Grounding Concept - Siemens SINUMERIK 840 sl Manual

Technical data
9.1 Supplementary electrical conditions
Inadequately fused supply cables can be life-threatening
In the case of supply lines > 10 m, protectors must be installed at the device input in order to
protect against lightning (surge).
The DC power supply must be connected to the ground/shield of the NC for EMC and/or
functional reasons. For EMC reasons, this connection should only be made at one point. As
a rule, the connection is provided as standard in the S7-300 I/Os. In exceptional
circumstances when this is not the case, the ground connection should be made on the
grounding rail of the NC cabinet (also refer to /EMC/EMC Installation Guide.)
Table 9-1
Rated voltage
Non-periodic overvoltages
Transient voltage interruptions
See also
Grounding concept (Page 58)
9.1.2

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
58
WARNING
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
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
Machine control panel: MCP 398C
Manual, 07/2018, A5E43199783B AB