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Grounding and protective earth
The Outdoor Unit (ODU) must be properly grounded to protect against lightning. It is the user’s
responsibility to install the equipment in accordance with national regulations. In the USA follow the
requirements of the National Electrical code NFPA 70-2005 and 780-2004
Installation of Lightning
Protection Systems
. In Canada, follow Section 54 of the
Canadian Electrical Code
. These codes describe
correct installation procedures for grounding the outdoor unit, mast, lead-in wire and discharge unit, size
of grounding conductors and connection requirements for grounding electrodes. Other regulations may
apply in different countries and therefore it is recommended that installation of the outdoor unit be
contracted to a professional installer.
DC supply
To power the ODU from a DC supply, use the AC+DC enhanced power injector (PSU) (Cambium part
number C000065L002C). Ensure that the DC power supply meets the requirements specified in the
PTP 670
Series User Guide
.
Powering down before servicing
Before servicing PTP 670 equipment, always switch off the power supply and unplug it from the PSU.
Do not disconnect the RJ45 drop cable connectors from the ODU while the PSU is connected to the power
supply. Always remove the AC or DC input power from the PSU.
Primary disconnect device
The main power supply is the primary disconnect device. The AC-DC enhanced power injector is fused on
the DC input. Some installations will also require an additional circuit breaker or isolation switch to be
fitted in the DC supply.
External cables
Safety may be compromised if outdoor rated cables are not used for connections that will be exposed to
the outdoor environment. For outdoor copper Cat5e Ethernet interfaces, always use Cat5e cable that is gel-
filled and shielded with copper-plated steel. Alternative types of drop cable are not supported by Cambium
Networks for use with PTP 670.
Drop cable tester
A drop cable tester must NEVER be used at the ODU end connected to the power supply from the PSU. It
must only be used at the bottom of the mast with a multimeter. This is because the PSU voltage exceeds
the limit allowed in some countries for safe handling in wet conditions and therefore may create a safety
hazard.
RF exposure near the antenna
Strong radio frequency (RF) fields will be present close to the antenna when the transmitter is on. Always
turn off the power to the ODU before undertaking maintenance activities in front of the antenna.
Minimum separation distances
Ensure that personnel are not exposed to unsafe levels of RF energy. The units start to radiate RF energy
as soon as they are powered up. Never work in front of the antenna when the ODU is powered. Install the
ODUs so as to provide and maintain the minimum separation distances from all persons. For minimum
separation distances, see the
PTP 670 Series User Guide
.
Grounding and lightning protection requirements
Ensure that the installation meets the requirements defined in the
PTP 670 Series User Guide
.
