APS-4C

Automatic Snow/Ice Melting System Control integral GFEP

Features & Benefits

  • Automatic snow/ice melting control
  • Satellite contactor interface for larger system
  • Energy management computer (EMC) interface
  • Accommodates MI, constant wattage and self-limiting heaters
  • Multiple sensor capability
  • Advanced patented and patent pending ground fault protection
  • Heater hold-on and test capability
  • C-UL-US
  • Simple to install and operate
  • Low energy costs
  • Minimum energy costs
Snow Switch model APS-4C snow and ice melting control

Snow Switch model APS-4C snow and ice melting control

APS-4C Dimensional Drawing

APS-4C Dimensional Drawing

Description

APS-4C Datasheet C Series Manual Snow and Ice Sensor Datasheet

The APS-4C Snow Switch when used with one, or more, compatible sensors automatically controls snow/ice melting heaters for minimum energy costs. Applications include pavement, sidewalk, loading dock, roof, gutter and down spout snow/ice melting in commercial and industrial environments. The APS-4C is interchangeable with the earlier APS-4.

The adjustable hold-on timer continues heater operation for up to 10 hours after snow stops to ensure complete melting. The optional RCU–4 Remote Control Unit can be located where system operation can be conveniently observed. It duplicates many of the APS-4C front panel functions.

The APS–4C provides advanced patented and patent pending ground fault equipment protection (GFEP) as required by the USA and Canadian National Electric Codes. The GFEP automatically tests itself every time the heater contactors operate and once every 24 hours. The trip current can be set at 60 or 120 ma via a DIP an internal switch or retained at the 30 ma default value. As an aid to troubleshooting heater ground faults, the APS–4C provides an output that can indicate the ground current on a service person’s portable DVM.

The calibrated 40°F to 90°F (4°C to 32 °C) high limit thermostat prevents excessive temperatures when using constant wattage and MI heaters. It also permits safe testing at outdoor temperatures too high for continuous heater operation. The temperature sensor is included.

The APS-4C provides a complete interface for use in environments supervised by an energy management computer (EMC). This feature can also be used for general purpose remote control and annunciation.

All sensor and communications wiring is NEC Class 2. This simplifies installation while enhancing fire and shock safety. The APS-4C can interface up to six sensors from the CIT–1 product family. More sensors provides superior performance by better matching the controller to site performance requirements.

Specifications

General
Area of use Nonhazardous locations
Approvals
Enclosure
Protection NEMA 3R
Cover attachment Hinged polycarbonate cover, lockable
Entries 1 × 1-1/16″ entry (top) for NEC Class 2 connections
2 × 1-11/16″ entries (bottom) for supply and load power, except 277 VAC single phase
2 × 1-1/16″ entries (bottom) for supply and load power, 277 VAC single phase only
Material Polycarbonate
Mounting Wall mounted
Control
Supply ETI PN 22472: 208-240 VAC, 35 VA, 3-phase 50/60 Hz
ETI PN 22473: 277 VAC, 45 VA, single phase 50/60 Hz
ETI PN 22475: 277/480 VAC, 45 VA, 3-phase 50/60 Hz
ETI PN 22476: 600 VAC, 50 VA, 3-phase 50/60 Hz
Load ETI PN 22472: 208-240 VAC, 50 amp max. resistive
ETI PN 22473: 277 VAC, 40 amp max. resistive
ETI PN 22475: 277/480 VAC, 50 amp max. resistive
ETI PN 22476: 600 VAC, 50 amp max. resistive
Contact type 3 Form A
Maximum Ratings Voltage: 600 VAC
Current: 50 amps
Heater hold-on timer 0 to 10 hours; actuated by snow stopping or toggle switch
System test Switch toggles the heater contact on and off. If temperature exceeds high limit, heater cycles to prevent damage.
Ground Fault Equipment Protection (GFEP)
Set point 30 mA (default); 60 mA and 120 mA selectable by DIP switch
Automatic self-test Mode A: Verifies GFEP function before contactors operate
Mode B: Verifies GFEP and heaters every 24 hours
Manual test/reset Toggle switch provided for this function
Maintenance facility DC output proportional to ground current provided for troubleshooting the heater system
Snow/Ice Sensors
Sensor type Up to 6 sensor from the CIT–1 product family
Circuit 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
High Limit Thermostat
Adjustment range 40°F to 90°F (4°C to 32°C)
Dead band 1°F (0.6°C)
Sensor type Thermistor network
Circuit type NEC Class 2
Lead length Up to 500′ (152m) using 18 AWG 2-wire jacketed cable
Up to 1,000′ (504m) using 12 AWG 2-wire jacketed cable
Energy Management Computer (EMC) Interface
Inputs OVERRIDE ON (10 ma dry switch contact)
OVERRIDE OFF (10 ma dry switch contact)
Outputs SUPPLY (10 ma dry switch contact)
SNOW (10 ma dry switch contact)
HEAT (10 ma dry switch contact)
HIGH TEMP (10 ma dry switch contact)
ALARM (10 ma dry switch contact)
Environmental
Operating temperature −40°F to 160°F (−40°C to 71°C)
Storage temperature −50°F to 180°F (−45°C to 82°C)

ORDERING INFORMATION

Order Number Description
22472 APS–4C Control Panel, 208-240 VAC 50/60 Hz Three Phase
22473 APS–4C Control Panel, 277 VAC 50/60 Hz Single Phase
22475 APS–4C Control Panel, 277/480 VAC 50/60 Hz Three Phase
22476 APS–4C Control Panel, 600 VAC 50/60 Hz Three Phase
Accessories
21358 RCU–4 Remote Control (Optional)
19272 High Temperature Sensor w/ 20′ (6m) lead (Qty 1 included)
22690 PTS–100 Embedded Temperature Sensor (Optional)
Snow/Ice Sensors (Not Included)
10001 CIT–1 Aerial Snow Sensor
11351 GIT–1 Gutter Ice Sensor
20756 SIT–6E Pavement Mounted Snow/Ice Sensor
Satellite Contactors (Not Included)
22477 SC–40C Satellite Contactor, 208-240 VAC 50/60 Hz Three Phase
22478 SC–40C Satellite Contactor, 277 VAC 50/60 Hz Single Phase
22480 SC–40C Satellite Contactor, 277/480 VAC 50/60 Hz Three Phase
22481 SC–40C Satellite Contactor, 600 VAC 50/60 Hz Three Phase