|
| |
How to Make a Shelf
or Cart ESD Safe |
| |
- Start with a metal shelving unit with metal legs
- Make sure the shelves and legs are conductive (they
should be chrome or stainless)
- Painted, plastic or powder coated metals are
insulators and are difficult to make ESD safe
- Pick one or more posts to be a "grounding post" for
your ESD shelving
- Connect the metal shelf to the metal grounding post(s)
- Connect the metal post(s) to ground using a
conductive floor (ESD floor)
- If you don't have an ESD floor or your floor is
unreliable, connect the shelf to
a common ground (typically tied to an or earth ground or electrical
ground) using an
ESD Clip +
Ground Point
For a Mobile ESD Cart
- Add one or more Conductive wheels to the cart to
connect the cart to ground through the conductive floor (see diagram
below)
- Optional: to assure that a cart is grounded
while at rest, connect a ground wire between the cart and an ESD
ground when the cart is stationary using an
ESD Clip +
Ground Point
|
| |
|
| |
|
|
Minimum requirements
OR, for a mobile cart
-
Use an
ESD Wheel (conductive wheel) for grounding a mobile ESD safe
cart
-
Optional: to assure that a cart is grounded
while at rest, connect a ground wire between the cart and an ESD
ground when the cart is stationary using an
ESD Clip +
Ground Point
|
 |
|
|
|
|
Better..
2
ESD grounding posts
- One post connection per shelf using
ESD ClipTM or metal split sleeve
- Add one extra connection to a 2nd "grounding post"
- TWO connections to the ESD floor are provided by the
Two "grounding posts" contacting the conductive floor
OR, for a mobile cart
-
Use Two
ESD Wheels (conductive wheels) for grounding a mobile ESD safe
cart
-
Optional: to assure that a cart is grounded
while at rest, connect a ground wire between the cart and an ESD
ground when the cart is stationary using an
ESD Clip +
Ground Point
|
 |
|
|
|
|
|
Best..4 ESD grounding posts
- TWO post connections per shelf using
ESD ClipTM or metal split sleeve
provides redundant connections to each shelf
- FOUR connections to the ESD floor are provided by
the FOUR "grounding posts" contacting the conductive floor
OR, for a mobile cart
Optional: to assure that a cart is grounded
while at rest, connect a ground wire between the cart and an ESD
ground when the cart is stationary using an
ESD Clip +
Ground Point
|
 |
|
|
|
|
|
|
|
Summary
If you are
considering conductive wheels, you have probably concluded that your "drag
chains" or "grounding cables" are not working well for you. Conductive
wheels are more reliable and less prone to corrosion and
contamination than drag chains or cables.
While even 4 conductive wheels or posts will not
provide a good connection to a dirty or non-functioning ESD floor, more
connections means a higher probability of making a successful
connection. With only one leg / wheel, you only have
one possibility for connection. All it takes to disrupt the ESD
ground connection is to move the cart onto a small scrap of paper or
plastic or perhaps move the leg onto a place on the floor that is not
conductive. In this case, more is better.
|