background image

R7M-MS4

P. 6 / 7

EM-7803-Q Rev.3

 

WARNINGS AND CAUTIONS WHEN LAYING CABLES

Signal cables connected to the R7M contain high-frequency components.  Since these cables has the same effect as an an-
tenna, they emit these high-frequency components to the external space as noise or overlaps noise from the external space 
on themselves.
Cables with shielding should be used for the signal line due to the above reason.
EMC conformance test is conducted in the condition that shielded cables and earth clamps are used with the R7M.
Warning and cautions when laying cables are stated below.  These points of cautions are illustrated in the next page.

• 

Use shielded cables for those signal cables installed out of the control panel and for thermocouple and RTD extension wires.

• 

All the network cables connected to R7M should be shielded.

• 

Use shielded cables for network communication.

• 

Expose the shield at a part of the cable cover, clip it with an earth clamp, and ground it to the internal panel of the control 
panel.  A drain wire connected to the panel in a pig-tail form cannot maintain low impedance against high-frequency noise, 
thus grounding (noise shielding) in this form will not be effective.

  

Supplement

Additional measures may be taken depending upon actual installation sites.  These points of cautions are illustrated in the 
next page.

• 

Keep cables as short as possible.  It prevents noise emissions from the cables and noise overlapping to the cables.

• 

Attach a ferrite core to reduce noise impact to the signal cables susceptible to the noise.  Ferrite core can be attached close 
to the cable outlet of the control panel or close to the I/O terminal or connector, whichever is more effective.  Also, the impact 
might be reduced by winding the cable around the ferrite core for extra turns or attaching multiple ferrite cores.

• 

Keep cables which are easily affected by noise away from those which can be a noise source.

Motor Drive

Cable

Power Supply 

Cable

DC Signal Cable

Network Cable

Analog Signal

Cable

Often being a noise source

Often subject to noise interference.

In the following are examples of effective ways to lay cables separately: 

• 

Keeping physical distance (farther than 20 cm from motor drive cables, farther than 10 cm for other groups).

• 

Dividing off by a grounded metal plate

• 

Grouping into separate grounded metal pipes or cable shields.

Wires on each side of a filter should not be too close to each other.  Noise could ride onto the other side of cable.
Extra attention needs to be paid at the following parts.

• 

Noise filter that is enclosed in power cables.

• 

Ferrite core that is attached to signal cables.

• 

Noise limiting circuit (surge quenching circuit, transient absorber circuit, etc.) that is enclosed in signal cables.

056 222 38 18

[email protected]

www.sentronic.com

SENTRONIC

AG

Summary of Contents for R7M-MS4-R

Page 1: ...lightning surge protectors for those wires connect ed to remote locations Choose a surge protector with its maximum surge voltage 40V or less between lines Rec ommended M System model MDP D24 POWER IN...

Page 2: ...AUD RATE Baud Rate is selected with the rotary switch 5 4 3 2 1 0 9 8 7 6 Baud Rate Setting 0 38 4 kbps factory setting 1 19 2 kbps 2 9600 bps 3 4800 bps EXTENSION MODULE Combinations with all extensi...

Page 3: ...ETER max min EXTENSION CONNECTOR In order to improve EMC performance bond the FG terminal to ground Caution FG terminal is NOT a protective conductor terminal WIRING INSTRUCTIONS SCREW TERMINAL Torque...

Page 4: ...g R7M are stated below Use control panels with an internal panel plate both made of metal when installing the R7M Make sure to adequately ground the control panel and the internal panel plate with a t...

Page 5: ...d the panel cover with an earth strap grounding may be strengthened and EMC may be improved Ground the control panel at low impedance using e g braided wires Keep the opening for ventilation as small...

Page 6: ...ons are illustrated in the next page Keep cables as short as possible It prevents noise emissions from the cables and noise overlapping to the cables Attach a ferrite core to reduce noise impact to th...

Page 7: ...us Keep the cable as short as possible To external apparatus Shielded Cable Earth Clamp Remove a part of the shielded cable cover and ground it to the internal panel plate using an earth clamp To conn...

Reviews: