Gamry Instruments EIS Box, Operator'S Manual, Page: 10 / 52

Safety Considerations
10
Most electrochemical cells are isolated from earth ground, so isolation of the EIS Box from earth is not required.
In these cases, connection of the EIS Box chassis to
System Ground may lower the noise seen in an
electrochemical test.
The System Ground is the common voltage reference point for the EIS Box’ s circuitry. It floats with respect to
the Protective Ground .
The System Ground binding post is not intended for any use other than connecting the EIS Box to an earth
ground to improve shielding against noise. Connecting this binding post to a hazardous voltage can create a
significant safety hazard.
The EIS Box contains surge suppressors that limit the voltage difference between the EIS Box’s chassis ground
and earth ground to about 28 V. These surge suppressors are not part of the safety mechanisms in the EIS Box.
Instead they are present to limit the possibility of improper instrument operation or instrument damage due to
electrostatic discharge (static electricity) and other surge events such as lightning.
Warning:
Never connect the Protective Ground and System Ground if the
electrochemical system you are testing is earth-grounded. Two earth-ground connections in a high-energy
electrochemical system can create hazardous conditions.
Warning:
Do not connect the Protective Ground binding post to any voltage other than
earth ground. An improper connection can create a safety hazard, which could result in personal injury or
death.
Warning:
Do not negate the protection of the EIS Box’s earth ground by any means. Do
not use the EIS Box with a two-wire extension cord, with an adapter that does not provide for protective
grounding, or with an electrical outlet that is not properly wired with a protective earth ground. If the
protective ground is not properly connected, it creates a safety hazard, which could result in personal injury
or death.
Sources of earth ground include
• Most metal water pipes,
• The chassis of most electronic apparatus (which are generally earth-grounded), and
• The protective ground terminal of an AC mains power plug.
We recommend that you discuss grounding with an electrical or electronics professional prior to making this
earth-ground connection.