Reo Elektronik REOTRON MDW 700, Руководство по эксплуатации

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REOTRON MDW 700
Operating instructions
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12.0 Putting into service
Safety Instruction
Qualified personnel only, are permitted to install electronic equipment
Because attenuation capacitors (Y-capacitors) are used, leakage current flows through the case to pro-
tective earth (PE). Therefore, units must be earthed.
12.1 Preliminaries
•
Check if the local supply voltage is the same as the rated voltage for the unit (rating plate) and that the
load is within the permitted power range.
•
Connect the control unit in accordance with the connection diagram.
•
Adjust set-points to zero.
•
Switch off enable (if used)
•
Check if cables are connected correctly.
The control unit is now ready for operation and can be switched on (power supply, enable).
The unit is factory set according to the rating plate i.e. 100% set point equals 100% voltage, cur-
rent or power.
Set-point control only can be used, in which case no other settings are necessary.
12.2 Measurements and Settings
Because of the phase-angle-control, the shapes of the supply voltage and current sine curves are
changed. The output voltage and current must be measured with effective value meter (true-RMS).
12.3 Putting into service without a proper load
A thyristor can only be switched ("fired") into a conducting state, if the current level is sufficiently high
enough. It will only switch-off, if the current is lower than the threshold current (every time the current
goes through the zero-crossing point). When the thyristor controller is put into service, without a proper
load, realistic measurements such as the voltage, for example, cannot be obtained. Even the setting of
the output current i.e. limit, can only be done with a proper load and not by short circuiting the output of
the thyristor controller. This is because the thyristor, once “fired”, cannot be turned off. The current has to
pass through "zero" for the thyristor to switch off. Using a low impedance load it is not possible to evalu-
ate the current level from the internal current flow.
If a proper load is not available or not possible to carry out the correct commissioning procedure then a
makeshift test can be carried by connecting a resistive load, such as incandescent lamps to the output of
the thyristor controller.
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