Grounding Concept - Siemens SINUMERIK 840DE sl Manual

Table 7-1
Rated voltage
Non-periodic overvoltages
Transient voltage interruptions
7.1.2

Grounding concept

Components
The SINUMERIK 840D sl system consists of a number of individual components which have
been designed so that the system complies with the appropriate EMC and safety standards.
The individual system components are:
● Numerical Control Unit (NCU)
● Machine Control Panel (MCP), Machine Pushbutton Panel (MPP)
● Keyboard
● Operator panels (operator panel front + TCU/PCU)
● Distributor box and handheld unit
● S7-300 I/O with IM 153 interface module
Grounding measures
The individual modules are attached to a metal cabinet panel. Insulating paints on the mounting
points (e.g. tension jacks) must be removed.
It is permissible to cluster the operator control components regarding connection/potential
bonding.
Example: The control panel on the swivel arm.
It is sufficient in this instance to connect the ground connections of, for example, the PCU, TCU,
and operator panel front using a cable and to route a shared grounding conductor to the central
ground connection in the control cabinet.
Please note that interruption of the grounding during maintenance work is not permissible.
Note
Proper grounding of the device and the machine corresponding to the EMC Design Guidelines
is absolutely necessary for the function of the touch screen.
Operator panel front: OP 015 black
Manual, 05/2019, A5E35227814B AB
Requirements of the DC power supply
According to EN 61131-2
Voltage range (mean value)
Voltage ripple, peak/peak
Ramp-up time when switched on
Period of overvoltage
Recover time
Events per hour
Downtime
Recovery time
Events per hour
Technical data
7.1 Secondary electrical conditions
24 VDC
20.4 VDC to 28.8 VDC
5% (unsmoothed 6-pulse recti‐
fication)
any
≤ 35 V
≤ 500 ms
≥ 50 s
≤ 10
≤ 3 ms
≥ 10 s
≤ 10
79