Gasboy CFN Series Site Controller III - Manual (Page 37)

MDE-4298D CFN Series Site Controller III Installation Manual · September 2009 Page 33
Communication Requirements System Components Wiring
Communication Requirements
The CFN System utilizes RS-485, RS-232, RS-422, and Two-wire Current Loop modes of
communication for communicating to other CFN system components and peripheral
equipment. Phone line (modem) communication may also be used when remote
communication to the site is preferred. The specific requirements for each of these modes of
communication are listed below.
RS-485
RS-485 wiring is used for communication between the CFN system components. This
communication takes place over RS-485 modular cables provided with system components
and the RS-485 data loop field wiring. The following installation requirements must be
followed when installing CFN RS-485 communication lines:
• All wiring must be installed and used in accordance with all building/fire codes, all
Federal, State, and Local codes, National Electrical Code (NFPA 70), NFPA 30, and
Automotive and Marine Service Station (NFPA 30A) codes and regulations. Canadian
users must comply with the Canadian Electrical Code also.
• Cable: A twisted-pair shielded cable is highly recommended for RS-485 wiring. Although
it is recommended that wires be run in a conduit away from AC wires, they can be
combined in the same conduit with AC wires if a UL-listed cable with the following
specifications is used.
Conductor 18 AWG stranded wire; 2 twisted-pairs
Shield Foil-wrapped 100% coverage and/or tinned copper braid 90% coverage
Drain Wire Stranded, tinned copper, 20 AWG or larger/or braided shield
Voltage Rating Maximum operating voltage of 600 V
Environmental Gas and oil-resistant; suitable for wet or dry locations
Gasboy can supply Belden ® 1063A (Part Number C09655), which is a UL-listed,
4-conductor cable that meets the requirements listed above.
Note: Belden 1063A is UL-listed but not CSA-listed.
When a cable with a voltage rating of less than 600 V is used, it must be installed in a
conduit separate from all AC wires.
• Conduit: When you use the recommended shielded, twisted-pair cable described above,
the cable can be run with AC wires in a metal conduit. The shield drain wire must be
connected to the system AC ground. Only AC wires for the system and pumps can be
installed in the AC conduit. Do not run the cable outdoors without the use of a metal
conduit. Do not run this cable overhead when outdoors.
The cable can be run indoors without the use of a metal conduit. The shield drain wire
must be connected to the system AC ground.
If you are using a cable other than the one recommended above, the RS-485 field wires
must be installed in a metal conduit away from any AC wires.
• Distance: The following distances must be adhered to when installing the RS-485 field
wiring:
- Wiring over 100 feet must follow the specifications outlined above.
- The distance from the RS-485 junction box to the farthest CFN component is limited to
1000 feet.
- The total length of the RS-485 field wiring to all the CFN components cannot exceed
1500 feet.