Black Box Version 1.0 user manual Protection against dangerous affects, Surge safety

10.2.1 Protection against dangerous affects

The protection of the equipment against dangerous interfering affects meets the requirements of ITU-U K20/K.21

10.2.2 Surge safety

Parameter	Description	Note
The resistance between the
ground terminal and isolated parts
of the device	≤ 0,1 Ohm
Insulation resistance of the device	≥ 20 MOhm (normal climatic
electrical circuit	conditions)
	≥ 5 MOhm (high temperature)
	≥ 1 MOhm (high humidity)
Test voltage for ungrounded	500 V (amplitude, normal
electrical circuit relative to the	climatic conditions)
case of the device	300 V (amplitude, high
	humidity)
Test voltage of isolation of	500 V (amplitude, normal	Without
electrical circuit, galvanically	climatic conditions)	discharge
disconnected with the ground	300 V (amplitude, high	within 1
	humidity)	minute
Test voltage of 50 Hz accepted by	> 2000 Vrms relative to	Within 2 s
the line interface	ungrounded device elements
	> 1500 Vrms relative to
	grounded device elements

10.3 10.3 Climatic conditions

The units are engineered to operate in the following climatic conditions:

•air temperature -5… +45°C;

•relative air humidity 95% at 25°C.

The equipment preserves all its characteristics at 450 Torr (60 KPa)

The storage conditions: -50…+50°C.

The equipment can withstand all means of transport (including airplanes), i.e. it withstands the 90-Torr (12 KPa) atmospheric pressure at -50°C.

Version: 1.0 Page. 82 of 95