Control Panel Layout and Mounting of Electronic Components
In building the subpanel, it is best to secure the components from the front side. This will make it easier to replace any failed device or component in the future. We can also make installation and maintenance easier by using terminal blocks mounted to the subpanel that will connect to all external devices. This will allow the installing electrician to quickly dress and terminate the field wires. Another terminating method that has added benefits is to design our control panel using mating connectors also known as connector plugs. This terminating method enables field wiring to be simply plugged into connectors mounted on the panel.
Electronic instrumentation is typically installed inside an enclosure with other devices. Therefore, the installation of the instrumentation must take into consideration that the panel layout accommodates all necessary components. In addition to the panel layout, the following should be considered.
Electronic instrumentation can be affected by interference from other electronic devices or EMI (Electromagnetic Interference). This interference causes static that may interrupt communications or signals from other devices. Use these guidelines to prevent any possibility of interference with your equipment:
- Environmental specifications that cover the operating temperature, humidity, vibration, noise immunity, etc.
- Power requirements are specific to each piece of equipment. When installing instrumentation always make sure to follow the manufacturer's power requirement guidelines for your specific piece of equipment.
- Use components with Agency Approvals such as UL (Underwriter Laboratories), CE (Conformitè Europëenne), etc.
- Make enclosure selections based on component dimensions, recommended mounting clearances, heat dissipation, and EMI.
If installing a PLC (Programmable Logic Controller) base or chassis which consists mainly of mounting, bonding, and grounding, it is very critical to the proper operation of the PLC and its related devices and components to closely follow the manufacturer's recommendations. There are many causes of a PLC experiencing "noise" problems when the problem is found to be that the base wasn't grounded to the subpanel.
Next week we will go into detail about wiring recommendations, grounding requirements, and the importance of shielded cables for a well-designed control panel.