13 Jan

Encapsulating your scale circuit board electronics will increase your uptime

As an area sales manager for the (snowy) Denver region – plus years of experience installing truck and rail scales around the United States and the world – I have seen the effects of different climates on scale electronics. I have come to a firm belief in the necessity of encapsulating the main electronic components of truck and rail scales to make absolutely sure that the scale is impervious to moisture penetration. Fairbanks identified this need very early on as we shifted from the older mechanical truck scales to the full electronic lines of scales. We started about 15 years ago and continue in that belief to this day. Here’s why.

Why do scales need to be encapsulated?

The number one issue affecting electronics is the climate and weather in which the scale operates. Snow, ice, and water can have a major effect, as can temperature changes that produce condensation.

Besides these environmental factors, there are several human factors that play into the desirability of encapsulation. First is the potential for control boxes to get hit or damaged. Things like tightening and loosening of gland nuts, over-torqued cover bolts, vibration, and even physical damage to the enclosure can affect performance. Chipping away at that ice and debris can also damage components.

Secondly, the scales (both above and below ground) require regular cleaning. When operators clean scales they may use direct water pressure, and risk accidentally spraying directly on components. Encapsulating is a great safeguard for protecting the vital components of a truck scale.

I should mention that I recommend encapsulation for all truck and rail scale electronics and boards. For industrial scales, the need for encapsulation depends more on where the installation is taking place and especially if temperature changes are going to occur. For example, if the scale will be used with a tank weighing assembly, or with hoppers or bins located outside, one may really benefit by protection from the environment. Encapsulation can also benefit surge protection. The Fairbanks’ Intalogix™ system, part of scale instruments used with its scales, encapsulates its smart sectional controller (SSC) and pit power supply (PPS), protecting against dangerous power surges and lightning strikes. 

What will it cost you if you don’t encapsulate?

Now let’s talk about the costs of not encapsulating to protect the scale electronics. In a word, these costs are limitless – when the scale is down, the operation cannot use its cash register. The length of downtime has to include the response time for locating and scheduling a service technician. The total costs of this downtime can be considerable, depending on how many trucks are being run, the cost of the commodity, and the operation’s ability to use a secondary scale. In my experience, electronics is the main reason for truck scale downtime.

How are electronics encapsulated?

Encapsulation can be done with a variety of materials. At Fairbanks, we use a difunctional bisphenol A/Epichlorohynrin “epoxy” resin. The base is then cross-linked with an “amine” hardener blend. We chose this system because it has exceptional electrical insulating properties. It is also translucent, so you can see through the thick epoxy to spot any issues on the circuit board.

The epoxy formulation is a tried and true chemistry that has been used for decades. You can find it in tooling, casting and molding, electrical and aerospace applications, marine coatings for boat hulls, and chemical-resistant tank linings.

Depending on the operating environment, scale electronic encapsulation can last more than 20 years. When not encapsulated, the scale’s common structural steel may still be intact, but the electronics would likely fail long before they would on an encapsulated board.

The early encapsulation design Fairbanks pioneered in the early 2000s has been constantly improving through manufacturing innovations and real world experience. I regularly come across customers who have installed competitors’ equipment (or even Fairbanks pre-encapsulation equipment) and they recognize the long term benefit of providing encapsulation to their scales.

The scale is the cash register for businesses in many industries, so the ability to weigh things accurately day in and day out is vital. If the scale is not accurate or is out of service, costs can mount quickly. Encapsulating electronics will go a long way toward eliminating this costly downtime.

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