SuppresSurge Railmount Protectors are distinguished by their compact, easily mounted housings. The housing holds multi-element high energy, primary protector circuits with screw terminal inputs and outputs and a stud ground connection. A unit provides 2 lines/1 loop, 4 lines/2 loops or 8 lines/4 loops of overvoltage protection for communication lines and control loops with power supply voltages from 12 to 60 Vdc. The protectors snap on and pry off DIN rail types: mini (NS15 per DIN EN50), C(NS32 per DIN EN50035) and flat bidirectional (NS35/7.5 or NS35/15 per DIN EN50022).
Two stage units use the classical three element, high energy, primary protection circuit with a rugged GDT input and rapid response TVS diode output separated by a ten Ohm isolating resistor. They provide excellent protection for most applications. Three stage units enhance performance for sensitve equipment by adding and isolating impedance and an MOV as an intermediate stage. High current versions substitute 2 Amp inductors for the half Watt 10 Ohms carbon compostition resistors. Three stages are particularly recommended on high current units when inductors are used for isolating the stages. This is because unlike the fixed value of a resistor, the value of the isolating impedance using inductors is dependent upon the transient rise time. The additional stage enhances performance on slower rising overvoltages.

How To Choose a Protector

Select a protector with a voltage rating equal to or greater than the maximum operating voltage in the application. Typically, this is the maximum voltage of the regulated power supply used to energize the circuits being protected. The xx after the R in the product name is the protector voltage rating.
The first number after CLPS, 2, 4, or 8, indicated the number of lines of protection per unit. The second number after CLPS, 2 or 3, indicates the number of stages of protection per line. The third number after CLPS, 1, 2 or 3, indicates the number of modes of protection. One mode is L-L only. Two modes is for two L-Gs which also provides L-L at two times the L-G protection. Three modes is for two L-Gs and dedicated L-L which protects at less than two times L-G protection.
For control lines requiring significantly more current capability than 100 mA, select a high current CLPSXXXRXX00 type protector. The line current rating of 100 mA is a very conservative derate for the 1/2 Watt series resistor. Without derate it can handle 222 mA up to 70 degrees Celsius. If the duty cycle is less than 100% line currents above 222 mA are permissible. The screw terminals are rated for 10 Amp.