In that event, check for and correct overvoltage or undervoltage conditions, which can cause coil failure. Be sure to dean any residues of melted coil insulation from other parts of the device or replace such parts. In the manual for the product. Pilot Lights - Replace any burned out lamps or damaged lenses. Photoelectric Switches-The lenses of photoelectric switches require periodic cleaning with a soft dry cloth.
Reflective devices used in conjunction with photoelectric switches also require periodic cleaning.
Do not use solvents or cleaning agents on the lenses or reflectors. Replace any damaged lenses and reflectors. Use of other than factory recommended test equipment for solid state controls may result in damage to the control or test equipment or unintended actuation of the controlled equipment. Solid state devices require little more than a periodic visual inspection. Discolored, charred or burned components may indicate the need to replace the component or circuit board.