Siemens SIMATIC S7-300 Module data Hardware And Installation Manual

Appendix
S7-300 Programmable Controller Hardware and Installation
11-6 A5E00105492-01
11.2.2 Five basic rules for insuring EMC
If you conform with theses five basic rules ...
you can insure EMC in many cases!
Rule 1: Large-area grounding
When you install the automation equipment, make sure that surfaces of inactive
metal parts are well bonded to chassis ground (see the following sections).
• Bond all passive metal parts to chassis ground, ensuring large area and low-
impedance contact.
• When using screw connections on varnished or anodized metal parts, support
contact with special contact washers or remove the protective insulating finish
on the points of contact.
• Wherever possible, avoid the use of aluminum parts for ground bonding.
Aluminum is highly corrosive and is therefore less suitable for ground bonding.
• Create a central connection between chassis ground and the equipotential
busbar/protective conductor system.
Rule 2: Proper cable routing
Ensure proper cable routing when you wire your system (see the section below on
Indoor/outdoor cable routing).
• Sort your wiring system into groups (high-voltage/power supply/signal/data
cables).
• Always route high-voltage, signal or data cables through separated ducts or in
separate bundles.
• Install the signal and data cables as close as possible to grounded surfaces
(e.g. supporting beans, metal rails, steel cabinet walls ).
Rule 3: Mounting the cable shielding
Take care that all cable shielding is properly fastened (refer to the section on
Shielding of cables).
• Always use shielded data cable. Always connect both ends of the shielding to
ground on a large area.
• Analog cables must always be shielded. For the transmission of low-amplitude
signals it might prove to be more efficient to have only one side of the shielding
connected to ground.
• Directly behind the cable entry in the cabinet or enclosure, terminate the
shielding on a large area of the shielding/protective ground busbar and fasten it
with the help of a cable clamp. Then, route the cable to the module; however,
do not connect the shielding once again to ground in this place.
• Connections between the shielding/protective ground busbar and the
cabinet/enclosure must be of a low impedance.
• Always install shielded data cables in metal/metallized connector housings.

Siemens SIMATIC S7-300 Module data Specifications

General

Series	S7-300
Manufacturer	Siemens
Protection Class	IP20
System	SIMATIC S7-300
Digital Inputs	Varies by module
Digital Outputs	Varies by module
Analog Inputs	Varies by module
Analog Outputs	Varies by module
Central Processing Unit	Varies by CPU model
Supply Voltage	24V DC or 120/230V AC
CPU Type	Varies (e.g., CPU 312, CPU 315, etc.)
Memory	Varies by CPU model
Communication Interfaces	MPI, PROFIBUS
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Operating Temperature	0°C to 60°C
Storage Temperature	-40°C to 70°C
Relative Humidity	10% to 95% (non-condensing)