ESI Products

ESI Thermal Overload Monitor

The ESI Thermal Overload (TOL) Monitor 8901 is engineered to offer a cost effective solution for monitoring and indicating status of TOL protection circuitry, requiring no additional cable or visual/audio alarm in the control room. In the control circuits, the ESI Monitor 8901 provides indication of TOL relay (49) contact status both locally and remotely in the control room, using existing cables and indicating lights. It requires simple installation and four wiring connections within the Motor Control Center (MCC) Cubicle.

The ESI Monitor 8901 is easily interconnected into a Motor Operated Valve (MOV) circuit as shown below. In the circuit, it continually monitors the TOL relay (49) contact status. Upon detection of an open contact, the energized valve position indicating lights flash at an acceptable human engineered visual alarm rate of approximately four (4) Hertz. Providing positive indication of contact status and valve position. The integral design of the monitor includes a test switch for on-line testing, local indication and protective fusing. Monitors are manufactured in accordance with MIL-9858A and are available for both AC and DC control circuits.