ZEISS
2 Requirements | 2.3 Mains Connection
Fig. 3: Overvoltage Categories explained
Category
Description
I
For connection to circuits in which measures are taken to limit transient
over-voltages to an appropriately low level.
Examples: Protected electronic circuits.
II
Energy-consuming equipment to be supplied from the fixed installation.
Examples: Appliances, portable tools, and other household and similar
loads. Measurement equipment intended to measure the voltage levels of
these loads must be rated at this overvoltage category.
III
In fixed installations and for cases where the reliability and the availability
of the equipment is subject to special requirements.
Examples: Switches in fixed installation and equipment for industrial use
with permanent connection to the fixed installation; measurement equip-
ment intended to measure the voltage levels of these fixed installations
must be rated at this overvoltage category.
IV
Used at the origin of the installation.
Examples: Electricity meters and primary overcurrent protection equip-
ment.
Installation Requirements ZEISS LSM 900 | en-US | Rev. 2 | 349500-8183-000
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