A useful initial step to eliminate enclosure moisture is to characterize the enclosure environment using a temperature/humidity data logger. These inexpensive, battery-powered devices (~$200) record Dry Storage Cabinets. They also indicate the dew-point conditions inside the enclosure (Fig. 6). Maintaining enclosure temperatures above dew-point temperatures is a necessity for condensation prevention.
Pursuing this alternative can be accomplished in a number of ways, which range from desiccant to thermoelectric dehumidifiers-the challenge is to select an alternative that is certainly inexpensive to both implement and sustain. The water-absorption capability of desiccant is influenced by a variety of factors (e.g., desiccant type, humidity, temperature). For instance, silica gel can absorb approximately 40% of their weight in water. A 4’ x 6’ x 2’ electrical enclosure in a hot/humid environment would saturate 125 g of desiccant in about two air exchanges. Therefore, the resulting frequency of required desiccant change-outs (which affects maintenance costs) is basically driven by how well the enclosures are sealed. Unfortunately, in terms of desiccant regimes, each act of opening an enclosure to examine the desiccant may serve as an air exchange.
Dehumidifiers are comparatively cheap, although finding convenient available power inside an enclosure may be problematic. The positive feature is the fact dehumidifiers remove the manual intervention connected with a desiccant regime. The negative feature of dehumidifiers is because they introduce an additional device that can ultimately fail.
Another method is to minimize the potential for condensation through internal heaters (or light bulbs) to maintain the interior enclosure temperature well above dew-point temperatures. The downside is the fact that higher temperatures may be detrimental to some heat-sensitive electronic components, as well as the higher temperature actually allows the air to hold more moisture. Venting and fans can aid in avoiding condensation in certain situations-although the Dry Storage Cabinets For Optics still exists. One interesting product the makers of GORE-TEX® have produced involves screw-in vents that enable enclosures to breathe, while providing a barrier to moisture and contaminants. The theory behind this type of venting is it reduces the stress on door seals when you will find pressure differentials in between the enclosure and the environment. By equalizing pressure, the potential of moist air at higher pressure defeating your door seals is lessened.
Moisture-hardening of electronics includes many different techniques. When it comes to connectors, using waterproof connectors or hardening existing connectors and splices with heat-shrink tubing can be useful to reduce water intrusion and corrosion. Avoiding horizontal orientation of components like printed circuit boards in the enclosure can minimize surfaces where condensation may collect for extended amounts of time. Conformal coatings for lower-voltage printed circuit boards and the usage of potting (see Fig. 7) of higher-voltage components greatly raise the moisture resistance of components. Potting costs vary in accordance with the dimensions of order, material selection jmmhra part geometry, but representative costs for really small orders (lower than 10) typically fall inside the range of $18 to $45 per part. Yet another benefit from potting is the added defense against shock and vibration.
Moisture protection of electronics is most beneficial approached by pursuing practices that maximize Desiccant Dry Cabinets during equipment installation, along with being willing to mitigate failure through anyone moisture-protection measure during operations. This plan, in addition to tracking equipment-maintenance performance to comprehend how well moisture-protection measures work, can lead to long-term minimization of electronics moisture-induced problems. MT.