The Benefits of Transient Discriminating Technology

The secret to nVent ERICO’s Transient Discriminating Technology is its active frequency discrimination circuit.This patented device can discriminate between a temporary over-voltage (TOV) condition and a very fast transient, which is associated with lightning or switching-induced surges. When the transient frequencies are detected, the patented Quick-Switch within TD activates to allow the robust protection to limit the incoming transient. The frequency discriminating circuit that controls the Quick-Switch helps ensure that the SPD device is immune to the effects of a sustained 50 or 60 Hz TOV. This allows the device to keep operating, in order to help provide safe and reliable transient protection, even after an abnormal over-voltage condition has occurred.

Transient Discriminating Technology Surge Protection

Traditional Technologies

Conventional SPD technologies utilize metal oxide varistors and/or silicon avalanche diodes to clamp or limit transient events. However, these devices are susceptible to sustained 50/60Hz mains over-voltage conditions which often occur during faults to the utility system. Such occurrences present a significant safety hazard when the suppression device attempts to clamp the peak of each half cycle on the mains over-voltage. This condition can cause the device to rapidly accumulate heat and in turn fail with the possibility of inducing a fire hazard.

TD Technology – Features & Benefits:

  • Long-life by eliminating SPD failure under TOV conditions.
  • Fully compliant with UL 1449, Edition 2.
  • Extended Maximum Continuous Operating Voltage makes this technology ideal where the integrity of the utility power cannot be guaranteed.
  • No reliance on permanent over-voltage disconnects means continued protection even after abnormal over-voltage events.
  • High surge capacity with low suppressed voltage ratings.

The Core of  TD Technology

The secret to ERICO’s Transient Discriminating Technology is its active frequency discrimination circuit. This patented device can discriminate between a temporary over-voltage (TOV) condition and a very fast transient, which is associated with lightning or switching-induced surges. When the transient frequencies are detected, the patented QuickSwitchTM within TD activates to allow the robust protection to limit the incoming transient. The frequency discriminating circuit that controls the Quick-SwitchTM ensures that the SPD device is immune to the effects of a sustained 50 or 60Hz TOV. This allows the device to keep operating, providing safe and reliable transient protection, even after an abnormal over-voltage condition has occurred.

Meeting & Exceeding UL Standards

The CRITEC® range of surge protection devices from ERICO employing TD technology has been specifically designed to meet and exceed the new safety requirements of UL 1449 Edition 2. To meet the abnormal over-voltage testing of UL 1449 Edition 2, many manufacturers of SPD devices have incorporated fuse or thermal disconnect devices which permanently disconnect all protection from the circuit during an over-voltage event. Transient Discriminating technology on the other hand will allow the SPD device to experience an abnormal over-voltage up to twice its nominal operating voltage and still remain operational even after this event! This allows the device to provide safe, reliable and continuous protection to your sensitive electronic equipment. TD technology is especially recommended for any site where sustained over-voltages are known to occur, and where failure of traditional SPD technologies cannot be tolerated.

The UL 1449 testing standard addresses the safety of a TVSS device under temporary and abnormal overvoltage conditions but does not specifically mandate a design that will give a reliable, long length of service in the real world. Specifically, UL 1449 tests that the TVSS remains operational at 10% above nominal supply voltage, allowing SPD manufacturers to design products that permanently disconnect just above that. Most reputable manufacturer’s designs allow for up to a 25% overvoltage, while ERICO’s TD Technology gives even greater overhead.

Range of Products with nVent Erico’s Transient Discriminating

DIN Rail Surge Diverters

The DIN Rail mounted EDT2 family of SPDs provide reliable protection against voltage transients within the IEC Class II and UL Type 2 environments. In addition, nVent ERICO’s Transient Discriminating (TD) technology ensures continued operation during and after sustained and abnormal over-voltage events. Tested and independently certified to the IEC (via VDE) and UL standards, the EDT2 Series provides a range of safety and performance features for the harshest environments and suitable for protection within a wide range of applications. The EDT2 Series provides extended service life in the harshest of environments, ensuring your equipment and systems are kept safe and operational through extreme abnormal voltage conditions.

Panel Mount Surge Diverters

The TDS-MOVTEC family of surge diverters offers economical and reliable protection from voltage transients in even the most strenuous applications.The small footprint provides integrators and OEMs with an effective use of real estate when installing within panels and equipment.

DIN Rail Transient Surge Filter

The nVent ERICO Critec Transient Surge Filter (TSF) product family is a UL registered, IEC compliant, compact, serviceable solution for protection of PLC controllers, SCADA systems, motor control centers and other process control systems.

Panel Mount Surge Reduction Filter N-Series

Critec SRF N-Series combines rugged Spark Gap technology with effective true L-C filtering and Transient Discriminating (TD) Technology to help create the ultimate in effective and reliable AC surge protection.

  • High surge rating ideal for exposed critical service entrance applications
  • Reduces let-through voltages and rate-of-voltage rise (dv/dt) and helps provide optimum protection for electronic equipment
  • Extreme reliability and simplified design with direct connection from input to output
  • Comprehensive front panel status and internal diagnostic LEDs