Juniper QFX3500, Техническая документация

Страница: 266 / 669

Prevention of Electrostatic Discharge Damage
Device components that are shipped in antistatic bags are sensitive to damage from static electricity. Some
components can be impaired by voltages as low as 30 V. You can easily generate potentially damaging
static voltages whenever you handle plastic or foam packing material or if you move components across
plastic or carpets. Observe the following guidelines to minimize the potential for electrostatic discharge
(ESD) damage, which can cause intermittent or complete component failures:
•
Always use an ESD wrist strap when you are handling components that are subject to ESD damage, and
make sure that it is in direct contact with your skin.
If a grounding strap is not available, hold the component in its antistatic bag (see Figure 61 on page 243 )
in one hand and touch the exposed, bare metal of the device with the other hand immediately before
inserting the component into the device.
WARNING: For safety, periodically check the resistance value of the ESD grounding
strap. The measurement must be in the range 1 through 10 Mohms.
•
When handling any component that is subject to ESD damage and that is removed from the device,
make sure the equipment end of your ESD wrist strap is attached to the ESD point on the chassis.
If no grounding strap is available, touch the exposed, bare metal of the device to ground yourself before
handling the component.
•
Avoid contact between the component that is subject to ESD damage and your clothing. ESD voltages
emitted from clothing can damage components.
•
When removing or installing a component that is subject to ESD damage, always place it component-side
up on an antistatic surface, in an antistatic card rack, or in an antistatic bag (see Figure 61 on page 243 ).
If you are returning a component, place it in an antistatic bag before packing it.
242