Edwards TCU 40/80 - Page 31

7.2 Hazards
Table 9 gives the classifications of electrical hazards. This number indicates the severity of the hazard as
defined by SEMI S2-93.
Table 9 - Electrical hazards classifications
Classification
Typel
Type 2
Type 3
Type 4
Type 5
Description
Equipment is fully de-energized.
Equipment is energized. Live circuits are covered or
insulated. Work is performed at a remote location to
preclude accidental shock.
Equipment is energized. Live circuits are exposed and
accidental contact is possible. Potential exposures are less
than 30 volts RMS, 42.2 volts peak, 240 volt-amps, 20
Joules. (See NFPA 79-14.3, IEC 204, UL 1950 & 1262, IEC
950.)
Equipment is energized. Live circuits are exposed and
accidental contact is possible. Potential exposures are greater
than 30 volts RMS, 42.2 volts peak, 240 volt-amps, 20
Joules or radio frequency (rf) is present.
Equipment is energized and measurements and adjustments
require physical entry into the equipment, or equipment
configuration will not allow the use of clamp-on probes.
Comment
None called out.
None called out.
Called out as Type 3.
Called out as Type 4.
None called out.
TCU 40/80 Temperature Control Unit
25