Surge Protection

Surge protections systems (also known as Surge Protection Devices) reduce or eliminate harmful transients, surges and electrical line noise and thereby prevent damage to sensitive electrical equipment. Transients are short duration power anomalies caused by the sudden release of electrical energy. Every year millions of dollars of hardware will be saved from damage by installing surge suppression systems. National Power Corporation utilizes products from Thor Systems, which is a world-class manufacturer of surge protection devices. Thor Systems products meet UL standards.

Thor Systems, Inc.

Thor Systems was founded on the dedication of exceeding the expectations of their customers. Their five senior staff members have 117 years’ cumulative experience in the power quality/surge protection industry and are pleased to support technical questions and specific applications, including site visits for power quality problem evaluation. Thor Systems’ commitment is evident in all facets of our business from delivering product value, high performance/full surge rated designs to providing the correct power quality solution for specific applications.

Design Philosophy

Applying a small number of large block TpMOVs (34 mm square/50kA with “Fail Safe Design”):

100 times pulse life vs. 18 to 20mm dia. MOVs used in arrays by a number of competitors
Prevents cascading failures which can result in increased voltage let-through levels.

Hybrid design utilizing SADs, TpMOVs, and FILTER CAPACITORS for optimum surge protection:

Silicon Avalanche Diodes (SADs): Non-linear diverting element/speed of turn-on/low clamping levels
Thermally Protected Metal Oxide Varistors (TpMOVs): High energy handling capacity
Filter Caps: EMI/RFI noise suppression reducing data errors, lockups, and reboots.

Modular Designs Offered – Series TSr Products

Field replaceable, upgradable modules
50 through 300kA per mode (all modes protected)
Applications: Service Entrance, Main Distribution, and where protected equipment criticality is a vital consideration.

Non-modular Designs Offered – Series TSn Products

Compact, non-field replaceable modules
50 through 150kA per mode (all modes protected)
Applications: Lower ampacity Distribution, Subdistribution, and Branch Panels.

Providing Solutions

Coordinated surge protection provides ability to dissipate transient/surge energy from external (20%) and internal (80%) sources.
Surge protection matched to the facility’s electrical environment using a 3G Site Shield Risk Assessment Spreadsheet (utilizing seven factors of susceptibility for each specific application to assure proper sizing vs. risk).

Thor Systems offers products and services that provide protection from the more obvious external to the more frequent internal transient voltage sources. Their consistent focus on improved product performance and increased value to the customer is conveyed by their products’ transparent cover enclosures, showcasing the TILE Architecture, Innovative Design Configurations, and per Mode Status Indication.

Bottom Feed Surge Protection Device

Engineers’ comments during Thor Systems’ Power Quality/Product Presentation expressed a preference for an SPD with a “Bottom Feed” configuration. Continuing discussions defined further unique solutions to satisfy specific applications as listed below. Since the 2008 introduction of the Bottom Feed module, the demand for this
configuration has increased. Today 90% of Modular SPDs are Bottom Feed configurations.

Application

Service Entry/Switchgear/Main Distribution/ATS and Pump Stations.

Product

Modular Design configured for Bottom Feed with Terminal Block (normally fed by 3 Pole 60 Amp circuit breaker supplied by customer) or fused disconnect switch (factory installed, providing total isolation for serviceability and supports direct busbar termination).

Ease of installation: Direct coupling the SPD to the top of Switchgear/Distribution Panels or Automatic Transfer Switches totally simplifies installation without restricting service access to distribution gear.
Reduces lead length: Eliminates unnecessary conduit runs and loops.
Improved status visibility: Each individual module features solid state indication lights (Green/module active and Red/module replacement needed). The SPD is housed in a NEMA 4X fiberglass enclosure with a hinged clear Lexan cover, making the status of every surge protection module (typically 7, Wye configuration) always visible.
Improved serviceability: A separately mounted SPD, which may be isolated by a circuit breaker or fused disconnect switch offers service access without requiring additional arc flash protection measures.