6. The potential at anypoint shouldnot exceed 0.75 volts RMS. A
leakage current tester (Simpson Model 229 or equivalent) maybe
used to make the hot checks, leakage current must not exceed 1/2
milliampere. Incase ameasurement isoutside of the limits
specified, there isapossibilityof ashock hazard, and the
equipment shouldbe repaired and rechecked before itisreturned
to the customer.
2. Prevention of Electrostatic Discharge (ESD) to
Electrostatic Sensitive (ES) Devices
Some semiconductor(solidstate) devices canbe damagedeasilybystatic electricity. Such
components commonlyare calledElectrostatic Sensitive (ES) Devices. Examples of typical ES
devices are integratedcircuits and some field-effect transistor-sandsemiconductor"chip"
components. The following techniques shouldbe usedtohelpreduce the incidence of
component damage causedbyelectrostatic discharge (ESD).
1. Immediatelybefore handling anysemiconductor component or
semiconductor-equipped assembly, drainoff anyESDon your
bodybytouching aknownearth ground. Alternatively, obtainand
wear acommerciallyavailabledischarging ESDwrist strap,
whichshouldbe removed for potential shock reasons prior to
applying power to the unitunder test.
2. After removing an electrical assemblyequipped with ES devices,
place the assemblyon aconductive surface such as aluminum
foil, to prevent electrostaticcharge buildup or exposure of the
assembly.
3. Use onlyagrounded-tipsoldering iron to solder or unsolder ES
devices.
4. Use onlyan anti-staticsolder removal device. Some solder
removal devices not classified as "anti-static(ESDprotected)"
can generate electrical charge sufficient to damage ES devices.
5. Donot use freon-propelled chemicals. These can generate
electrical charges sufficient to damage ES devices.
6. Donot remove areplacement ES device from its protective
package until immediatelybefore you are readyto install it. (Most
replacement ES devices are packaged with leads electrically
shorted together byconductive foam, aluminum foil or
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