EM TEST
UCS 500 Series
Operating Manual
V 5.40
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12.2. Ring wave pulse generation
Discharge switch:
The discharge switch is a highly reproducible semiconductor switch.
12.3. Coupling/decoupling network
The coupling network has to couple the interference pulses to the lines of a power supply system (AC or DC).
Capacitive coupling is the specified coupling mode for surge testing.
12.3.1.
Coupling to ac/dc power supply lines
The surge generator UCS 500 has an integrated coupling network in accordance with IEC 61000-4-12. It must be
possible to test with different coupling modes:
Line
GND or
Neutral
GND or
L + N
GND or
Line
Neutral
Coupling Line to Line
Coupling Line to Earth
The release of the surge pulses is mostly related to a certain phase angle.
The surge pulses are synchronized to the input signal at the rear Sync-connector.
Attention:
The decoupling part of the coupling/decoupling network includes some capacitors for filtering of 20
F
related tp protective earth (chassis of the generator). This is to be conform with the requirement of IEC 61000-4-5
concerning attenuation of the surge transients in direction to the power mains supply input of the CDN.
As consequence there will exist an increased current to PE (protective earth) which might be hazardous to the
operator in case of a failure or wrong installation. Therefore it is very important to take the following points into
account before setting the generator into full operation.:
12.4. Test set-up
According to the specifications of IEC 61000-4-12, the ring wave generator has a source impedance of 12 ohm
when the simulator is coupled between the lines and protective earth.
Therefore it is important
- not to disconnect the surge simulator form protective earth (power cable)
- to have an installation where the simulator is connected via its ground reference connector to earth
1.
Due to this increased current into the PE system no earth fault current protectors can be used within
a surge testing area.
2. As consequence the surge generator shall be connected always to Protective Earth, even if no test is
conducted.
via plugged in power mains supply cable including the PE wire!!!!!!
via plugged in EUT power mains supply at the rear side of the generator, including the PE wire !!!!
via Ground Reference Connector, screwed to the chassis of the generator.
These measures result in double safety in case of a fault
