Matrix EPABX Vision-206S, Системное руководство

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Vision System Manual 15
Matrix
Protecting the System
The Vision does not work in isolation with the environment. It is connected to the environment in following ways.
• Power is fed to the system for functioning of the system.
• Being a PBX system, trunk lines and stations are also connected to the system.
• System also has other interfaces like External Music, PAS, DIP, Computer, Relay Port. Hence there are
chances that heavy voltages can enter the system through these interfaces.
• The system should be protected from static charges that could find their way through the system
components.
If the system is protected from these interfaces, 100% satisfactory and trouble free performance of the system
is guaranteed.
Protecting the System from heavy voltages from the mains:
The Vision is designed to work with input voltages ranging between 90 to 265VAC, 47-65Hz. The Power Supply
of Vision is designed on switch mode design and hence support such a wider range of operating voltage.
However to protect the system from abrupt changes in the input voltage, use of CVT is recommended. CVT of
100VA or 150VA is recommended.
Protecting the System from heavy voltages on the trunk lines and the overhead stations:
The Vision can get damaged if heavy voltages enter the system from trunk lines or from overhead stations.
These heavy voltages could be due to:
• Heavy voltage line falling on the CO line or on the overhead stations cable
• Thunderbolts
• Short-circuit of trunk lines or overhead station cables with electric cables
It is necessary to protect the Vision from these voltages. The protection can be in the form of some protection
devices like GDTs, MOVs, Fuses, etc. These protection devices are inbuilt for each trunk in the system.
These devices work satisfactorily only if they are properly earthed. It is recommended that Vision is provided a
separate telecom earth. A dedicated terminal marked ‘ETH’ is provided on the MDF of the system to which the
telecom earth should be connected. Telecom earth is a dedicated earth only for the PBX. The advantage of
having a dedicated earth is that there is no risk of back voltage. There are chances that if the earth is not
perfect, instead of providing protection to the system, it may damage the system.
Protecting the System from static charges:
While installing the system or servicing the system, care must be taken to provide a path to the static charges.
It is advisable for the system engineer to touch a grounded object before touching the system before
installation or maintenance.
Protecting the System from heavy voltage on the communication cable:
The Vision provides a communication port to which a computer can be connected. It is recommended to run the
cable connecting both the devices through the conduit carrying telephone cables or through a separate
conduit. By fluke if an electrical wire carrying heavy voltage shorts with this cable, heavy voltages can damage
the communication port.
Protecting the System from heavy voltage on the External music port:
The external music port of the Vision should be protected from:
• Heavy voltages on the cable connecting the Vision and the external music source due to shorting with any
electrical wire.
• An audio signal, which is not as per the specifications, is fed to this port. Please refer ‘Music On Hold’ for
specifications.