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I) Overview
The PM Series Power Module is a uniquely adaptable communication
equipment power source which functions as either power supply or battery
charger for 12, 24 or 48 volt d.c. systems positive, negative or floating
ground. Power Modules may be employed singly or in combina tion,
enabling the installer to scale the system output from 560 to 6,000 watts
per rack. Units may be paral leled for N + 1 redundancy and alarm contacts
allow local or remote mon itoring. An optional d.c. wiring quick connect kit
allows easy replacement of modules while the system as a whole remains
up and running (see section V-B).
Power Modules may be used separately as a power source, or they may
be integrated with NEWMAR's Power Function Manager (model PFM-400;
rated to 400 amps maximum) to greatly expand the system capability with
other functions such as digital output monitoring, multiple load distribution
and low voltage disconnect. (Contact the factory for complete information
regarding the PFM-400.) Note: If the Power Module is being installed
as part of an integrated system with the PFM-400 refer to the manual
which comes with that unit for all d.c. wiring instructions and functional
descriptions.
II) AC Power Quality and EMI Compatibility
A) AC Power Quality
Reliability is of prime concern when designing an AC-DC power
system for communication sites. Poor AC input power quality
can seriously impede system reliability. In particular, transient
disturbances on the power lines can severely weaken or cause
failure of semi-conductors in power supplies and communication
gear. It is important that you know the input power quality when
installing the PM. Following is some basic information on the
subject:
Causes
Transients are characterized as a voltage pulse of high energy and very
short duration impressed upon the AC wave form. These over voltage
pulses can range from 1 to 100 times the normal AC voltage level and can
last for a fraction of a cycle to a few cycles.
Transient disturbances can be placed into two categories:
- Lightning generated
- Equipment generated
A direct lightning hit on a utility power line will cause a high energy voltage
transient to travel in both directions along the power line. This disturbance
can affect equipment hundreds of miles from the strike point.
Equipment generated transient sources include utility fault conditions
and load switching as well as on-site equipment such as pumps and air
conditioning loads, motors, phase control equipment.
Recommendations
All PM models are designed to meet IEEE 587/ANSI C62.41 requirements
for transient withstand capability. The AC power source should conform to
this specification to ensure reliable power supply operation.
If the power source quality is suspect or unknown, it is recommended that
an AC power quality survey be conducted by a power quality consultant
or power conditioning firm. Corrective measures may include lightning
suppressors, line conditioners and filters.
3
P.O. Box 1306, Newport Beach, California 92663 • Phone: 714-751-0488 • Fax: 714-957-1621 • E-Mail: techservice@newmarpower.com
An optional AC transient suppressor (see OPTIONS section) is
recommended for installations in third world countries and sites that are
subject to nearby lightning strikes or transients caused by nearby motor
contactors, air conditioning compressors, etc.
B) EMI (Electro-Magnetic Interference) Considerations
The PM Series Power Modules employ switch-mode technology to con-
vert AC to DC. They are designed to produce minimal EMI levels when
operating (compliant to International Standards EN55022 [conducted]
and EN50082 [immunity]). Although the level of EMI produced may be
acceptable for most radio applications, some installations may not even
tolerate what little EMI is
produced.
Analog microwave and other extremely sensitive radio sites may
require additional input/output filtering and careful installation. In some
cases linear power supplies (also available from NEWMAR) should be
considered, as they emit lower EMI (although they are more susceptible to
"brown-outs" or voltage sags and high input voltage).
C) Other Factors
Some of the various factors which must be considered when discussing
electrical interference include the following:
- RF Signal strength
- Ground loops
- Power and signal cable routing proximity
- Power supply and radio mounting locations
- Antenna, signal, and power grounds
III) Installation
Two notes regarding nomenclature used in this manual
1) For the sake of brevity the PM Series Power Module is referred to
simply as the PM (meaning all models, generically).
2) Where installation differences exist, reference is made to 560 watt or
1,000 watt models.
560 watt models refers to:
PM-12-40
PM-24-20
PM-48-10
1,000 watt models refers to:
PM-12-70
PM-24-35
PM-48-18
PM-12-45
Note: This section covers only mounting, input and output wiring. Two
installation options, Remote Shutdown wiring and Local/Remote Alarm
wiring, are covered in those sections in the OPERATION portion of this
manual.
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