Secondary Electrical Conditions; Power Supply - Siemens SINUMERIK 840D sl Manual

Technical specifications

7.2 Secondary electrical conditions

7.2 Secondary electrical conditions
7.2.1

Power supply

Requirements for DC power supplies
Electric shock due to connection of an unsuitable power supply
When equipment is connected to an unsuitable power supply and/or insufficiently grounded or
rear cover (Page 19), exposed components may carry a hazardous voltage that might result
in serious injury or death.
● Only use power supplies that provide SELV (Safety Extra Low Voltage) or PELV
Inadequately fused supply cables can be life-threatening
In the case of supply lines >30 m, protectors must be installed at the device input 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 7-1
Rated voltage
Non-periodic overvoltages
Transient voltage interruptions
78
WARNING
(Protective Extra Low Voltage) output voltages acc. to UL 61010 for all connections and
terminals of the electronics modules.
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
Operator panel front: OP 012
Manual, 05/2019, A5E36371591B AB