Axcera INNOVATOR, Инструкция по эксплуатации

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UHF Analog Driver/Transmitter/ Chapter 3, Site Considerations,
Translator Installation and Setup Procedures
LX Series, Rev. 3 3-2
rarely if ever attainable in the real world.
However, the closer the environment is to
this design, the greater the operating
capacity of the transmitter.
The fans are designed and built into the
transmitter will remove the heat from
within the modules, but additional means
are required for removing this heat from
the building. To achieve this, a few issues
need to be resolved. The first step is to
determine the amount of heat to be
removed from the transmitter room.
There are generally three sources of heat
that must be considered. The first and
most obvious is the heat from the
transmitter itself. This amount can be
determined for a 100 Watt transmitter by
subtracting the average power to the
antenna (69.5 watts) from the AC input
power (675 watts) and taking this number
in watts (605.5) and then multiplying it by
3.41. This gives a result of 2,065, the
BTUs to be removed every hour. 12,000
BTUs per hour equals one ton. Therefore,
a 1/4-ton air conditioner will cool a 100W
transmitter.
The second source of heat is other
equipment in the same room. This
number is calculated in the same way as
the equation for BTUs. The third source of
heat is equally obvious but not as simple
to calculate. This is the heat coming
through the walls, roof, and windows on a
hot summer day. Unless the underside is
exposed, the floor is usually not a
problem. Determining this number is
usually best left up to a qualified HVAC
technician. There are far too many
variables to even estimate this number
without reviewing the detailed drawings of
the site that show all of the construction
details. The sum of these three sources is
the bulk of the heat that must be
removed. There may be other sources of
heat, such as personnel, and all should be
taken into account. Now that the amount
of heat that must be removed is known,
the next step is to determine how to
accomplish this. The options are air
conditioning, ventilation, or a combination
of the two. Air conditioning is always the preferred method and is the only way to
create anything close to an ideal
environment.
Ventilation will work quite well if the
ambient air temperature is below 100° F,
or about 38° C, and the humidity is kept
at a reasonable level. In addition, the air
stream must be adequately filtered to
ensure that no airborne particulates of
any kind will be carried into the
transmitter. The combination of air
conditioning for summer and ventilation
during the cooler months is acceptable
when the proper cooling cannot be
obtained through the use of ventilation
alone and using air conditioning
throughout the year is not feasible.
Caution: The use of air conditioning
and ventilation simultaneously is not
recommended. This can cause
condensation in the transmitters.
The following precautions should be
observed regarding air conditioning
systems:
1.
Air conditioners have an ARI
nominal cooling capacity rating. In
selecting an air conditioner, do not
assume that this number can be
equated to the requirements of
the site. Make certain that the
contractor uses the actual
conditions that are to be
maintained at the site in
determining the size of the air
conditioning unit. With the desired
conditioned room temperature
under 80° F, the unit must be
derated, possibly by a substantial
amount.
2.
Do not have the air conditioner
blowing directly onto the
transmitter. Under certain
conditions, condensation may
occur on, or worse in, the
transmitter.
3.
Do not separate the front of the
transmitter from the back with the