Motorola iDEN Site Controller System Manual page 41

Gen 3 Site Controller System Manual Chapter 3 Pre-Installation
Site Planning
The environmental equipment must be rated such that it is able to maintain
the environment to meet the equipment heat dissipation values, which are
given in British Thermal Units (BTUs)/per hour.
BTU/h can be figured by multiplying the power rating of the equipment by a
factor of 3.414. For example; a Cabinet with a standby Controller produces
160 Watts, which is equivalent to 546 BTU/h (160 x 3.414 = 546 BTU/h).
The site control equipment operates on a -48 Vdc power system including
batteries. Should AC power be lost, the DC power system continues to
supply the site control equipment with the necessary power. Because the site
control remains operational during loss of AC power, heat is still generated
by the equipment. Unless the site HVAC is on a backup system, the
generated heat will affect the operation of the equipment. The operation of
the site control equipment degrades when temperatures exceed 140˚ F (60˚
C).
For sites containing more than one-hour battery backup, the effect of
generated heat should be considered. The HVAC system design should be
evaluated to insure the proper operating environment is maintained during
loss of AC power.
Redundant HVAC Systems
A redundant HVAC system may be installed, if necessary. It must be wired
on a delayed circuit to prevent both HVAC systems from starting up
simultaneously. The HVAC system should be capable of automatically
switching between the heating and cooling modes in response to the
thermostat. The controls must ensure that both modes never operate
simultaneously.
Existing HVAC Systems
Existing building HVAC systems may be programmed to turn off during
non-occupied hours. This type of HVAC system must be evaluated to insure
that the site temperature is maintained.
Humidity Control and Air Cleanliness
The relative humidity within the site should be less than 95%
non-condensing, non-operating; 90% non-condensing while operating. The
site should also be a relatively dust-free environment. Take proper measures
to ensure the cleanliness of the site and that it remains a relatively
dust-free environment.
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68P80801E30-A 5/1/2002