Features of the ASE DS-4C Rain/Snow Sensor Control

The ASE DS series of sensors and controllers provide a balance between price, sophistication, and control capabilities and capacities. Each unit is housed in a sturdy NEMA 3R enclosure rated for outdoor use. All internal electronic components are specified for -40degC to +85degC operation. All line voltage units are ETL UL Standard 508/CSA C22.2 No. 14 Listed and European CE EMC directives have been achieved, opening the door for both domestic and overseas use. If you are tired of throwing old sensors away with no possibility of repair, consider using the DS series. Unlike "potted" sensors and controllers, every DS unit offers full access to the sensor electronics. This unique design allows configuring and adjusting the unit for most efficient operation. The precipitation sensor may also be replaced in the field.

• Reliable Rain and/or Snow Detection.
• NEMA 3R Enclosure Rated for Outdoor Use.
• All Line Voltage Units Are ETL UL Standard 508/CSA C22.2 No. 14 Listed.
• Input Power - Universal 100-277 VAC, 50/60 Hz Operation.
• Dual Control Relay - Full 30A @ 277 VAC, 20A @ 28 VDC.
• Integral Precipitation Sensor.
• Easy Installation, Full Access to Electronics.
• Standard 3/4" NPT Conduit Hub, Includes 3/4" to 1/2" Reducer.
• Adjustable Temperature Trigger Point.
• Adjustable Delay Off Drying Timer with 30-90 Minute or 2-6 Hour Ranges.
• Adjustable Precipitation Sensitivity.
• Super Bright Power/Activation LED Indicator.
• Simple Remote Control/Monitor Capability.
• Selectable Low Temperature Cutoff with Unique "Recover" Mode.
• Smart "Manual On" Operates for One Delay Off Cycle .
• Remote Control/Monitor Devices Are Available (See Accessories) .

Basic Theory of Operation.

All DS units operate by detecting environmental conditions through a base mounted temperature sensor and a heated precipitation sensor. When rain or snow land on the precipitation sensor the traces are bridged, and a closure is detected. The heater then rapidly evaporates the moisture, clearing the sensor. The sensor for the DS-2C, DS-224C, DS-4C, and DS-5C simply screws into the top of the controller enclosure. The DS-7C, DS-8C, DS-9C, and DS-824C precipitation sensors are connected to a 10-foot cable and are intended for remote mounting, either on a feed boom for satellite antenna deicing or in a gutter or downspout for roof deicing.

The signals from the sensors are then directed to the microcontroller. Depending on the way the user has configured the sensor, the microcontroller determines the appropriate action to perform. For example, the DS-4C contains two control relays. Using the profile selection switch (see the DS-4C page for more information) the controller can close one relay for low temperature detection and the other for precipitation detection. It can also be configured to close one relay when rain is detected and the other when snow is detected. It can also close both relays only when snow is detected, allowing control of larger loads.

The difference between "sensor" and "controller" modes is the "Delay Off" drying cycle provided by each configuration. "Delay Off" time is the amount of time the sensor/controller will hold the load control relay(s) closed after the last detection of rain or snow. Proper setting of "Delay Off" assures that pavement or roofs not only melt but are also dry, reducing the chance for dangerous refreezing of water left behind. A sensor is used to activate an external control unit when rain or snow is occurring. The external control unit activates and operates the deicing system as required. A controller is expected to not only detect snow or rain conditions but to also directly control the attached equipment. A DS series unit set as a controller provides a longer delay off time, typically 30-90 minutes or 2-6 hours, allowing the heating system to dry the surface and prevent refreezing.

All DS units provide a remote "control/monitor" interface, a point where ASE or customer supplied devices can be connected to remotely monitor activation of the system and/or manually activate or disable the controller. Some units also feature a built-in switch to perform these same control functions directly from the sensor. The rack-mounted DP-7B or wall-mounted CDP-2 Remote Control/Status Panels may be directly connected to any DS series sensor/controller in order to provide both remote control and monitoring of DS sensor/controller operation.