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Posted By Topic: C Bus Cabling

Dec 01 2018 20:55

Can we run the pink CBus cabling in same conduit as power for an ethernet signal and RS485. This Cat5 cable has a mains rating

Dec 02 2018 09:24

from the C-bus manual"publisdhed bu Clipsal

"It is good practice to keep them
as far apart as possible and cross at 90 degrees to give the greatest margin of noise immunity both within the confines of the switchboard and around the installation."

Dec 02 2018 16:18

So nothing unsafe just the possible operational problems it may encounter

Dec 02 2018 16:20

And possible warranty issues if something goes awry.

Schneider may need to do a pre-line inspection of the pink Cat 5 cables before lining.

Dec 03 2018 08:08

> Can we run the pink CBus cabling in same conduit as power for an
> ethernet signal and RS485

Both Ethernet and RS485 are balanced signals with excellent common mode rejection, so there will not be any interference problems from mains wiring.

As you note, C-Bus pink is insulation rated for this use, but many common Cat5 style cables have 300V insulation ratings allowing them to be run with mains cables.

Dec 05 2018 10:43

The "product overview" says:"Suitable for use Inside Electrical Enclosures". But there's no voltage rating given.

Googling brings 2 related questions:
Q1 What is the voltage rating on the Pink C-Bus cable?
A1 The C-Bus Cat5 cable working voltage has been tested, it's rated up to and including 0.6/1 kV.

Which appears to support the claim that it can be used "inside electrical enclosures"; but

Q2 Is the pink, C-Bus cable rated at 240 volts?
A2 Yes, The Pink outer sheath of the 5005C305B Cable is rated for 240 volts.
However the internal conductors are not rated for 240 Volts .

So in reality you can run it through either a wiring enclosure or an equipment enclosure that also has LV wiring / fittings; but you can't terminate it in either.

This info is specific to the Schneider product; but I doubt most other brands are any different in this regard.

Dec 05 2018 12:41

Alec notes:

> So in reality you can run it through either a wiring enclosure or an equipment enclosure
> that also has LV wiring / fittings; but you can't terminate it in either.

The issue is that the inner, signal carrying conductors are not adequately voltage rated, but in the common use of C-bus cable, the pink is terminated into a RJ45 plug, and, with the caveat that it is done properly, the signal conductors are never exposed, there is always insulation over the inner conductors, be it the pink sheath or the plastic body of the RJ45 plug.


Dec 06 2018 10:31

D Buckely I had a shop around but couldn't find any other data cable brands that would suffice
Do you have any brand name/suppliers I could look at... I course there is the industrial ethernet products but all heavy duty and not suited to residential

Dec 06 2018 12:38

Most Belden solid cat5 seems to be rated 300V, so finding a stockist of that should do. Belden have the data sheets for their cables on their website.

I could also suggest you give Danamix a call, they are Kiwi and do lots of data cabling

They don't quote a sheath voltage in their spec sheets, but that doesn't mean it doesn't have a rating they'll provide on request.


Dec 06 2018 21:22

©2008 Schneider Electric. All Rights Reserved.
These guidelines are consistent with Best Practices and provide the best immunity
to noise.
• Follow national and local electrical codes. Refer to the product’s installation
bulletin for product-specific information on wiring, wire gauge, and so on.
• In panels and enclosures, securely anchor and sleeve C-Bus network cable and
anchor electrical power lines. This helps prevent contact between loose electrical
power conductors and the C-Bus network wiring.
• Wherever possible, consolidate multiple C-Bus network Cat-5 cables outside a
panel or enclosure so that only one C-Bus cable is brought into the enclosure.
• Insulate any consolidation of multiple C-Bus network cables in panels or
enclosures so that there are no loose wires, no exposed terminal screws, etc.
• If C-Bus network cable is run in parallel with electrical power lines (outside an
enclosure), there must be at least 6 in. (152 mm) segregation between the two
cables at all times.
• If C-Bus network cable will cross an electrical power line, the crossing must be
at a 90° angle. Also provide at least 2.5 in. (64 mm) separation between the two
cables where they cross.
• Limit the current on a C-Bus network to 2 A or less.
• Limit the total length of Cat-5 cable on a single network to 3281 ft (1 km).
• To control a light from two, four, or more switch locations, give the same Group
Address to one or more buttons on each switch and the Relay or Dimmer.
• To control multiple Relay or Dimmer channels from a single switch, give the
various Relay and/or Dimmer channels the same Group Address as the switch.
For a description of the status indicators’ activity on other types of units, such as an
input unit, see the other side of this guide or the unit’s installation bulletin.
NOTE: The Unit and C-Bus indicators on output units only function when output
units are connected to 120/277 V AC.
Indicates the status of the individual unit and whether it is receiving line-level
• ON (lit): the unit is receiving line-level voltage.
• Flashing: the Local or Remote Overrides have been toggled ON or OFF.
• OFF (unlit): there is no line-level voltage.
Indicates the status of the C-Bus network at the unit:
• ON (lit): there is a C-Bus Clock and an acceptable level of C-Bus network power
(recommended range is 22–36 V DC).
• Flashing: the line voltage on the C-Bus network is marginal (15–20 V DC).
• OFF (unlit): no C-Bus System Clock or no C-Bus network power.

Dec 07 2018 07:47

Question initially is not about a CBus installation. Different application.

Dec 07 2018 10:17

Phazor, yes it does.