The 587B series of AC power line overvoltage protectors are intended for use in permanently connected applications such as remote equipment instrumentation cabinets, Original Equipment Manufacturers(OEM) products and industrial control systems. In such applications the equipment electronics needs protection from repeated, AC line conducted, transient overvoltages. Our clamp ratings for a 3000 Amp transient are 400 Volts and 800 Volts respectively for 120 Vrms and 240 Vrms protectors. These ratings assure a comfortable protection margin because they are well below the off line switch mode power supply(SMPS) transistor breakdown voltages. Note that to qualify for these ratings the actual clamp performance on test units must average less than the ratings, after repeated transients. Such performance is achieved by using a conservative approach, i.e., creating transient handling capability that greatly exceeds the application threat definition of 3000A 8x20usec for a permanently wired device. By designing the circuit to spread the transient current over a number of suppression components, the stress on each component is less. This results in the ability of the protector to handle 100+ of the atypical rated maximum 3000 Amp pulses. At typical, much lower pulse current amplitudes, this durability results in substantially longer life. This conservative design philosophy is also reflected in the protectors ability to operate at full load current without heatsinking. Low resistance internal current paths minimize the heat generated at a given current.

How To Choose a Protector

There are two important electrical ratings, the nominal operating voltage and the maximum load current. Select a protector with a rated voltage greater than the operating voltage. Then select a protector with a current rating greater than the maximum load current. For example, a 120V, 3A use, select a 587B051 rated at 120Vac and 5 Amperes. For a 240V, 7A use, select a 587B102 rated 240Vac and 10 Amperes.