When electrical components are not used for a long time, the core protection goal is to isolate environmental erosion (moisture, dust, corrosive gases), avoid electrical performance degradation, prevent mechanical structure damage, and ultimately ensure reliability and safety when they are put back into use. The protective measures should be designed according to the type of component (sensitive electronic components/high-voltage components), storage environment, and storage period (short-term<6 months/long-term ≥ 6 months). The specific plan is as follows:
1、 Core principle of protection: First, "clean and dry", then "seal and isolate", and finally "regular maintenance"
The prerequisite for the protection of all electrical components is the absence of stains, moisture, and residue, and subsequent sealing and storage can only take effect. The specific steps need to be followed:
Cleaning pre-treatment: Use a dry soft cloth to wipe the dust on the surface of the components. For precision electronic components (such as chips and sensors), compressed air (pressure ≤ 0.3MPa, vertical distance ≥ 10cm) can be used to blow away the gap dust. Avoid using solvents such as alcohol (which may corrode the pins or packaging); If there is oil stains on the surface of the component, it can be lightly wiped with a cotton swab dipped in anhydrous ethanol, completely dried before further processing.
Drying treatment: Moisture is the main cause of component damage (such as pin oxidation, circuit board short circuit), and thorough drying is necessary:
Ordinary components: placed in a ventilated and dry place to air dry naturally (avoid direct sunlight);
Precision components/damp components: Place them in a drying oven at 40-60 ℃ for 2-4 hours (temperature should not be too high to avoid plastic shell deformation and internal capacitor failure);
Short term storage (<3 months): can be paired with silica gel desiccant (5-10g per 1L package); Long term storage: Prioritize using molecular sieve desiccants (with stronger moisture absorption capacity and less susceptibility to saturation).
Sealed isolation: Immediately seal after drying to block contact with air, moisture, and dust
Small components (resistors, capacitors, chips, connectors): Encapsulate in anti-static vacuum bags (electronic components need to be anti-static to avoid static breakdown of the chip), squeeze out the air inside the bag before packaging, and if necessary, fill it with nitrogen gas (inert gas to further prevent moisture and oxidation);
Medium sized components (relays, contactors, sensors): Place them in a sealed box (preferably made of PP/ABS material to prevent metal box oxidation and corrosion), lay desiccants inside the box, and seal the box mouth with a sealing strip;
Large components (transformers, motors, circuit breakers): When they cannot be completely sealed, cover them with dust-proof and moisture-proof covers, place sufficient desiccants inside the covers, and strictly control the humidity of the storage environment.
Regular maintenance: Even if stored in a sealed manner, regular inspections are necessary to avoid desiccant saturation and seal failure
Short term storage (<6 months): Check once every 1-2 months, replace saturated desiccants (silica gel desiccants become saturated when they change color), and confirm that the seal is not damaged;
Long term storage (≥ 6 months): Check once every 3 months. For precision electronic components, open the sealed bag for sampling (such as using a multimeter to measure resistance and capacitance values). For motors, transformers, etc., they can be regularly powered on to prevent moisture.
2、 The detection process before "activation" after long-term disuse (key steps)
Even if the protection is in place, it needs to be tested before use to avoid malfunctions:
Appearance inspection: Check for damage, rust, bent pins, dust accumulation, and whether the seal is intact;
Insulation testing: For high-voltage components and coil components, measure the insulation resistance with a megohmmeter (such as motor winding to ground insulation resistance ≥ 1M Ω, transformer winding insulation resistance ≥ 10M Ω). If it is lower than the standard, it needs to be dried;
Electrical performance testing: Use a multimeter to measure the nominal values of resistance and capacitance, the contact conduction resistance of relays/contactors (should be ≤ 0.1 Ω), and the static voltage of key pins of the chip (compared to the standard values in the datasheet);
Trial operation: For motors, transformers, etc., run them without load for 30 minutes first, and monitor whether the temperature, noise, and vibration are normal; Connect the control components (such as sensors and relays) to the test circuit to verify their functionality.