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2.0 Electro Static Discharge
2.1 ESD - What Is It? What Does It Do?
Static electricity is always being generated around us, even at those times when we no
longer get zapped after walking across a rug and touching something.
Like all state-of-the-art circuit boards, the hot tub’s circuit board can be damaged by
unnoticed static electricity. Damaged is the key word. Sometimes a board which has
been subjected to ESD will fail immediately upon being put back into service. Usually
a board will operate for a few days, or months, then fail.
• If the hot tub runs only a few days, the customer thinks you provided poor service.
• If the hot tub runs only a few months, the customer thinks the circuit board was a low quality product.
• The customer loses use of the hot tub. You lose money because you must go back to make it right. Jacuzzi
Hot Tubs loses its reputation for quality.
2.2 Avoiding ESD Damage
We can’t prevent static charges from building up within us as we go about our jobs,
so we must do three things to protect circuit boards from getting zapped:
1. Never transport or ship circuit boards - good boards or bad boards - except in
the static protective bags.
2. Never remove the board from the static protective bag unless you are ready to
install it in the hot tub.
3. After removing the bad board from the hot tub, A) lay it on the ground, B) re-
move the replacement board from the static protective bag, C) lay the replace-
ment board on the ground, D) place the bad board in the bag from which you
removed the replacement board, E) return bad board(s) to Jacuzzi Hot Tubs in
undamaged sealed static protective bags.
2.3 What About Wrist Straps And Special Mats?
The purpose of these devices is to keep the technician, the work surface and the circuit board at the same electrical
potential, and drain into ground any static charges which might build up. Proper use of the wrist strap and special
mat guarantees maximum protection against ESD damage.
2.4 Must Wrist Straps And Mats Be Used When Replacing A Circuit Board?
No, if you keep the spare board in the protective bag during transport and you observe a few simple techniques
during replacement.
The possibility of ESD damage to the circuit board during replacement will be minimal because of the hot tub’s
design and the way you normally work on it. Touching the ground lug will drain all built-up static charges from
your body much like a wrist strap would. Laying the bad board on the ground will tend to keep it neutral. Touch-
ing a finger to the grounding lug immediately before removing the good board from the bag will drain charges
built up by the rustling of your clothes. Laying the good board on the ground after removing it from the bag will
tend to keep it neutral. Another quick touch of the grounding lug before picking up the bad board will drain built
up charges. Slipping the bad board into the protective bag will allow it to be transported safely. Another quick
touch of the grounding lug before picking up the good board will again drain any charges built up. In the process
of installing the replacement board, you and the board will be grounded to the load box or grounding lug, drain-
ing off charges you may build up during installation.
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Spa Light
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Circ Pump
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Rev. 3.53
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