Increased Need for Reliability, Safety Drive Use of Hybrid RF Surge Protectors and Filtering Technology
The U.S. Rail Safety Improvement Act of 2008 mandated the adoption of a positive train control (PTC) system to eliminate human error in trains responding to communication signals sent by wayside systems. PTC technology can accelerate, decelerate and stop trains and thus prevent collisions and over-speed derailments.
PTC Systems Need Surge Protection
A key to PTC’s success is for both operations control centers and wayside equipment (WIUs) to be properly grounded and protected from power surges caused by lightning and other anomalies. The sensitive digital equipment used in PTC systems demands advanced surge protection technologies. This blog post discusses one of these advancements and then summarizes the key features of PolyPhaser’s vast array of railroad RF surge protectors.
Hybrid Surge Protectors: 2 Stages Are Better Than 1
The PolyPhaser’s GX series of RF lightning arresters has been adopted by rail operators for over 10 years. They are based on a hybrid circuit that takes advantages of the response time of a diode, but also incorporates the current handling capabilities of a MOV and a gas tube. The PolyPhaser GX hybrid circuit incorporates coordinating inductors between protection devices, which improves the response time. The result is a fast-acting RF surge arrester that has one of the lowest energy and voltage let-through amounts on the market. The illustration below shows the protection circuit used in PolyPhaser’s GX RF lightning arrester.
Test results show that under multiple and single max surge pulses, the PolyPhaser surge arresters show no degradation.
Railroads that install GPS equipment along the tracks will be happy to know PolyPhaser now offers the DGXR+06NMNF-Z to provide the best protection for radios operating from 550 to 2700 MHz.
Single-Point Grounding Helps Protect Electronics
Whenever RF protectors are used in an enclosure that contains equipment that is grounded on the incoming AC side, grounding each piece of equipment to the earth at different points can cause component damage and even personal injury. Multiple ground points can cause ground loop currents, which pose a safety threat. Thus, we recommend using single-point grounding in railroad structures. Contact PolyPhaser to learn more about single-point grounding.
PolyPhaser’s Railroad Surge Protectors
PolyPhaser offers reliable RF coaxial surge protection that exceeds standards set by the American Railway Engineering and Maintenance-of-Way Association (AREMA). Our surge protection devices are each tailored for one of three main applications:
- Voice and PTC radio – 100 to 512 MHz
- Cellular – 698 MHz to 2.7 GHz
- Radio and GPS apps that require power on the coax line– 550 to 2700 MHz.
To find the exact model that will meet your needs, see our Railroad RF Applications data sheet. You can also view our entire line of railroad RF surge protectors, where you’ll find more than 50 SPDs that cover a wide gamut of specifications, including:
- Frequencies ranging from DC up to 10 GHz
- Connectors such as N, UHF, 7/16 DIN, TNC and F
- Power handling range from 40 watts to 3 kilowatts
- Low-PIM options
- DC block and DC pass
- Waterproof IP67 and hazardous location options
See our entire line of railroad RF surge protection products as well as our PTC filter series for railroad RF band pass, and contact us if you have any questions. We have a huge inventory of in-stock products and offer same-day shipping to keep your railroad systems on track.
