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Electronic Track Signal Protector


The nVent ERICO Electronic Track Signal Protector series provides transient protection from surges induced or conducted onto low-voltage signal circuits for trackside signaling equipment. The series of surge-protection devices is ideal for protecting DC-responsive track relays, train-detection systems, microprocessor-based train-control and indication circuits, train inspection systems, communications systems, highway crossing controls and other operationally sensitive systems. nVent ERICO Electronic Track Signal Protector devices help ensure that surges do not pose a safety threat in the event of component failure. Indicators on the device help safeguard the device against shorts and provide status indication at a glance. The device cover is marked with the operating voltage and part number, which allows easy identification as to proper application.


  • Includes hybrid technology comprised of gap-type voltage switching and varistor-type voltage clamping components
  • Designed with a fail-safe, isolated from ground failure modes as required for critical signal circuits
  • Protects sensitive electronic equipment in exposed locations
  • Epoxy coating helps ensure stability of operation under adverse conditions and in locations of high humidity
  • Exceeds the AREMA® specifications for both arrestor and equalizer applications
  • Provides a 50 kA 8/20 maximum surge rating for protection that is suitable for exposed trackside equipment


Part Number ETSP33050
Nominal System Voltage (Un) 50 VDC
35 VAC
Max Continuous Operating Voltage (Uc) 90 VDC
65 VAC
Voltage Protection Level (Up) 300 V @ 3 kA
Nominal Discharge Current (In) 30 kA 8/20 μs L+L-PE
Max Discharge Current (Imax) 50 kA 8/20 μs L+L-PE
Leakage Current @ Un 1 nA Max
Frequency 5 MHz Max
Protection Modes Two Mode, L1-PE and L2-PE
Technology Metal Oxide Varistor (MOV)
Gas Discharge Tube (GDT)
Connection Type AREMA® Stud-Type Terminals – 2 Post Terminal Block
Status Indication Dual spring thermal disconnect
Enclosure Material UL® 94V-0 Thermoplastic
Enclosure Rating IP 20
Humidity 0 – 90 % RH
Temperature -40 to 176 °F
Depth (D) 0.98"
Height (H) 2.96"
Width (W) 2.16"
Unit Weight 0.24 lb
Complies With ANSI®/IEEE® C62.41.2-2002 Cat A, Cat B, Cat C
IEC® 61643-1 Class II
AREMA® requirements
Color Transparent
Standard Packaging Quantity 1 pc
UPC 78285658581
EAN-13 8711893145830
Frequency @ 3 dB / 120 Ω.

nVent, nVent CADDY, nVent ERICO, nVent ERIFLEX, and nVent LENTON are owned by nVent or its global affiliates. All other trademarks are the property of their respective owners. nVent reserves the right to change specifications without prior notice.

ANSI is a registered trademark of American National Standards Institute.
AREMA is a registered trademark of American Railway Engineering and Maintenance-of-Way Association, Inc.
IEC is a registered trademark of the International Electrotechnical Commission.
IEEE is a registered trademark of The Institute of Electrical and Electronics Engineers, Inc.
NEMA is a registered service mark of National Electrical Manufacturers Association.
UL, UR, cUL, cUR, cULus and cURus are registered certification marks of UL LLC.





Instruction Sheets

ETSP Series
1.29 MB English