Theory Of Operation; Installation Instructions - ETI Snow Owl Operation Manual

any contactor that is connected to it. For this
reason care should be taken to ensure that
heater power is either connected properly or
that it is turned off/ disconnected before
powering up the sensor.
Following installation and prior to beginning
system operation refer to and perform the
post-installation tests
manual.

THEORY OF OPERATION

The SNOW OWL sensor monitors atmospheric
conditions to determine when a snow/ freezing
rain event occurs and responds by providing
a grounded output to the control circuit or
contactor which in turn will enable the heating
system.
It does this by using the snowflake shaped
moisture sensor on the top cap to melt the
snow/ ice that lands on it and then detects the
resulting water using a low voltage current.
The detection of water alone will not provide
an output but is used in combination with a
temperature reading below 38 F. An Internal
processor looks for this combination or
moisture and temperature and triggers the
output only when both conditions are present.
This allows the SNOW OWL to trigger a heat
cycle only when it is needed. Once the SNOW
OWL has triggered it will remain on until
one or both of the stimuli is removed, and it
determines that the stimuli remains missing
for the next 4 minutes.
described in this

INSTALLATION INSTRUCTIONS

With user supplied hardware, mount the
SNOW OWL securely in an upright position
(sensor snowflake at top) in a clear and open
area typical of the area to be melted, either
above the roof line or removed from the
building in an area exposed to falling snow.
• Avoid overhead trees, shrubs, wires, eaves,
etc., and falling or blowing debris.
Avoid vehicle and foot traffic. Avoid creating
•
a tripping or safety hazard.
Avoid exposure to artificial heat sources and
•
excessive shock and vibration.
Position the sensor at a height to reduce,
•
eliminate or discourage damage caused by
animals or vandals.
Install in accordance with the requirements of
all applicable electrical and building codes
and regulations. Ensure that all conduit and
cable terminations are watertight.
NEC Article 426.28 requires equipment
ground fault protection (GFEP) for ice and
snow melting equipment. This functionality is
not provided as part of this sensor and must
be provided as part of the overall system.
The SNOW OWL can be mounted at a distance
up to 500 feet away from the controller or
contactor using 22-gauge wires and up to
1000 feet using 18 gauge wires.
3 INSTALLATION GUIDE & OPERATION MANUAL | PART NO. 25484 REV B