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201401/IvxIM_v2.2
JBL Intellivox Installation Manual
Fan Control
An external cooling fan should be installed if the ambient
temperature is expected to exceed 40 °C and/or the
Intellivox will be exposed to direct sunlight. For outdoor
applications JBL offers an off-the-shelf solution (see
weather-proofing kit in the appendix). Dedicated forced
cooling solutions however can be constructed by means
of the information provided in this section.
An internal temperature-controlled output is available at
two pins of the connector; these pins should be wired to an
external 24 V DC fan as indicated in fig 10.2. One of the
pins is connected to an internal positive supply rail (FAN+,
approximately 24 V), the other one (FAN-) is driven by an
internal transistor. Note that external protection diodes are
normally not required, the FAN- signal is diode-clamped
both to the internal positive supply rail as well as to the
internal GND.
The fan should be a 24 V DC type consuming less than 3 W.
Applicable fan types are:
EBM-Papst 8314.
EBM-Papst 8414.
Sunon KDE2408.
Please note that the FAN- signal is a PWM
(Pulse Width Modulated) signal. This control
results in a temperature dependent fan speed.
It implies that this signal cannot be used to directly drive
an external relay (e.g. to control a mains-voltage fan).
Contact JBL for details with respect to the interfacing to
mains-voltage fans.
Ensure that the airflow of the fan enhances
the natural airflow (caused by convection).
Note that the supply available at the fan
control connector has a maximum current
rating of 125 mA. Fans or any other loads
consuming more than 3 W should not be connected. This
might result in the activation of an internal protection*.
*For Intellivox devices with early serial numbers this
protection is non-resetable. Please contact the service
department for more information.
