Siemens has introduced a new line of self-powered ESP200^TM Overload Relays for industrial and construction applications, designed to reliably operate in the most demanding environments. The line replaces the ESP100 Overload Relay and is offered with both automatic and remote reset features.

Think of it as a form of “life insurance” for your motors. In cases where electric motors have frequent overload tripping, or shortened effective operating life, these Siemens devices can help.

Using an overload relay can not only extend motor life, it can also reduce inventory costs and lower your yearly maintenance budget.

While protecting the motors, the self-powered ESP200 has been designed to operate at a wide range of temperatures and be insensitive to ambient temperatures that do not affect motor operation. It will work reliably under the harshest conditions. These features prevent nuisance tripping and increase motor uptime. The ESP200 even protects itself in the event of a short circuit, unlike bimetal or melting alloy overload relays. This eliminates the need to replace the overload after a short circuit.

It is also highly flexible, offering field selectable adjustments; trip class, FLA, ground fault protection, phase loss and phase unbalance.

Easily configured without software or manuals, the new ESP200 line delivers unmatched repeat accuracy of 99 percent. Versatile by design, the ESP200 takes the guess work out of meeting numerous overload protection requirements. Field selectable Trip Class 5, 10, 20 or 30 can easily be set by two DIP-switches and the FLA dial allows for a wide adjustment range (4:1). This simple and versatile configuration enables companies to reduce overload relay inventories by up to 40 percent.

The easy-to-use relays have removable terminals, allowing the ESP200 to be changed without removing control wiring. DIN rail mounting for easy installation and visible trip indicator for faster identification of overload trips are just a few of the ways that these features make installation and regular operation easier for all involved. One NO and one NC contact is standard which makes it simple for the user to wire local contacts.

The ESP200 has touch-safe terminals to prevent accidental touching of live circuits. The ESP200 is UL listed and CSA certified according to the strictest standards. With ground fault detection that trips at 60 percent of motor current, the ESP200 protects against high resistance short circuits or ground faults due to moisture, condensation, insulation damage or other reasons. To protect motors against overheating and related temperature damage, the ESP200 also has phase loss protection that trips in less than 3 seconds, phase unbalance protection and thermal memory to prevent the motor from restarting while too hot.

For critical applications such as refrigeration, select auto reset mode. In auto mode, the ESP200 overload relay will automatically reset in three minutes after tripping, allowing the motor to cool down before restart. There is also a test button that triggers a complete electronic functions test, including the trip mechanisms. These easy-to-use features all contribute to increased motor uptime and a better return on your investment.

For more information about Siemens ESP200 overload relays, look at the online simulator or write to IBT.