User's Manual

Site Requirements 90DIB500R41SR_FCC02 – 99.1 29
DIB-500 R4.1 Requirements concerning the operation room
Grounding and overvoltage protection
To protect the GPS antenna input against overvoltage (caused by lightning, for exam-
ple), a GPS protector is optionally available that should be used in combination with a
lightning surge protector to provide for optimum overvoltage protection. The GPS pro-
tector can be ordered separately.
GPS overvoltage concept
When using the GPS protector, the GPS supply lines at the entry into the building
should be safeguarded against high overvoltages by a grounded lightning surge protec-
tor.
Table 4.6 lists the requirements for the lightning surge protector.
It must also be ensured that all interfaces of the product are secured against transient
overvoltages. These short-term inductive, capacitive or static overvoltages of a few mil-
liseconds occur, e.g. because of adjacent interference sources, and can interfere with
voltage supply and signal feed lines.
Standards and Guidelines
For information on potential or required measures for installing safety equipment
against transient overvoltages for the V
DC
voltage supply, please refer to the standard
ETSI TR 100 283.
The required measures for installing safety equipment against transient overvoltages for
the V
AC
voltage supply are described in section 4.3.2 on page 29.
4.3.2 Overvoltage protection of the voltage supply (V
AC
)
For V
AC
voltage supply systems, ensure that the voltage source on site meets the fol-
lowing demands:
| The voltage supply circuit of the voltage source must not exceed 275 V
AC
.
| The voltage source must be connected to a grounding system. The voltage between
the grounding connector and earth must not exceed 275 V
AC
.
| Appropriate safety measures must be taken to protect the voltage supply circuit of
the voltage source against overvoltages.
| A sub-distribution system including a fuse must be available for each equipment
rack in the voltage supply circuit of the voltage source.
Table 4.6 Requirements for the lightning surge protector
Property Requirement/Value
Overvoltage discharger
Gas discharge tube
1)
1) Depending on the manufacturer, the gas discharge tubes may have to be ordered se-
parately and integrated into the overvoltage discharger.
Trigger voltage 90 V