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Electric Signs

Superior Signmaking

Properly employed components underpin quality work.



Programming a product’s lifespan is part of the modern manufacturing process. In any field – tires to neon-sign transformers – marketplace pressures drive programmed obsolescence. Buyers want a quality product at a low price. Such demands drive manufacturers to produce quality appliances, at a reasonable cost, to meet their customer’s expected standards. These policies dictate that the produced items, if operated at 100% capacity, will survive slightly longer than the manufacturer’s warranty period.

If you employ a ballast or transformer at its highest load rating, you may reduce the appliance’s life expectancy to the manufacturer’s lowest expectation. Think about it. Manufacturing engineers design their products to meet certain specifications and then offer accompanying warranties to meet the specifications. Sign ballasts and transformers, when employed at the maximum load, tend to function slightly longer than the manufacturer’s warranty period. In the manufacturer’s view, this produces an acceptable product while reducing warranty returns.

So, how do you get more life out of a transformer or ballast? Stay within the designed load range, that is, load the transformer or ballast at roughly 80% of its stated maximum rate.

If you study a standard neon chart, for example, you’ll read that, using a 15,000V transformer, the maximum footage (load) for 15mm, mercury-filled tubing is 72 linear ft. Meaning, without fail, a 15,000V transformer will light up 72-ft. of this type tubing. However, if you apply the entire 72-ft. load, you’re maxing out the transformer and thereby limiting its lifespan to the warranty term.

Similarly, if you install a six-lamp ballast for six, 96-in. (48-ft.) fluorescent lamps, expect the ballast to meet its warranted life expectancy, but, like the neon example above, maximizing the load shortens the ballast life.

Some sign company executives prefer to maximize transformer and ballast use. They view it as a designed obsolescence factor and plan for profits from future service calls. I don’t agree with such policies and ask if such a company would hold the same view when negotiating a lease or maintenance agreement.


Let’s do some costing: 57 ft. is 80% of the maximum tubing footage (72 ft.) for a 15,000V transformer, as explained above. This is equivalent to purchasing a 12,000V transformer for its maximum load (55 ft.), at a cost increase of approximately $2.50 per transformer. Add another $2.50, or $5 total to the transformer’s price, to cover shop expenses. Three transformers fixed for long-life use would cost you an extra $7.50 and your customer another $15, which is minimal when compared to the cost for replacing a failed transformer after the warranty’s expiration date.

The same theory applies to ballasts. Using a ballast at 80% of its load capacity offers your customer a longer-lasting product at minimal added expense.

Therefore, keeping your customer’s service expenses in mind, consider an estimating policy that allocates 80% or less load for all ballast and transformers, so that your customer will receive maximum transformer/ballast performance for the money.

Adding life

Another way to lengthen ballast life is to place it in a raceway that lies above the sign-cabinet floor. True, it’s easier and less costly to place ballasts on the floor, but that’s where the water goes. You know that electricity and water don’t mix, so why risk it? I’m sure many of you will say, “I’ll just double nut the ballast,” thus lifting it above the floor and separating it from any collected water. This works, but, in doing so, you lose a valuable heat sink.

I prefer to position a ballast raceway between the lamps. Also, I place the ballast on its side, to keep the label away from accumulated grime, making it easier to read later. Some ballast manufacturers print the warranty-termination date on paper labels, which they glue to the ballast cowling. Water, dirt or debris can fade these labels, or they’ll detach from the ballast to decompose on the cabinet floor.


To protect a paper label, have your fabricator affix a strip of clear, 2-in.-wide packaging tape over it. The clear tape holds the label in place while restraining decaying elements, thus assuring your service people of easy reading during future service calls.

A lamp failure can also affect a ballast. For example, one failed lamp can harm the ballast of a six-lamp sign properly equipped with a six-lamp ballast. Typically, six-lamp ballasts have two circuits, one per three-lamp loop. If one circuit drops a lamp, the entire load goes off center, because ballasts require a specific load when wired for a specific amount of lamps. Diminish the load, and the ballast may become damaged.

Heat sinks

A corrugated heat sink, installed between the ballast and the cabinet floor or wall, also extends ballast life. Suppliers don’t offer such an item, so we make them ourselves. We cut a piece of corrugated sheet metal (steel or aluminum), to match the ballast’s length, and then install it between the ballast and cabinet floor. It makes a great heat sink and creates a channel, or tunnel, for the primary and secondary wires.

You can rig a transformer similarly by resting it on a corrugated heat sink placed at the bottom of a channel-letter raceway. Place it flush against the raceway’s back wall, allowing the cabinet to also act as a heat sink.

Note, additionally, that we mount a transformer with the secondary connections as far as possible from the raceway’s back wall.


Also, check the location’s primary voltage when installing these kinds of signs. Improper voltage can nega¬tively affect ballast and lamp life. Also, ground the display securely.

Lower-voltage transformers

Lower-voltage transformers are less likely to short. Because power always searches for ground, more applied voltage gives the power more chances to succeed. Notice, for example, when servicing neon signs, that almost all of the failed secondary wiring extends directly from the transformer to the first neon unit, because the highest voltages are those closest to the transformer. Use a smaller transformer to reduce the ground chances.

Some years back, my company obtained a contract to remove and replace some old Holiday Inn signs. We had serviced these signs for years and had few calls in light of how much neon tubing and transformers were involved. (The majority of our service records showed broken neon due to vandalism or weather and few secondary electrical problems.)

In the exchange process, we noticed the 20-year-old signs had their original transformers. We also saw they were smaller transformers, often less than 7,500V. Remarkably, the signs were fair-sized, neon displays, and these details proved to us that lower-voltage transformers relate to reduced transformer and neon failure.

Similarly, while recently servicing a Firestone Tire sign our shop had installed in the ’80s, we again proved our conservative transformer principles. After having inspected the Firestone installation’s 80, original transformers (four channel-letter elevations, comprising 20 or more transformers at each elevation), we discovered only two had failed. The Firestone sign’s self-contained, neon letters had small (4,000V) PBKM (contained-housing) transformers.

As you can see, many techniques help insure a longer life for sign ballasts and transformers, and I’m sure other examples abound.

Finally, when establishing your shop’s quality goals, remember that component life impacts the sign’s final quality rating, because, even though a customer’s analysis always includes a competitive pricing evaluation, his or her long-term, after-purchase viewpoint ultimately determines your product’s worth.




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