Reliable Protection Performance for AC Infrastructure Designs

New Bourns® SPD Gets a Hybrid Makeover

Lately, Bourns has been using its extensive component engineering expertise to maximize circuit protection performance. By creating hybrid designs, we’ve been able to expand features and overcome limitations.  A case in point is the Bourns® Model 1202 SPD.  This new SPD combines a Metal Oxide Varistor (MOV) with a Gas Discharge Tube (GDT). From Bourns’ innovation, AC infrastructure designers can utilize an improved SPD that provides consistent, long-life, reliable and enhanced protection performance.

We designed the Model 1202 series to address the shortcomings of MOVs alone. An MOV that has had long-term overvoltage exposure can start to fail due to excessive leakage, which can lead to power dissipation, with the potential to eventually cause an overtemperature condition. Surge history, time, and temperature all contribute to increased leakage current in an MOV. This situation can also produce application damage due to watt loss heating. Applications that are subject to voltage transients typically need more protection than an MOV can provide by itself.

The features offered in the Model 1202 SPD deliver superior lightning threat protection, up to rated limits, and for AC power-induced problems. Applications such as service entrances, branch and OEM panels, electrical infrastructures, exposed equipment and systems cabinets require an extended level of protection.

So, what makes this new SPD so great?  The key to its performance is the powerful combination of fast-responding MOV technology in conjunction with low leakage GDT technology.  By using the GDT to isolate the MOV from the line voltage, this advanced design shields the MOV from transients and temporary overvoltage spikes that can potentially damage it over time. The ultra-low leakage of the GDT also helps to reduce damage due to watt loss heating. As a Type-1 SPD, the Model 1202 requires no external line fusing or circuit breaker, can be placed on the line side of the main service disconnect and can be used indoors or outdoors. And, combining a GDT with an MOV does not impact signal or system operation.

Bourns® Model 1202 Series is available in a 120 Vrms version as well as a 120/240 Split Phase version. The Model 1202-240S is capable of covering six (6) modes of protection on a 120/240 split installation, and is designed to offer comprehensive protection of symmetric modes. Plus, the new SPD series employs a full multi-mode protection scheme that can be utilized in line-to-line, line-to-neutral and neutral-to-ground configurations. Bourns is a leader in offering the number of modes protected, and today there are few suppliers that have a complete hybrid Type 1 SPD in a small footprint.

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