MODULAR SNOW/ICE HEATER CONTROL SYSTEM
MODEL APS-3CAUTOMATIC SNOW/ICE MELTING SYSTEM CONTROL PANELMODEL APS-4CAUTOMATIC SNOW/ICE MELTING SYSTEM CONTROL PANELMODEL SC-40CMODULAR SNOW/ICE HEATER CONTROL SYSTEMSAFETYThis device provides Equipment Ground Fault Protection required byArticle 426.28 of the National Electrical Code. This device does notprovide Personnel (GFCI) Protection” or the equivalent.Make all electrical connections in compliance with the National ElectricalCode (NFPA 70) and local electrical code. If you have questionsconcerning the installation or application, contact Customer Service.ADDITIONAL INFORMATIONMore information is regularly made available through our website, www.networketi.com. Please visit us online for Data Sheets, Manuals, WhitePapers, technical articles, and more. The most current and up to dateversion of this and every other manual for our products can be foundin Acrobat (pdf) format to view online or to print. This is to assist you ininstalling and using our products to the best effect possible. If you haveany comments about this or any other product from ETI , please contactus.South Bend, Indiana USA networketi.comSNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
FIGURE 1. APS–4C DimensionalINTRODUCTIONAll APS “C” Series models provide a relay closure interface foruse with Energy Management Computers (EMC). This featurecan also be used for general purpose remote control andannunciation and other advanced applications.The APS “C” Series Snow Switch Control Panels, when usedwith compatible ETI , sensors, automatically control snow andice melting systems, ensuring complete melting for minimaloperating costs. Typical applications are pavement, sidewalk,loading dock, roof, gutter, and down spouts.Simple remote control features are also provided by the RCU–3Remote Control Unit for the APS–3C and the RCU–4 RemoteControl Unit for the APS–4C and SC–40C.The APS “C” Series continues the ETI , APS family of ControlPanels with the APS–3C Control Panel, the APS–4C ControlPanel, and the SC–40C Satellite Contactor. All three modelsimprove upon and extend the features of previous modelswhile maintaining backwards compatibility. The new APS “C”Series models are interchangeable with earlier APS models toensure the continued long life of existing systems.All sensor and communications wiring is NEC Class 2. Thissimplifies installation while enhancing fire and shock safety.WARNING: Do not over-tighten the Class 2 terminal blockscrew as this can result in an open/intermittent connection.The APS–3C and APS–4C can interface with up to six sensorsfrom the CIT–1 product family. More sensors provide superiorperformance by better matching the controller to siteperformance requirements. (The SC–40C does not make use ofsnow/ice sensors but rather is notified of snow conditions bythe master APS in the system.)The APS “C” Series offers voltage options from 120 VAC up to600 VAC. The APS–3C is available for 120 and 208–240 VAC andis optimized for inductive loads up to 24 amps, ideal for use inhydronic systems or with customer systems that provide a relayinterface. The APS–4C and the SC–40C are available for 208–600 VAC and are optimized for resistive loads up to 50 amps,with integrated ground fault equipment protection (GFEP).South Bend, Indiana USA networketi.com2SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
ENVIRONMENTAL INTERFACESSensors employ a heated interdigitated grid for moisturedetection. Heat melts frozen precipitation to form waterwhich is a better conductor of electricity. Circuits detectwater as a change in resistance between the fingers ofthe interdigitated grid. The temperature of the moisturesensor is regulated electronically.The APS “C” Series determines when to start heateroperation by monitoring the signals produced by up tosix customer supplied environmental sensors, paralleledtogether using a 3-wire bus. All sensors are Class 2 lowvoltage for safety reasons. Available sensors include: SIT–6E Pavement Mounted Snow and Ice SensorEach sensor has its own microcontroller for signalprocessing, logic and control. This enables the use of asimple 3-wire bus to connect sensors with the ControlPanel. Extension wire function and colors follow: CIT–1 Aerial Snow and Ice Sensor GIT–1 Gutter Snow and Ice SensorWhen used either alone or in combination, these sensorsaccurately determine whether snow and ice melting isrequired. This data is communicated back to either anAPS–3C or APS–4C Control Panel. Supply (Red)Sensors measure ambient temperature and detectmoisture in any form. Snow, sleet, freezing rain, etc., isassumed if moisture is present at temperatures below 38 F(3.33 C). Beginning heater operation at temperaturesslightly above freezing is essential to meeting customerexpectations. It takes a long time for snow to melt at 34 F.Sensors are wired together in parallel in a “wired OR”configuration. That is, red to red, white to white, and blackto black. When several sensors are connected in parallel,any sensor asserting a ground on the signal conductorenables snow melting heater operation. No ground onthe signal line indicates the absence of snow.Using several sensors improves snow melting effectivenessby compensating for environmental variations. Consider atypical pavement snow and ice melting system. Vehicularand pedestrian traffic in commercial environments oftenexpose the pavement to tracked slush and blowingor drifting snow. Because refreezing could create ahazardous situation, these hazards must be cleared. Thesolution is to combine several SIT–6E Pavement MountedSnow and Ice Sensors in expected pedestrian andvehicular pathways, along with a CIT–1 Aerial Snow andIce Sensor placed high in an open, unobstructed location,exposed to falling snow. One or more additional SIT–6Esensors might be needed in areas subject to drifting andblowing snow and/or melt water run-off and refreezing.APS “C” Series models include a temperature sensor formeasuring pavement slab or ambient air temperature.Its signal is used to provide an adjustable high limitthermostat function. This sensor, or a bypass resistor,is required for proper system operation. This featureis essential when using a potentially high temperatureheater such as MI cable. Signal (White) Ground (Black)HIGH LIMIT THERMOSTATThe calibrated 40 F to 90 F (4 C to 32 C) high limitthermostat prevents excessive temperatures when usingconstant wattage and MI heaters. It also permits safetesting at outdoor temperatures too high for continuousheater operation. The temperature sensor is included andmust be connected to the system for proper operation.The first sensor detecting freezing precipitation callsfor snow melting. The last sensor detecting frozenprecipitation signals the APS Control Panel thatprecipitation has stopped.South Bend, Indiana USA networketi.comThere are two DIP switch configurable operation modesfor the high limit thermostat. The factory default operationmode uses the high limit thermostat as a slab temperatureregulator, preventing heater operation at temperatures3SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
above the High Temperature Limit setting. The optionaloperating mode uses the high limit thermostat as anambient air sensor, preventing heater operation attemperatures above the High Temperature Limit settinguntil the temperature drops back to within the set limits.The details of operation in each mode are as follows:10 hours after snow stops. The additional operating timecompensates for the fact that there may be insufficientpower to both melt the snow as it falls and evaporate theresultant melt water.After normal operation has ended, the Hold-On Timerprovides a method for clearing tracked or drifting snowthat did not fall on a sensor. This can be accomplishedby either increasing the Hold-On Time or by manuallytoggling the heaters on for the Hold-On Time,independent of environmental conditions.SLAB REGULATING THERMOSTAT MODE High temperature causes unit to turn off heaters, ifrunning, and to ignore any call for heater operationfrom the panel, RCU, or EMC. High temperature continues any hold-on cycle that wasinitiated before the high temperature condition. If theslab temperature drops within limits during the hold-ontime, the heater will be turned back on.Lastly, the Hold-On Timer provides a method of safe heatertesting, that is independent of environmental conditions.The high limit thermostat ensures that this is the case. Inambient mode, at ambient temperatures above the highlimit, the manual Hold-On Time is reduced to 30 seconds.In pavement mode, at pavement temperatures above theHigh Temperature Limit, the heaters are disabled. In a high temperature condition, an APS will still initiateoperation of connected SC–40C contactor(s). The Heater Cycle functions normally.AMBIENT TEMPERATURE THERMOSTAT MODE High temperature causes unit to turn off heaters, ifrunning, and to ignore any call for heater operationfrom the panel, RCU, or EMC.INITIAL SETTINGSWhen first placing the system into service, the HoldOn Time should be set to an initial value; 3 to 5 hoursis suggested as a starting point. If the heaters turn offbefore the snow is completely cleared and the meltwater evaporated, increase the Hold-On Time by anhour or two. If the heaters operate for several hours afterthe pavement is clear and dry, decrease the Hold-OnTime by an hour. Continue this process until satisfactoryperformance is achieved. High temperature cancels any Hold-On cycle that wasinitiated before the high temperature condition. In a high temperature condition, an APS will not initiateoperation of connected SC–40C contactor(s). If the Heater Cycle switch is operated in a hightemperature condition, the heater(s) will be turnedon for a maximum of 30 seconds. A new Heater Cyclecannot be initiated for another two minutes after that.The small amount of energy wasted by a slightly excessiveHold-On Time is secondary to complete snow clearingand melt water evaporation. Incomplete operation isnot desirable because this can result in re-freezing meltwater which creates a slippery ice film.HOLD-ON TIMEThe adjustable Hold-On Timer provides three functionsaffecting heater operation. The Hold-On Timer is used tocontinue heater operation, to manually operate heaters,or to provide a limited heater cycle for testing.IF THE SYSTEM TURNS OFF TOO SOONIf the system turns off before the pavement is clear anddry, toggle the heaters on using the Hold-On Time switchon the front panel. Repeat as many times as is necessaryuntil the pavement is clear and dry. If the heaters remainoperating after the pavement is clear and dry, terminateDuring normal operation, the Hold-On Timer continuesheater operation for an adjustable time period of up toSouth Bend, Indiana USA networketi.com4SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
the Hold-On cycle with the Hold-On Time switch. Normaloperation resumes if it starts snowing during the HoldOn Time.interface provides five system status contact closuresfor the EMC including Supply, Snow, Heater, Alarm, andTemperature Limit.GROUND FAULT EQUIPMENT PROTECTION (GFEP)OPERATIONGFEP operates in the event of a deicing heater failureindicated by excessive leakage current to ground. Theleakage current equals the difference between theline and return currents flowing through the heaters. Aprecision current transformer measures the differencein currents. If the difference exceeds 30 mA, the heatercontactor drops out. This removes heater power, thuseliminating potential fire and electric shock hazards.Absent signals from the EMC, the APS Control Panelcontrols the heaters based on environmental conditions.Automatic snow melting control is the default conditionof the system.APS–3C FRONT PANELThe APS–3C has indicators, adjustments, and a switchfor local control of the snow melting system. Indicatorsinclude LED lights for Supply, Snow, Heat, EMC, TempLimit, and GFEP (NOTE: Ground Fault EquipmentProtection is not available on the APS-3C even thoughthere is an indicator light for it.). Adjustments providedallow for the calibrated adjustment of system Hold-OnTime from 0 to 10 hours (or Off) and Temp Limit for theHigh Temperature Limit adjustment with a range of 40 to90 F (4 to 32 C). The Heater Cycle toggle switch allowsfor the manual starting and stopping of a Heater Cycle.Sometimes, longer length and/or higher voltage heaterscause nuisance GFEP operation. This is true even thoughthe heaters are operating properly. Increasing the GFEPoperating current can correct this problem. A DIP switchcan increase the operating current from a default value of30 to 60 or 120 mA.Restoring heater operation requires operating the GFEPReset switch on the front of the Control Panel. This startsa sequence of events beginning with testing the GFEP tomake certain that it operates properly. If it is inoperative,the GFEP condition persists. Otherwise, the heatercontactor is energized. If excessive ground current flows,the GFEP drops the contactor and waits for operation ofthe Reset switch. Otherwise, the contactor is operatedonly if there is a call for heat.Figure 2 shows the APS–3C front panel layout.APS–4C FRONT PANELThe APS–4C has indicators, adjustments, and a switchfor local control of the snow melting system. Indicatorsinclude LED lights for Supply, Snow, Heat, EMC, TempLimit, and GFEP. Adjustments provided allow for theThe GFEP checks itself and the deicing heaters every24 hours, independent of environmental conditions.Operating the GFEP Test switch performs the samefunction. In addition, the GFEP function is tested eachtime the heater control contactor operates.ENERGY MANAGEMENT COMPUTER (EMC) INTERFACEThe APS “C” Series interfaces with an EMC via relays.Inputs from the EMC include Override On, which causesheater operation, and Override Off, which inhibits heateroperation. These functions are independent of weatherconditions and the status of the Hold-On Timer. TheSouth Bend, Indiana USA networketi.comFIGURE 2. APS–3C front panel detail5SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
calibrated adjustment of system Hold-On Time from 0 to10 hours (or off) and Temp Limit for the High TemperatureLimit adjustment with a range of 40 to 90 F (4 to 32 C).There are two toggle switches. The GFEP Test toggleswitch toggles up to Reset a ground fault condition andtoggles down to Test the ground fault circuitry. The HeaterCycle toggle switch permits manual starting and stoppingof a Heater Cycle.It adds remote control and status display to the APS–3Ccontrol at a location convenient to personnel capable ofobserving snow melting system operation.Figure 3 shows the APS–4C front panel layout.RESETTESTSC–40C FRONT PANELThe SC–40C has indicators, adjustments, and a switchfor local control of the snow melting system. Indicatorsinclude LED lights for Supply, Snow, Heat, EMC, TempLimit, and GFEP. Adjustments provided allow for thecalibrated adjustment of system Hold-On Time from 0 to10 hours (or Off) and Temp Limit for the High TemperatureLimit adjustment with a range of 40 to 90 F (4 to 32 C).There are two toggle switches. The GFEP Test toggleswitch toggles up to Reset a ground fault condition andtoggles down to Test the ground fault circuitry. The HeaterCycle toggle switch allows for the manual starting andstopping of a Heater Cycle.GFEPTESTFIGURE 4. SC–40C front panel detailSnow, slush, or ice, whether alone or incombination, must contact at least one sensorto start melting. Heater operation continuesuntil all sensors are dry. Depending on the rate of fall,snow density, wind velocity, power density, and otherfactors, heater operation must continue for a periodof time after the last sensor dries off. Slush tracked byvehicle and pedestrian traffic, along with blowing anddrifting snow, are problems that are hard to predict.Figure 4 shows the SC–40C front panel layout.RCU–3 REMOTE CONTROL UNITThe RCU–3 Remote Control Unit is used with the APS–3C.The cycle timer in the APS–3C begins when the lastsensor dries off and continues for an adjustable period ofup to 10 hours to keep the heaters operational until thepavement is completely dry. Otherwise, residual watercould re-freeze and create a hazardous condition.The RCU–3 provides a 2-, 4-, 6-, or 8-hour Cycle Timeadjustment that is independent of the APS–3C cycletime. This allows treatment of the condition requiring anadditional heater cycle as the exception rather than therule in order to minimize energy use.Operating the Heater Cycle switch operates heatersfor the Cycle Time which is normally set for 2 hours.Operating the Heater Cycle switch during the cycle timestops the timer. If the pavement or ambient temperatureexceeds the APS–3C High Temperature Limit setting, theRESETTESTGFEPTESTFIGURE 3. APS–4C front panel detailSouth Bend, Indiana USA networketi.com6SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
heater duty cycle is reduced or disabled to prevent overheating.Status indicators include Supply and Heat. These perform the samefunctions as those on the APS–3C.Figure 5 shows the RCU–3 layout.RCU–4 REMOTE CONTROLThe RCU–4 Remote Control Unit is used along with theAPS–4C and SC–40C. It adds remote control and status displayto the APS–4C or SC–40C controls at a location convenient topersonnel capable of observing snow melting system operation.Snow, slush or ice, whether alone or in combination, must contactat least one sensor to start melting. Heater operation continuesuntil all sensors are dry. Depending on the rate of fall, snow density,wind velocity, power density, and other factors, heater operationmust continue for a period of time after the last sensor dries off.Slush tracked by vehicle and pedestrian traffic, along with blowingand drifting snow, are problems that are hard to predict.The cycle timer in the APS–4C and SC–40C begins when the lastsensor dries off and continues for an adjustable period of upto 10 hours to keep the heaters operating until the pavement iscompletely dry. Otherwise, residual water could re-freeze andcreate a hazardous condition.The RCU–4 provides a 2-, 4-, 6- or 8-hour Cycle Time adjustmentthat is independent of the APS–4C and SC–40C cycle times. Thisallows treatment of the condition requiring extra heating as theexception rather than the rule thus minimizing energy use.Operating the Heater Cycle switch operates heaters for the CycleTime which is normally set for 2 hours. Operating the HeaterCycle switch during the cycle time stops the timer. If the pavementor ambient temperature exceeds the APS–4C or SC–40C HighTemperature Limit setting, the heater duty cycle is reduced ordisabled to prevent overheating.FIGURE 5. RCU–3 (above), RCU–4Status indicators include Supply and Heat. These perform the samefunctions as those on the APS–4C.The GFEP switch performs the same functions and operates in thesame manner as those on the APS–4C and SC–40C. In the event ofan unacknowledged GFEP, the Heat indicator flashes.Figure 5 shows the RCU–4 layout.South Bend, Indiana USA networketi.com7SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
OPERATIONas energy savings are being traded for an increasedlikelihood of refreezing.APS–3CThe snow melting system can be controlled and monitoredeither locally from the APS–3C itself or from two remotelocations including: The High Temperature Limit adjustment sets themaximum deicing temperature.Switches The Heater Cycle switch momentarily toggled downwill start a manual Heater Cycle for the Hold-On Timesetting or restart the Heater Cycle if one was in progress.Momentarily toggled up will cancel a Heater Cycle ifone is in progress. RCU–3 Remote Control Unit EMCLOCAL CONTROL FROM THE APS–3CIndicators SUPPLY (green) shows that power is present.REMOTE CONTROL FROM THE RCU–3 SUPPLY (green, blinking) means either the pavementtemperature sensor is missing from the system or isnot functioning. The pavement temperature sensor isincluded and must be connected to pins 10 and 11 forproper operation.Indicators SUPPLY (green) shows that power is present. HEAT (yellow) shows that there is a call for heat. Thishappens during snow and for the Hold-On Timethereafter or when the heater cycle switch is operated. SNOW (yellow) shows that there is a snow/ice signaloriginating from at least one of the CIT–1, GIT–1, and/orSIT–6E sensors attached to the system.Adjustments Cycle Time adjustment sets the time heaters will operatewhen the Heater Cycle switch is momentarily depressedat the RCU–3. HEAT (yellow) shows that there is a call for heat. Thishappens during snow and for the Hold-On Timethereafter or when the Heater Cycle switch is operatedSwitches Heater Cycle switch momentarily depressed will starta manual Heater Cycle for the Cycle Time setting.Momentarily depressed while heaters are beingoperated by a Hold-On Timer or during manual HeaterCycle will end the Heater Cycle. Heater operation duringsnow conditions cannot be canceled in this manner. EMC (yellow) shows that the interfaced EnergyManagement Computer is presently overriding localsystem control. TEMP LIMIT (red) shows that either the pavementtemperature is above the set High Temperature Limitand there is a call for heat or the ambient air temperatureis above the High Temperature Limit setting. The APS–3C can be configured to monitor slab temperature orambient air temperature but not both.REMOTE CONTROL FROM THE EMC INTERFACEThe EMC interface is identical on all of the APS “C” Seriesmodels. Please see the EMC section of this manual forinterface details.Adjustments The Hold-On Time adjustment sets the time that heatersoperate after snow stops. Doing this is necessaryto make certain the pavement dries before heatingceases. This prevents refreezing. Try an initial setting of3 to 5 hours. Increase, if necessary. Reduce with careSouth Bend, Indiana USA networketi.comAPS–4C AND SC–40CThe snow melting system can be controlled and monitoredeither locally from the APS–4C itself or from two remotelocations connected to the APS Control Panel including: RCU–4 Remote Control Unit8SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
EMCoperate after snow stops. Doing this is necessaryto make certain the pavement dries before heatingceases. This prevents refreezing. Try an initial setting of3 to 5 hours. Increase, if necessary. Reduce with careas energy savings are being traded for an increasedlikelihood of refreezing.Control initiated from an SC–40C is local to the heater(s)connected to that panel and will not affect the operationof heaters attached to the APS Control Panel or otherSC–40C Satellite Contactor in the system. This includesremote control operation from an RCU–4 or EMCconnected to an SC–40C. High Temperature Limit adjustment sets the maximumdeicing temperature.LOCAL CONTROL FOR THE APS–4C OR SC–40CSwitches The GFEP Test switch momentarily toggled down willstart a test of the ground fault circuitry of that APS–4Cor SC–40C. Momentarily toggled up will Reset a groundfault condition at that APS–4C or SC–40C.Indicators SUPPLY (green) shows that power is present. SUPPLY (green, blinking) indicates that either thepavement temperature sensor is missing from thesystem or is not functioning. The temperature sensor isincluded and must be connected to pins 10 and 11 forproper operation. The Heater Cycle switch momentarily toggled downwill start a manual heater cycle for the Hold-On Timesetting or restart the Heater Cycle if one was in progress.Momentarily toggled up will cancel a heater cycle if oneis in progress. SNOW (yellow) shows that there is a snow/ice signaloriginating from at least one of the connected CIT–1,GIT–1, and/or SIT–6E sensors attached to the system. HEAT (yellow) shows that there is a call for heat.This happens during snow and for the hold-on timethereafter or when the heater cycle switch is operated.REMOTE CONTROL FROM THE RCU–4 EMC (yellow) shows that the interfaced EnergyManagement Computer is presently overriding localsystem control. HEAT (yellow) shows that there is a call for heat. Thishappens during snow and for the Hold-On Timethereafter or when the Heater Cycle switch is operated.Indicators SUPPLY (green) shows that power is present. TEMP LIMIT (red) shows that either the pavementtemperature is above the High Temperature Limitsetting and there is a call for heat or the ambient airtemperature is above the High Temperature Limitsetting. The APS–4C can be configured to monitorambient air temperature or slab temperature butnot both.Adjustments Cycle Time adjustment sets the time the heaters willoperate when the Heater Cycle switch is momentarilydepressed at the RCU–4. GFEP (red, blinking) shows that there is a ground faultcondition present on an attached SC–40C SatelliteContactor.Switches The GFEP Test/Reset switch momentarily depressedwhen there is no ground fault condition will start a testof the ground fault circuitry of that APS–4C or SC–40C.Momentarily depressed when there is a ground faultcondition at the attached APS–4C or SC–40C will Reseta ground fault condition at that APS–4C or SC–40C andstart a test of the ground fault circuitry of that APS–4C orSC–40C.Adjustments Hold-On Time adjustment sets the time that heaters The Heater Cycle switch momentarily depressed willstart a manual Heater Cycle for the Cycle Time setting. GFEP (red) shows that there is a GFEP condition presenton the local APS–4C Control Panel or SC–40C SatelliteContactor.South Bend, Indiana USA networketi.com9SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
Momentarily depressed while heaters are beingoperated by a Hold-On Timer or during manual HeaterCycle will end the Heater Cycle. Heater operation duringsnow conditions cannot be canceled in this manner.APS “C” Series Control Panel in order to turn heaterson. A normal contact closure will turn on heaters untiloperation is cancelled. If the EMC cycles the Override Onrelay on and off again within more than 32 milliseconds,but less than 300 milliseconds, the attached APS “C”Series Control Panel will begin a manual Heater Cycleand run for the Hold-On Time setting.REMOTE CONTROL FROM THE EMC INTERFACEThe EMC interface is identical on all of the APS “C”Series models. Please see the EMC section below forinterface details. OVERRIDE OFF can be used to override an attachedAPS “C” Series Control Panel in order to turn heatersoff. A normal contact closure will turn off heaters. If theEMC cycles the Override Off relay on and off againwithin more than 32 milliseconds, but less than 300milliseconds, the attached APS “C” Series Control Panelwill end a manual Heater Cycle. If both override on andOverride off are closed (selected) the override off willtake precedence.ENERGY MANAGEMENT COMPUTER (EMC) INTERFACEThe APS “C” Series provides an EMC interface tocommunicate with the EMC of building automationsystems. The EMC interface provides 10 mA dry switchcontacts for communicating status to the EMC or startingor stopping the system from the EMC. Refer to Figure 20for EMC connections.EMC INTERFACE OUTPUTS Output Common HEAT indicates that there is a call for heat. This happensduring snow and for the Hold-On Time thereafter orwhen the heater cycle switch is operated. SNOW indicates that there is a snow/ice signaloriginating from at least one of the connected CIT–1,GIT–1, and/or SIT–6E sensors attached to the system. ALARM - Indicates ground fault alarm. SUPPLY indicates that power is present. TEMP LIMIT indicates that either the pavementtemperature is above the High Temperature Limit settingand there is a call for heat or the ambient air temperatureis above the High Temperature Limit setting. An APS “C”Series Control Panel can be configured to monitor slabtemperature or ambient air temperature but not both.FIGURE 6. Location of DIP SwitchEMC INTERFACE INPUTS OVERRIDE ON can be used to override an attachedSouth Bend, Indiana USA networketi.com10SNOW/ICE CONTROLS INSTALLATION MANUAL PART NO. 22862 REV 0.0
SPECIFICATIONSAll Specifications apply to APS–3C, APS–4C and SC–40C panels unless stated otherwise.GeneralArea of useNonhazardous locationsApprovalsEnclosureProtectionNEMA 3RCover attachmentHinged polycarbonate cover, lockableEntriesAPS–3C: 3 1-1/16” entriesAPS–4C and SC–40C: 1x1/16” entry (top) for NEC Class 2 connections2x1-11/16” entries (bottom) for supply and load power (except for 277 VAC Single Phase)MaterialPolycarbonateMountingWall mountedControlSupplyAPS–3C: ETI PN 22470: 120 VAC, 50/60 Hz, 35 VA,ETI PN 22471: 208-240 VAC, 50/60 Hz, 35 VA,APS–4C: ETI PN 22472: 208-240 VAC, 35 VA, three phase 50/60 HzETI PN 22473: 277 VAC, 45 VA, single phase 50/60 HzETI PN 22475: 277/480 VAC, 45 VA, three phase 50/60 HzETI PN 22476: 600 VAC, 50 VA, three phase 50/60 Hz,SC–40C: ETI PN 22477: 208-240 VAC, 35 VA, three phase 50/60 HzETI PN 22478: 277 VAC, 45 VA, single phase 50/60 HzETI PN 22480: 277/480, 45 VA, three phase 50/60 HzETI PN 22481: 600 VAC, 50 VA, three phase 50/60 HzLoadAPS–3C: ETI PN 22470: 120 VAC, 24 amp max. inductiveETI PN 22471: 208-240 VAC, 24 amp max. inductiveAPS–4C: ETI PN 22472: 208-240 VAC, 50 amp max. resistiveETI PN 22473: 277 VAC, 40 amp max. resistiveETI PN 22475: 277/480 VAC, 50 amp max. resistiveETI PN 22476: 600 VAC, 50 amp max. resistive,SC–40C: ETI PN 22477: 208-240 VAC, 50 amp max. resistiveETI PN 22478: 277 VAC, 40 amp max. resistiveETI PN 22480: 277/480, 50 amp max. resistiveETI PN 22481: 600 VAC, 50 amp max. resistiveContact typeAPS–3C: Form C, APS–4C and SC–40C: 3 Form AMaximum RatingsAPS–3C: Voltage: 240 VACCurrent: 24 ampsAPS–4C and SC–40C: Voltage: 600 VACCurrent: 50 ampsHeater hold-on timer0 to 10 hours; actuated by snow stopping or toggle switchSystem testSwitch toggles the heater contact on and off. If temperature exceeds high limit,heater cycles to prevent damage.South Bend, Indiana USA networketi.com11SNOW/ICE CONTROL
Snow and Ice Sensors in expected pedestrian and vehicular pathways, along with a CIT–1 Aerial Snow and Ice Sensor placed high in an open, unobstructed location, exposed to falling snow. One or more additional SIT–6E sensors might be needed in areas subject to drifting and blowing snow and/or melt water run-off and refreezing.
Snow Clearing: The moving of accumulated snow from the surface of a defined service area. Synonyms: Snowplowing, or Snow Pushing. Snow Dump: A defined area to store large amounts of snow from one or many sites. Synonyms: Snow Field, Snow Farm. Snow Hauling: Part of the Snow Removal process, it is the act of transporting snow and other winter
snow event is not necessarily a single large snow storm. A snow event can be a series of storms that result in additional snow loads . on a building. No two snow events are identical, and the resulting snow loads on nearby buildings from one snow event may be different. One foot of snow on the ground does not necessarily equal 1 foot of snow on .
Fleetguard Cross Reference Guide. OBSOLETED PARTS Obsolete Part # Replacement Part # Filter Part Type 3896692 N/A Coolant Heater 3896694 N/A Coolant Heater 3896697 N/A Coolant Heater 3896700 N/A Coolant Heater 3896706 N/A Coolant Heater 3305648 N/A Coolant Heater 3306006 N/A Coolant Heater 3306007 N/A Coolant Heater 3307046 N/A Coolant Heater
The Snow Switch model GF Pro snow and ice control is designed for use with up to two compatible sensors. Compatible sensors include the CIT–1, GIT–1, and SIT– 6E snow and ice melting sensors. These sensors have provided the industry’s most versatile and cost effective snow melting control when used with Environmental Technology control .
This heater is equipped with a tip-over safety feature. Once the heater is tipped over, an internal switch will automatically shut the heater off. Once the heater is restored an upright position, the heater will reset. To continue operation, turn on the heater using the supplied remote control or the control panel on the heater.
FrostGuard is designed to remove melt water, not accumulated snow. FrostGuard heating cable will not keep snow or ice from falling off the roof. Snow fences or snow guards should be used to eliminate snow movement. For the names of manufacturers of snow guards or snow fences, contact Pentair Thermal Building Solutions at (800) 545-6258.
relatively flat land. Alpine glaciers form on top of high mountains. 4. Snow falls on an area but does not melt over the course of the year. Over time, more snow builds up in the area. The weight of the snow above pushes down on the snow below, causing the snow at the bottom to turn into ice. This ice is a glacier. 5.
R&D projects, but there are doubts on how many innovations have effectively gone to the market. The mid-term evaluations show outputs and results coming out of collective actions and support to regional filières and clusters. 2011 is the first year with outputs in the field of
