Technical Reference
Manual-XPM3m Revision Date: August 2014
ELECTRICAL POWER & COMPUTER
CAUTION:
WHEN THE OVEN IS “OFF”, MANY PARTS OF THE OVEN MAY BE ELECTRICALLY POWERED AND
DANGEROUS
ELECTRO - STATIC DISCHARGE PROCEDURES ( ESD)
When any electronic PC board or any semiconductor device is to be handled, an antistatic wrist strap and an
antistatic work surface or mat must be used to reduce the possibility of causing damage to electronic components
on the PC board.
Semiconductor devices are sensitive to static electricity which can reach potentials of 20,000 volts or more.
Static electricity may reach 3000 volts before it can be felt ! If the discharge (spark) is visible, it is probably in
excess of 5000 volts!
The current in static electricity is low. The component is usually weakened by the static damage, but does
not fail immediately. This causes intermittent problems, which can be very difficult to isolate. Static electricity can
also cause immediate failures on boards and components. Static failures from improper handling and packing can
mask the original problem from a repair person so that when you receive a board back from a repair facility, you end
up with the same problem you had before the repair.
Any clothing made with synthetic fibers is capable of generating static electricity
. Any clothing can insulate
a wrist strap from your skin. The purpose of the strap is to discharge static electricity that has been built up on your
body in a controlled manner to prevent personal injury and damage to the equipment involved.
As long as you are properly connected to the oven ground by the antistatic wrist strap, you will be at the
same potential, as the oven and the risk of damaging the components with static electricity will be reduced.
When a board with electronic components on it is removed, it is important to remain connected to the oven.
When the board has been completely removed from the oven, it may be placed on top of the antistatic mat
(connected to the oven).
The board should be put into an antistatic bag while you are still connected to the oven. The bag should be 'sealed'
before disconnecting yourself from the oven ground.
Some antistatic bags are made of plastic that is coated on the inside with a thin conducting metallic film. This film
turns the bag into a “Protective Shield” surrounding its contents with a path for electricity to follow, thus preventing
damage to the contents when it is completely closed. (Torn bags should be discarded.).
The bags can hold a static charge on their outside surfaces. Always properly ground yourself and have a
properly connected antistatic work surface to rest the bag and contents on before opening an antistatic bag.
When replacing a PC board or electronic component, always be properly grounded until finished with the
repair or replacement procedure. Always be properly grounded to the oven that is being worked on.
Not all ovens
are at the same ground potentials.
All electronic boards and components must always be properly protected from static electricity and properly
stored.
