrical equipment
- A lightning strike directly to or adjacent to the pipeline
The effectiveness of a gradient control mat is determined by the step potential and the touch potential that it allows for the voltage sources described. Unfortunately, no known manufacturer has provided any technical data on the effectiveness of their mat in limiting step and touch potentials. Additionally, single conductor mats such as the spiral configuration type, have been found completely ineffective in limiting step and touch potentials from lightning to safe levels.
Solution: Dairyland now offers an engineered Gradient Control Mat (GCM) to address lightning and AC fault current conditions, backed by analysis from experts in lightning protection and with a full review by Correng Consulting of the cathodic protection guidelines of this mat design. Step and touch potentials are now limited with the Dairyland grid-type mat, in a much lower cost design. Dairyland also recommends decoupling gradient control mats to improve CP on the pipeline, and offers the new, affordable Solid-State Decoupler (SSD) line for use in conjunction with the Gradient Control Mat.
A decoupling device such as the SSD is recommended for use in conjunction with the gradient control mat as it allows for several distinct advantages including:
- The galvanic potential of the mat material becomes irrelevant
- Pipeline CP readings can be taken in the vicinity of the mat
- Any interaction with the pipeline CP system is eliminated
- The life of the anodes used to protect the mat is significantly increased