R&M Data Center Handbook

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Stress conditions for Classes E1 to E3 in accordance with the MICE table from EN 50173-1
Immunity against high-frequency radio waves
The test outlined in EN 61000-4-3 serves to examine the immunity of the equipment under test (EUT) against
radiated electromagnetic fields in the frequency range from 80 MHz to 2.0 GHz. This test simulates the influence
of interferences such as radio broadcast and TV transmitters, mobile phones, wireless networks and others.
The transmitting antenna was set up at a distance of 3 m from the EUT, which was then irradiated from all four
sides. The field strength, measured at the location of the equipment under test, was selected in accordance with
the MICE table (Figure, “Radiated high frequency”).
Results in accordance with EN61000-4-3 (left) / Operational test of a mobile phone (right)
All shielded cabling variants are well suited for 10GBase-T operation in offices and light industrial areas. For
harsher industrial areas, an additional overall braided shield (S-FTP design) is necessary. Single- or double-sided
grounding has no influence on the immunity against external radiation. A good unshielded cabling is suitable for
1000Base-T in offices and areas used for light industry. For the use of 10GBase-T with unshielded cabling, however,
additional protective measures are necessary; e.g. metallic raceway systems and/or additional separation
away from the sources of interference.
An additionally performed operational test confirmed the high sensitivity of the unshielded systems to wireless
communications equipment in the 2 m to 70 cm band when operating with 10GBase-T. If a personal radio or
mobile phone was operated at a distance of 3 m (see Figure above), with unshielded cabling there was an
interruption in the data transmission, while all shielded systems experienced no impairment of the transmission.
Immunity against interference due to power cables
A test in accordance with EN 61000-4-4 was carried out in order to check the immunity of the equipment under
test (EUT) against repeated, fast transients as produced by the switching of inductive loads (motors), by relay
contact chatter and by electronic ballasts for fluorescent lamps. In order to achieve reproducible coupling between
the power cable and the EUT, a standardized capacitive coupling clamp was used in this test. The disturbances
overed voltage peaks of 260 - 4000 V with a wave shape of 5/50 ns and a separation of 0.2 ms. The voltage levels
in accordance with the MICE table were applied (see Figure, “Fast transient (burst)”).
Page 152 of 156 © 08/2011 Reichle & De-Massari AG R&M Data Center Handbook V2.0