Specifications

Masterclock, Inc.
phone (USA and Canada): 1-800-940-2248 | phone (international): [phone]
email: [e-mail] | online: www.masterclock.com
SURGE ARRESTOR INSTALLATION
WARNING
Ensure that the antenna and coaxial cable that the surge arrestor is protecting is not exposed to direct lightning
strikes. This device offers no protection for such strikes and will be destroyed – along with whatever equipment
that it is connected to - by a direct strike.
Notice:
The installation, maintenance, or removal of antenna and surge arrestor systems requires qualified, experienced
personnel. These installation recommendations are written for such personnel. Installations of this type of
energy suppression equipment should be made in accordance with local safety and electrical codes and with
regard to good electrical and engineering practices. If you have questions regarding the use of this type of
product with respect to your installation, contact a local licensed electrical contractor for the latest electrical
codes and guidelines. In no event shall Masterclock, Inc. be liable for any direct, indirect, special, incidental, or
consequential damages caused from the installation or use of this product.
Installation:
For maximum protection install two surge arrestors, one outside, either close to the antenna or at the point where
the coaxial cable enters the building and a second as close to the receiving equipment. A good rule of thumb to
remember is that all lines entering or exiting a building need protection.
The SA90 is a bidirectional RF device. Either RF port may be connected to the equipment side or the antenna side
of the transmission line interface to provide protection. Do not leave the RF ports exposed when installed
outdoors.
The surge arrestor must be grounded by attaching a ground wire to the grounding lug. This wire must be attached
to a master ground bar or the systems earth grounding to ensure a low impedance path to ground. During
installation, all grounding contact surfaces must be clean, dry, and free of oxidation.
Grounding Recommendations:
A protection system with a poor ground is the same as having no protection at all.
Recommended grounds are the utility company ground, a ground rod, well casings, and cold water pipes that are
of continuous metal. A note of caution, sometimes the metal-cold water pipes are repaired and/or extended PVC
piping. The introduction of PVC material renders the cold water pipe ground unacceptable. A thorough
investigation of a cold water pipe ground is important since the PVC repairs or extensions may be covered by
drywall. Grounds that are unacceptable include sprinkler pipes, PVC pipe, conduit, buried wire and any ground
that cannot be verified.
Bonding ensures the most effective ground. Bonding ties all of the grounds in the building together electrically. If
there is a rise in ground potential and all of the grounds are bonded, no damage will occur since it is differential
voltage that causes problems.
It is absolutely necessary to make sure that the ground used for the AC power is the same as the ground used for
the data-line surge protectors. A common ground reference must be achieved for all equipment.
All ground wires must be as short as possible and it is imperative
that the ground wire not be coiled nor looped –
it must be as straight as possible. Regarding the diameter of the ground wire, the larger the better.
Finally, the earth ground resistance on which the whole grounding system relies, must be less than 5 ohms
between any two points within the ground system.
GPS Instruments
SA90
10.2