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With the Snow Sensor 095 automatic snow/ice
detection occurs . The sensor is aerial mounted
on a pole near the melting surface .
The 681 continually monitors the sensor 095 for
the presence of moisture and slab temperature
conditions in which snow or ice may be present .
When snow or ice is detected, the 681 will show
“Snow Detected: True” on the Home screen .
When the sensor is dry, the 681 will show “Snow
Detected: False” .
The 681 will report Snow Detected: False as soon
as the 095 sensor is dry . The BAS system must use
Snow Sensor 095
Snow Detected: True/False Operation with the Snow Sensor 095
a timer to ensure all snow and ice has melted from
the slab .
The 681 includes a Sensitivity setting in the
Setpoints menu that allows the installer to adjust
the amount of moisture required to set Snow
Detected as True or False . In areas with dust
and/or air pollu-tion, the sensitivity may need
to be increased . The default sensitivity setting
is Auto . This setting allows the control to auto-
matically determine the best suit-able sensitivity
setting for the installation .
The 681 supports the BAS to control the slab
temperature which is critical to reduce the cost of
snow melting . This requires that either a Snow/
Ice Sensor 090 or a Slab Sensor 072 is installed .
The Snow/Ice Sensor contains a built-in slab
temperature sensor while the Aerial Snow Sensor
095 requires the Slab Sensor 072 . The 681
continually monitors the sensors for the slab tem-
perature conditions . This value is communicated
to the BAS through BACnet MS/TP to cycle the
heat source and the mixing device to control the
slab temperature setpoint .
Slab Sensor
Outdoor Sensor
An outdoor air temperature is mandatory for
proper operation . The 681 either has the option
to measure the outdoor temperature directly with
the Outdoor Sensor 070 or receive the informa-
tion from the BAS . These options are selected by
the Outdoor settings in the Sensor Menu .
A Slab Sensor 072 is highly recommended with
the Sensor 095 in order to measure the slab
temperature . This allows the BAS to regulate the
slab temperature and operate the snow melting
system at the highest possible efficiency .
When a Slab Sensor 072 is installed, both con-
ditions of the slab must reaching the slab target
and the Snow Sensor 095 being dry must be
met before the state changes to Snow Detected:
False .
When a Slab Sensor 072 is not installed, the
interface assumes that the slab reaches the slab
target, and the state changes to Snow Detected:
False as soon as the Snow Sensor 095 is dry .
Snow Detected: True/False Operation with the Snow
Sensor 095 and Slab Sensor 072
Snow Sensor 095
Slab Sensor 072
