DS Series Snow/Rain Sensors & Controllers
Overview of the DS Series

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 spec'ed for -40oC to +85oC 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, take a look at 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. Why replace the whole controller when an inexpensive precipitation sensor may restore your system to "like new" performance?

Tired of stocking 10 different part numbers for the same basic sensor? At ASE, we exploit our microcontroller design to the fullest. Every line voltage DS unit can accept and control any input supply from 100VAC to 277VAC. And low voltage companions for the DS-2C (DS-224C) and DS-8C (DS-824C) are available for hydronic and other low voltage systems. All options and adjustments for each unit are field selectable. This allows covering all of your requirements while keeping your stock low and lead times short. Pigtail cable color codes conform to international standards and all units now ship with a 3/4" base conduit hub and a 3/4"-to-1/2" threaded reducing bushings. One sensor = one part number. Standardization means fewer variants, lower costs, and less inventory requirements for you.

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.

These signals are then supplied 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 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.

Common Features List:

Reliable Rain and/or Snow Detection
Can Also Function as a High Power Intelligent Thermostat
Line Voltage Units:
        Supply - Universal 100-277V AC 50/60 Hz Operation, No Strapping Required
        Control - Full 30A @ 277V AC, 20A @ 28V DC
Low Voltage Units:
        Supply - 22-28V AC/DC, 15VA Max
        Control - Full 30A @ 24V AC, 20A @ 28V DC
Inexpensive, Replaceable Precipitation Sensor
Easy Installation, Full Access to Electronics
10 Different Functions, 1 Part Number, Simplified Ordering
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 Min or 2-6 Hr Ranges
Adjustable Precipitation Sensitivity
Super Bright Power/Activation LED Indicator
Simple Remote Control/Monitor Capability
Selectable Low Temperature Cutoff With Unique "Recover" Mode
External Manual On-Automatic-Standby Override Switch (Except DS-4C/DS-7C)
Smart "Manual On" Operates for One Delay Off Cycle
Remote Control/Monitor Devices Are Available (See Accessories)

MODEL  DS-2C  DS-224C  DS-8C  DS-824C  DS-5C  DS-9C  DS-4C  DS-7C 
  • DS-2CDS-2C
  • DS-224CDS-224C
  • DS-8CDS-8C
  • DS-824CDS-824C
  • DS-5CDS-5C
  • DS-9CDS-9C
  • DS-4CDS-4C
  • DS-7CDS-7C
Precipitation Sensor Integral  Integral  Remote (10' Cable) Remote (10' Cable) Integral   Remote (10' Cable) Integral   Remote (10' Cable)
Input Power 100-277V AC  22-28V AC/DC  100-277V AC  22-28V AC/DC  100-277V AC  100-277V AC  100-277V AC  100-277V AC 
Control: AC 1 x 30A @ 277V AC  1 x 30A @ 24V AC  1 x 30A @ 277V AC  1 x 30A @ 24V AC  2 x 30A @ 277V AC  2 x 30A @ 277V AC   2 x 30A @ 277V AC   2 x 30A @ 277V AC  
Control: DC 1 x 20A @ 28V DC  1 x 20A @ 28V DC   1 x 20A @ 28V DC   1 x 20A @ 28V DC   2 x 20A @ 28V DC   2 x 20A @ 28V DC    2 x 20A @ 28V DC    2 x 20A @ 28V DC   
O&M Manual                
Preferred For: Lowest Cost Low Voltage Remote Sensor Low Voltage High Capacity High Capacity Antenna Optimized Antenna Optimized 
 Pavement Snowmelt                
Hydronic Snowmelt                
Roof & Gutter Deice                
Rail Switch Deice                
Sat Antenna Deice                
Sat Antenna Rain Div                
Sat Deice & Rain Div                
VSAT Deice                
Tower Deice                
Observatory Shutter                
Low Voltage Control                
Building Automation            
Skylight Control                    
Irrigation Sensing        
Operating Modes:             * *
Snow Sensor    
Snow Controller    
Rain Sensor    
Rain Controller    
Precipitation Sensor    
Precipitation Controller    
Low Temp Thermostat    

* Reference installation manual for DS-4C/DS-7C unique operating modes

Looking for Remote Control & Monitoring, Cabling, and Other Components?
Take a Look at DS Series Accessories

Inexpensive, Off-The-Shelf Ground Fault Protection Meets NEC and CEC Requirements
Consider the GF Ground Fault Protection Unit


For More Information, Contact
Automated Systems Engineering, Inc.
2833 N El Paso Street
Colorado Springs, Colorado, USA 80907
Phone: 719-599-7477

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Last Update: 06/13/22