tekmar 665 Snow Detector & Melting Control Installation - Manual (Page 7)

7 of 28 © 2012 D 665 - 04/12
External Melt Demand (DIP switch set to Melt Demand)
The snow melting system is enabled when a voltage between 24 and 240 V (ac) is applied
across the Melt/Idle Demand terminals (9 and 10). An external melt demand must be
present for at least 4 seconds in order to start the snow melting system. If the RUN TIME
reaches 0:00 and the external melt demand is still present, the control continues melting
until the external melt demand is removed or the system is otherwise stopped.
Note: This operation only occurs if the Idle Demand / Melt Demand DIP switch is set to
the Melt Demand position.
AUTOMATIC MELTING ENABLE (Snow / Ice Sensor 090)
The 665 uses the Snow / Ice Sensor 090 to provide an automatic melting enable signal to
start the snow melting system. The control continually monitors the 090 for the presence
of moisture. Once moisture is detected, the water pointer is displayed in the LCD and the
snow melting system is enabled.
Water Detection Sensitivity (SENSTVTY)
The 665 has a Sensitivity setting which compensates for varying outdoor conditions which
could affect how the moisture detector in the 090 interprets the presence of moisture.
This adjustable setting is available through the SENSTVTY item in the ADJUST menu of
the control. As snow becomes contaminated with dirt, and as the sensor itself becomes
dirty, the control may incorrectly indicate the presence of water. If this condition occurs,
clean the surface of the sensor and / or turn down the SENSTVTY setting. If the snow in
your area is very clean, the SENSTVTY setting may need to be increased before snow
is detected. If AUTO is selected, the control automatically adjusts the sensitivity level
used to detect moisture.
Section C2: Snow Melting Disable
The snow melting system can be disabled manually or automatically. A melting disable signal applied to the control takes the zone
out of the melting mode. Once the snow melting system is disabled, the zone operates in the idling mode. The idling mode allows the
zone to be operated at either a lower temperature or turned off.
MANUAL MELTING DISABLE
A manual melting disable signal requires the user to manually stop the snow melting system and can be provided from the Stop
button on the control, Remote Start / Stop Module 039, Remote Display Module 040, or an external idle demand.
Stop Button on the Control
The Stop button on the control can be used to stop the snow melting system. The snow melting system is disabled by pressing
the Stop button on the control while in the VIEW menu. Once the snow melting system is disabled, the word STOP is displayed
for 5 seconds in the STATUS item of the appropriate zone while in the VIEW menu.
Remote Start / Stop Module 039
A Remote Start / Stop Module 039 can be used to stop the snow melting system. The snow melting system is disabled by press-
ing the button on the face of the 039. When the system is stopped, a solid Red Indicator Light is displayed on the face of the 039
for five seconds. If the snow melting system is disabled while there is still an external melt demand for snow melting, the 039
displays a solid red indicator light until the external demand is removed.
Remote Display Module 040
A Remote Display Module 040 can be used to stop the snow melting system. The snow melting system is disabled by pressing
the
▼ button on the 040 while in the VIEW menu. Once the snow melting system is disabled, the word STOP is displayed for 5
seconds in the STATUS item while in the VIEW menu.
9 10
Melt / Idle
Demand
24 to 240 V (ac)
N
L
Idle Demand
Melt Demand