How do you maintain and clean your PLC hardware components and equipment?

Step 1: Turn Off the Power Before starting any maintenance or cleaning procedure, ensure that the power to the PLC system is completely turned off. This prevents any risk of electrical shock or damage to the equipment during handling.

During inspection a key step would be to clean or hit all open contact surfaces with a fiberglass pencil to ensure clean surfaces for proper contact.

Step 2: Inspect the Components Visually inspect all the PLC components, including the CPU, input/output modules, communication modules, power supply, and any connected cables. Look for signs of physical damage, corrosion, loose connections, or accumulated dust.

Check the materials you use doesn't contain static materials like nylon etc - Fellowes has a can of compressed air that is de ionized to prevent static discharge -I disagree with the vacumn because it ionizes the air which can cause charged particles to discharge through the electronics -a static discharge wrist strap is available with a crocodile clip which just clips onto the local earth to reroute the discharge path of accidental electrostatic discharge (a little old school but still effective)

Let's be honest... No one cleans a PLC... The times I've seen them getting cleaned was before a panel is turned on. The goal was to remove any debris / particles from construction, cabling, metal shavings from drilling the panel. Don't let those fall into the PLC as they can easily short a circuit or cause a premature hardware failure.

A good tip when cleaning the PLC component to avoid unwanted contact to sensitive parts is using an isolator hand gloves. An example of this is nitrile gloves or surgical gloves. They are convenient and protect sensitive part from harm due to its insulation and static dissipative properties

The vacuum cleaner should preferably be anti-static to avoid any surprises. You also have to be very careful to avoid the wiring.. Touching a loose wire could have disastrous effects. This is why part of the maintenance plan should be to torque or at least tighten wiring connections

For the maintenance part, it is necessary to have a significant inventory of PLC and its component in case of hardware failure or any unforeseen circumstances. Cleaning PLC's on a running plant does not happen. No one would want to have a headache of removing wires for I/O terminals and managing them in certain order just to clean a PLC.

Unclog the condensate lines. You don't want a high-level switch shutting off the cooler. You really don't want the fan blowing water on your PLC and VFDs. If some moron designed the panel with no cooling, at least install one fan and one filter diagonally across the panel. Draw in cool, exhaust hot.

Step 4: Check the Cooling System Inspect the cooling system, including fans and vents, to ensure they are clean and free from obstructions. Proper cooling is essential for preventing overheating, which can lead to premature component failure. Clean any dust or dirt buildup around cooling vents.

Oh, this can get so frustrating. Sometimes, you need a floating instrument ground. Usually, earth is fine. Except for the instrument ground, which all your 24V com should be bonded to, don't let your AC and others float around randomly. Use a faraday shield to filter out imbalanced spikes from the step down feed. Good isolation is important, especially if the closest upstream transformer is feeding a bunch of other stuff. Put some snubbers in there if you're switching some big loads, too. They'll take the spikes out. This isn't rocket science. Just provide clean power and mitigate any swings in your panel.

Step 5: Check the Grounding System Verify that the grounding connections are secure and free from corrosion. Proper grounding is critical for electrical safety and to prevent issues like electrical noise or interference in the PLC system.

After cleaning and inspection, power up the PLC system and perform functional tests to ensure that all components are working correctly. Test input/output operations, communication with peripherals, and any specific functionalities of the PLC program. Additional Considerations: Regular Maintenance Schedule: Establish a regular maintenance schedule based on environmental conditions and usage intensity. Backup Programs: Before any maintenance, ensure that you have a backup of the PLC program to restore in case of unexpected issues. Environment Control: Keep the PLC system in a clean and dust-free environment to minimize the accumulation of debris.

If it’s not important to you that they still function after cleaning you can never go wrong with a dip in industrial solvent, power wash, and then bake in a heat treating oven to dry. If it is important…probably ask someone else.