HBM GEN3i, Руководство пользователя, Страница: 28 / 1160

2.5 Protection and isolation
2.5.1 Measurement categories
l
The international standards for test equipment safety are IEC 61010
-
1 and
the IEC 61010
-
2
-
030.
l
IEC 61010
-
1 defines three overvoltage categories (CAT II, CAT III, and
CAT IV) for the power supply of an instrument.
l
IEC 61010
-
2
-
030 defines three measurement categories (CAT II, CAT III,
and CAT IV) for an instrument's input measurements which can be directly
connected to mains supply.
l
All measurement inputs which are not specified to be connected to the
mains power have no CAT rating and are referred to as O (like Others).
Categories in accordance with IEC 61010
-
2
-
030:2010
Electrical equipment, specifically measurement tools, can be assigned into four
categories in accordance with IEC 61010
-
2
-
030:2010. These measurement
categories are indicated by the terms O (previously CAT I), CAT II, CAT III and
CAT IV. Originally, these categories were used to indicate the overvoltage or
surge voltage that was likely to occur and could be sustained by the equipment.
Currently, the category indicates the amount of energy that can be released if
a short circuit occurs. A higher category number indicates a higher energy level
that can occur and can be sustained by the equipment.
O (Other) (previously referred to as CAT I ): This category is for measurements
not directly connected to a mains supply. Measurements for this category are
signal levels, regulated low voltage circuits or protected secondary circuits. For
this category, there are no defined standard overvoltage or surge impulse
levels.
CAT II : This category is for measurements directly connected to a low voltage
mains supply. Measurements for this category are mains sockets in household
applications or portable tools. This category expects a minimum of three levels
of overcurrent protection between the transformer and connection point of the
measurement. (See Figure 2.1).
CAT III : This category is for measurements directly connected to the distribution
part of a low voltage mains installation. Measurements for this category are
circuit breakers, wiring, junction boxes, etc. This category expects a minimum
of two levels of overcurrent protection between the transformer and connection
point of the measurement. (See Figure 2.1).
GEN3i
28 I3763-3.1 en HBM: public