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A snow melting system can offer a safe, conve-
nient, and cost effective way of removing snow
and ice from the snow melting slab and similar
surfaces . Safety is increased by activating the
snow melting system as soon as the snow falls
rather than waiting for mechanical snow removal
after snow has accumulated . This eliminates slip
hazards and reduces the risk of injury by mecha-
nized snow melting equipment, thereby reducing
potential liability costs . The elimination of snow
plow equipment and corrosive salts also reduces
damage to the slab surface and to the environ-
ment . When controlled correctly, snow melting
systems can be cost competitive compared to
mechanical snow removal .
The Interface 681 can operate in one of four
different ways:
Snow Melting Overview
Automatic snow and ice detection requires the
installation of a Snow/Ice Sensor 090 . The sensor
is installed in-slab, level with the melting surface .
The 681 continually monitors the sensor for
the presence of moisture and slab temperature
conditions in which snow or ice may be pres-
ent . When moisture is detected, the 681 shows
“Snow Detected: True” in the Home Screen .
When the sensor is dry and the slab is up to tar-
get temperature the 681 will transition to "Snow
Detected: False" .
Snow/Ice
Sensor 090
Snow Detected: True/False Operation with the Snow/Ice
Sensor 090
Snow Detected: True
The 681 communi-
cates to the BAS to
signal snow or ice is
detected .
Snow Detected: False
The 681 communicates
to the BAS to signal snow
or ice is not detected .
CWCO
The 681 communicates
to the BAS to signal snow
or ice is not detected due
to cold temperature .
WWSD
The 681 communicates
to the BAS to signal snow
or ice is not detected due
to warm temperature .
When snow has been detected and the 681
enters a WWSD or CWCO condition, the 681 will
switch to "Snow Detected: False" .
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 681 to automatically determine the best suitable
sensitivity setting for the installation .
Sequence of Operation
