Building Automation
Industrial Automation
Power Automation & Safety
Bangladesh Distributor
Basic Switches
 Introduction
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Features |
| Principles | Classifications |
| Engineering Data |
Further Information
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Explanation of Terms
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Troubleshooting |
| Location of failure | Failure | Possible cause | Corrective action | |
| Failures related to electrical characteristics | Contact | Contact failure | ・ Dust and dirt on the contacts. | ・ Remove the cause of the problem, place the switch in a box, or use a sealed switch. |
| ・ Water or other liquid has penetrated into a switch. | ||||
| ・ Chemical substances have been generated on the contact surface due to the atmosphere containing chemical corrosive gas. | ・ Use a switch having contacts with high environmental resistivity (such as gold or alloy contacts). | |||
| ・ Chemical substances have been generated on the contact surface when the switch switches a very low load. | ||||
| ・ Solder flux has penetrated into the switch. | ・ Review the soldering method. | |||
| ・ Silicon gas exists near the switch. | ・ Remove the material generating gas, or adjust contact capacity to prevent formation of silicon compounds on the contacts. | |||
| Malfunction | ・ The contacts are separated from each other by vibration or shock. | ・ Use a switch having a high contact force (generally a high OF). | ||
| Contact welding | ・ The load connected to the switch is too high. | ・ Switch the load with a high-capacity relay or magnetic relay or insert a contact protection circuit. | ||
| Insulation degradation (burning) | ・ Contacts have been melted and scattered by arc. | ・ Switch the load with a high-capacity relay or magnetic relay. | ||
| ・ Water has penetrated into the switch because the switch has been used in an extremely hot environment. | ・ Remove the cause of the problem, place the switch in a box, or use a sealed switch. | |||
| ・ Liquid has penetrated into the switch and been carbonized by arc heat. | ||||
| Failures related to mechanical characteristics | Actuator | Operating failure | ・ The sliding part of the actuator has been damaged because an excessive force was applied on the actuator. | ・ Make sure that no excessive force is applied to the actuator, or use an auxiliary actuator mechanically strong. |
| ・ Foreign material like dust, dirt and oil has penetrated into the switch. | ・ Remove the cause of the problem or place the switch in a box. | |||
| ・ The actuator does not release because the operating body is too heavy. | ・ Use a switch having a higher OF. | |||
| ・ The switch is loosely installed and thus does not operate even when the actuator is at the rated OP. | ・ Secure the switch. | |||
| Low durability | ・ The shape of the dog or cam is improper. | ・ Change the design of the dog or cam. | ||
| ・ The operating method is improper. ・ The operating speed is too high. | ・ Review the operating stroke and operating speed. | |||
| Damage | ・ Striking or other excessive shock has been applied to the actuator. | ・ Remove the cause of problem or use a switch mechanically strong. | ||
| ・ The caulked part is not good enough or the assembled condition is poor. | ・ Replace the switch with a new one. | |||
| ・ Deformation or drop-out ・ Actuator was subjected to an excessive force and force from an inappropriate direction. | ・ Review the handling and operating method. | |||
| Mounting section | Damage | ・ Screws have not been inserted straight. | ・ Check and correct screw insertion method. | |
| ・ The mounting screws were tightened with too much torque. | ・ Tighten the screws with an appropriate torque. | |||
| ・ The mounting pitch is wrong. | ・ Correct the pitch. | |||
| ・ The switch is not installed on a flat surface. | ・ Install the switch on a flat surface. | |||
| Terminal | Damage | ・ An excessive force was applied to the terminal while being wired. | ・ Do not apply an excessive force. | |
| ・ The plastic part has been deformed by soldering heat. | ・ Reduce the soldering time or soldering temperature. (Refer to the information given under Safety Precautions for that model.) |
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