Electro Static Discharge (E.s.d.); What Is It? What Does It Do; Avoiding E.s.d. Damage; What About Wrist Straps And Special Mats - Jacuzzi LED Series Troubleshooting Manual

2.0 Electro Static Discharge (E.S.D.)

2.1 E.S.D. - What is it? What does it do?
Static electricity is always being generated around us, even at those times of
the year when we no longer get zapped after walking across a rug and touching
something.
Like all state-of-the-art circuit boards, the hot tubs circuit board can be damaged by unnoticed static
electricity. Damaged is the key word. Sometimes a board which has been subjected to E.S.D. will fail
immediately upon being put back into service.
• 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 is 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 loses its reputation for quality.

2.2 Avoiding E.S.D. Damage

We can't prevent static charges from building up within our bodies 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 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) remove the replacement board from the static
protective bag, C) lay the replacement board on the ground,
D) place the bad board in the bag from which you removed
the replacement board, E) return bad board(s) 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 to drain into ground any static charges which might build up. Proper use
of the wrist strap and special mat guarantees maximum protection against E.S.D. 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 E.S.D. 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 grounding lug or heater 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. Touching a finger to the grounding lug or heater immedi-
ately before removing the good board from the bag will drain any 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 or heater before picking up the bad board will again
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 or heater before picking up the good board will again
drain any charges built up by the rustling of your clothes. In the process of installing the replace-
ment board, you and the board will be grounded to the load box, grounding lug, or heater, draining off
charges you may build up during installation.
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