Snow switch PD Pro

Snow and Ice Melting Systems Control: Automatic, Pilot Duty Applications

Utilizing standard Environmental Technology snow and ice sensors (sold separately), the automatic Snow Switch® Model PD Pro control is used in snow and ice detection and melting for pavement, sidewalks, loading docks, roofs, gutters and downspouts in commercial and residential environments. The PD Pro interfaces with up to two standard Environmental Technology sensors to meet site requirements. The CIT–1, GIT–1, and SIT–6E sensors reliably detect snow and ice melting in gutter and pavement applications. The CIT–1 aerial snow sensor detects falling or blowing precipitation before snow or ice begin to form, allowing the control to begin managing the system. The CIT–1 sensor may be roof or mast mounted and can be paired with the GIT–1 sensor for gutter applications or the SIT–6E sensor for pavement applications. All three sensors detect precipitation as snow at temperatures below 38°F (3.3°C). The PD Pro is signaled only if moisture occurs below this temperature, saving energy and ensuring thorough snow and ice melting. Since 1968, these sensors have been the industry’s most versatile and cost-effective automatic snow melting control sensors.

  • Self-testing Ground Fault Equipment Protection (GFEP)
  • Automatic and manual-override operator controls


  • Automatic snow and ice melting control minimizes operating costs
  • Rated for up to 7 amp inductive loads for pilot duty applications and resistive loads up to 30 amps
  • Weather-resistant NEMA 4X enclosure
  • C-UL-US Listed for Temperature Regulating Equipment
  • Adjustable Hold-On timer continues heater operation after snow and ice stop to ensure complete melting
  • Dual sensor capability to meet site performance requirements
  • Automatic and manual-override operator controls for changing environmental conditions
  • Optional remote control operation for added convenience


Area of use Nonhazardous locations
Protection NEMA 4X
Cover attachment Polycarbonate cover, machine screws

2 x 3/4″ entry (bottom right) for NEC Class 2 connections


3 x 1-1/6″ entries (bottom left and left) for supply and load power

Material Polycarbonate
Mounting Wall mounted
Dimensions 5 1/2″ (L) x 8 1/8″ (W) x4 3/8″ (H) / 140mm (L) x 207mm (W) x 112mm (H)
Weight 3 lbs (not including sensors)
Front Panel Interface
Status indicator SUPPLY (green): Power on
HEAT (yellow): Heating cycle in process
SNOW (yellow): Sensor(s) detect snow
Supply voltage 100 – 277 VAC; 50/60 Hz

7 amp maximum inductive


30 amp maximum resistive

Contact type 2 Form A
Maximum ratings Voltage: 277 VAC
Current: 30 amps
Heater Hold-On timer 0 to 8 hours; actuated by snow stopping or toggle switch
System test Switch toggles heater contact on and off. If temperature exceeds optional high limit thermistor (45°F), heater shuts off to reduce costs and prevent damage
Wire and Cable Ratings
Power cable Size for heater load (30 amp maximum)
Sensor wiring #18 AWG jacketed, 3-conductor
Heater cable Size for maximum heater load
Remote wiring #22 AWG jacketed, 2-conductor
Operating temperature −31°F to 113°F (−35°C to 45 °C)
Storage temperature −67°F to 167 °F (−55°C to 75 °C)
Snow/Ice Sensors
Maximum quantity 2 ETI sensors
Circut type NEC Class 2
Lead length

Up to 500′ (152m) using 18 AWG 3-wire jacketed cable


Up to 2,000′ (609m) using 12 AWG 3-wire jacketed cable


Order Number Description
23736 PD Pro
23735 PD Pro Installation and Operations Manual
21357 RCU-3 Remote Control (Optional)
19272 High-Temperature Sensor w/20′ (6m) lead (optional)
10001 CIT-1 Aerial Sensor
11351 GIT-1 Gutter Ice Sensor
20756 SIT-6E Pavement Mounted Snow and Ice Sensor

We're dedicated to our customers

From the front office to the production floor, we go above and beyond to help make your project successful.

We're dedicated to our customers

From the front office to the production floor, we go above and beyond to help make your project successful.

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