HBM GN610, GN611 Technical Note

Technical Note

English

HBM public

GEN series 1 kV Input
Cards GN610 and GN611

Isolation and Type
Testing

GN610, GN611 Isolation and type testing

1 International standards for test equipment safety

1.1

Measurement categories

l

The international standards for test equipment safety are the IEC 61010-1
and the IEC 61010-2-030.

l

IEC 61010-1 defines three overvoltage categories (CAT II, CAT III, and
CAT IV) on the power supply side of an instrument.

l

IEC 61010-2-030 defines three measurement categories (CAT II, CAT III,
and CAT IV) on the measurement input side of an instrument, for
measurement inputs which can be directly connected to mains.

l All measurement inputs, which are not specified to be connected to mains,

have no CAT rating and are referred to as O (like

Categories according to IEC 61010-2-030:2010

Electrical equipment, specifically measurement tools can according to IEC
61010-2-030:2010 be assigned into 4 categories. These measurement
categories are indicated with the terms O (previously CAT I), CAT II, CAT III
and

CAT IV. Originally these categories are used to indicate the overvoltage or
surge voltage that is likely to occur and can be sustained by the equipment.
Actually the category indicates the amount of energy that can be released in
the event of a short circuit. 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 mains. Think of measurement of: signal levels,
regulated low voltage circuits or protected secondary circuits. For this category
there are no standard over voltage or surge impulse levels defined.

Others).

CAT II: This category is for measurements directly connected to low-voltage
mains. Think of measurement of: mains sockets in household applications or
portable tools. This category is expecting to have a minimum of three levels of
over current protection between the transformer and connection point of the
measurement. (See Figure 1.1).

CAT III: This category is for measurements directly connected to the distribution
part of a low-voltage mains installation. Think of measurement of: circuit
breakers, wiring, junction boxes etc. This category is expecting to have a
minimum of two levels of over current protection between the transformer and
connection point of the measurement. (See Figure 1.1).

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GN610, GN611 Isolation and type testing

CAT IV:

a low-voltage mains installation. Think of measurement of: over current
protection devices, ripple control units etc. This category is expecting to have
a minimum of one level of over current protection between the transformer and
connection point of the measurement circuit. (See Figure 1.1).

Figure 1.1: Category indication according to IEC 61010-2-030:2010

This category is for measurements directly connected to the source of

Example:
voltage 1000 V DC.

Table 1.1: Insulation test voltages according to IEC 61010

Nominal Voltage
(V RMS or V DC)

≤ 150

> 150 ≤ 300

> 300 ≤ 600

> 600 ≤ 1 000

Using the above table one can deduct that this specification informs the user
the device passed the insulation tests;

4.000 V. The maximum operating input voltage is 1000 V DC. This device is to
be used to measure CAT II circuitry up to 600 V.

A measurement device is specified as 600 V CAT II, maximum input

-2-

030:2010

IEC 61010-2-030:2010

5 sec. AC test (V RMS) Impulse test (V)

CAT II CAT III CAT IV CAT II CAT III CAT IV

840 1.390 2.210 1.550 2.500 4.000

1.390 2.210 3.310 2.500 4.000 6.000

2.210 3.310 4.260 4.000 6.000 8.000

3.310 4.260 6.600 6.000 8.000 12.000

5 sec at 2.210 V RMS and impulse

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GN610, GN611 Isolation and type testing

WARNING

Measurement inputs of this instrument should not be used to measure
high-energy signals of measurement categories
CAT IV (IEC 61010-2-30:2010) (e.g. mains measurements) , unless
specifically stated for the specific input.

CAT II, CAT III or

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GN610, GN611 Isolation and type testing

1.2 Basic versus reinforced insulation

For reference below one can find the basic insulation and supplementary
insulation as well as the reinforced insulation test values for CATII.

Table 1.2: Test voltages for testing electric strength of solid insulation in
measuring circuits of measurement category II (IEC 61010

-2-

30:2010)

Nominal
voltage line to
neutral a.c
r.m.s. or d.c. of
MAINS being
measured. (V)

≤ 150

> 150 ≤ 300

> 300 ≤ 600

> 600 ≤ 1000

To protect a user from hazardous voltages there are several means of
protection possible. As one can see below basic insulation + supplementary
insulation is a possibility but also reinforced isolation is a means of protection.
The test voltages are different per means as can be found in the above table.

Test voltage

5 s a.c. test V a.c. r.m.s. Impulse test V peak

Basic
insulation and
supplementary
insulation

840 1390 1550 2500

1390 2210 2500 4000

2210 3510 4000 6400

3310 5400 6000 9600

Reinforced
insulation

Basic
insulation and
suplementary
insulation

Reinforced
insulation

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GN610, GN611 Isolation and type testing

Additional means of protection in case of single fault conditions

Accessible parts shall be prevented from becoming HAZARDOUS LIVE IN
SINGLE FAULT CONDITION. The primary means of protection (see
Figure 1.2) shall be supplemented by one of A, B, C or D. Alternatively one of
the single means of protection E or F shall be used. See Figure 1.2

.

Figure 1.2: Acceptable

Example: A measurement device is specified as 600 V CAT II reinforced
insulation, maximum input voltage 1000 V DC.
Using the above information one can deduct that this specification informs the
user that the measurement device is tested on input to chassis ground 5 s at

3.510 V RMS and impulse 6.400 V. The maximum operating input voltage is
1000 V DC. This device is to be used to measure CAT II circuitry up to 600 V.

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arrangement of protective means against electric shock

GN610, GN611 Isolation and type testing

2 GEN series 1 kV input cards GN610, GN611

2.1

Isolation and input of the GN610, GN611

An overview of the GN610, GN611 card isolation and input is given below (see
Figure 2.1). The isolation of the channel to chassis is 1000 V RMS and is also
qualified as 600 V CAT II (or 300 V CAT III). The common mode of the
differential input channel (isolated GND) can be 1000 V RMS with respect to
the chassis. If one channel has common mode at +1000 V and one at

-1000 V (with respect to chassis), the voltage between the two channels is
2000 V. The standards at which the card is certified is IEC61010-1:2010 and
IEC61010-2-30:2010.

Isolation

Input signal to chassis 1000 V RMS, 600 V CAT II (REINFORCED)

Channel to chassis 1000 V RMS, 600 V CAT II (REINFORCED)

Channel to channel 2000 V RMS, (BASIC)

Figure 2.1: Isolation 1kV card overview

l The isolation between channel and chassis is classified as

REINFORCED. This can be seen as double isolation, which is necessary
because the chassis might be accessible (conductive parts can be touched)
to users (personal safety).

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GN610, GN611 Isolation and type testing

l Isolation between channels is BASIC, since a channel is not accessible

and there is therefore no direct risk for a user (product safety).

l REINFORCED or DOUBLE isolation has higher test values than BASIC

isolation.

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