OVERVIEWsection II130207Visit our web site at www.neptronic.comII.1

OVERVIEWDisconnect switch2 knockoutsSlip-In type frameControlterminal blockLine voltageterminal blockStage fusesTransformerContactorfig.2.1Control panelProtective screenII.2Visit our web site at www.neptronic.com130207

DESCRIPTION OF COMPONENTSMagnetic ContactorProvides power to the individualstages of the heater.StandardSolid State Relay (SSR)Proportionally controls theamount of power transmitted tothe heating elements. Allowsquiet operation and is exceptionallyreliable.Standard for proportional heatersPneumatic Electric ControlConverts a proportional pneumaticcontrol signal to a proportionalelectric signal.Standard for proportional unitswith pneumatic signal130207TransformerSupplies power to the controlcircuit. Supplied with a fuse.StandardManual Reset ThermalCut-OutA secondary safety device whichremoves power to the elements ifoverheating occurs.Standard when required by code,otherwise optionalDisconnect SwitchCuts the power supply to theheater in order to safely performinstallation and maintenancetasks.Standard when required by code,otherwise optionalAutomatic Reset ThermalCut-OutAn automatic reset, primarysafety device. Removes powerfrom elements if overheatingoccurs.StandardNeptronic HECElectronic ControllerA unique control and safetycomponent. Controls and optimizesthe power transmitted to the heatingelements according to the ducttemperature and air flow.Standard for proportional heaters.FusesProtect the total load and/orthe individual heater stages.Standard when required bycode, otherwise optionalVisit our web site at www.neptronic.comAirflow SwitchSafety component used toprevent a heater from operatingif there is no airflow.Standard for ON/OFF heatersPneumatic Electric SwitchConverts a pneumatic ON/OFFsignal to an electric signal.Standard for heaters withpneumatic ON/OFF signalMercury ContactorProvides power to the individualstages of the heater. Allowsquiet, reliable operation.OptionalII.3

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MECHANICAL CONSTRUCTION130207Visit our web site at www.neptronic.comII.5

FRAMESlip-In Electric Heater - Type IThe slip-in type electric heaters are designed so that the entireframe can be inserted into the duct.Advantages of slip-in electric heaters:A system using a slip-in heater permits the installation of theentire ventilation duct system before the heaters becomeavailable. Retrofits are much simpler, smaller dimensionslip-in heaters require no extra supports.To order a Neptronic slip-in heater, specify the dimensions ofthe duct and the selection software will automatically calculatethe optimum heater dimensions.Installation:fig.2.2Allow for a proper sized opening on one side of the duct, see fig. 2.2, as well as installation clearances to avoid anyobstructions around the duct. The Neptronic slip-in heater has a standard 1" (25.4mm) flange on each side of thecontrol box and can be attached directly to the duct with sheet metal screws.Flanged Electric Heater - Type FFlanged heaters are designed so that the heater is an integralpart of the duct work. The heater frame is attached to matchingduct flanges, see fig. 2.3. Standard 1" (25.4mm) on the heaterframe are used to attach it to the duct.Flanged heater dimensions match the dimensions of the duct.Heaters requiring extra support or for large heaters, customflanges can be provided.fig.2.3Installation:The Neptronic electric heater comes with 1" (25.4mm) standard flanges installed around the frame and on each sideof the control box. It can be attached directly onto the duct with sheet metal screws.Note: Round collar option available with flanged electric heater type FII.6Visit our web site at www.neptronic.com130207

FRAMERound Collar optionRound collar electric heaters are available for installation onround duct systems with a standard diameter of 6" to 24"(152mm to 609mm). They are provided with one male and onefemale adapter for ease of installation.Installation:The Neptronic round collar electric heater comes with a 1"(25.4mm) extension on each side of the frame. The heater isattached directly onto the duct using sheet metal screws.fig.2.4Zero Clearance ConstructionAll Neptronic heaters are designed and approved for zero clearance to combustible material. Zero clearance construction means that there is no restriction on the distance between combustible materials and the section of the duct housingthe heater, or the heater itself. The control panel must be accessible for servicing.Horizontal or Vertical MountingNeptronic electric heaters are designed to be installed in either horizontal or vertical ducts. Please specify the airflowdirection with an H for horizontal and a V for vertical to ensure correct orientation of the components in the nfig.2.5standardfig.2.6Optional Accessories:Protective ScreensOptional protective screens are available to prevent accidental contact with the heating elements.Option 10 or 01: Protective screens on one side only - 10 left of the control panel, 01 right of the control panel.Option 11: Protective screens on both sides of the heater.130207Visit our web site at www.neptronic.comII.7

CONTROL PANELStandard Control PanelThe control panel attached to the heater exceeds the frame dimensions by 1" (25.4mm) on the top and bottom. Ifinstallation conditions do not allow for this standard extension a control panel with dimensions equal to the heaterframe can be provided.The standard extension of the control panel is to the left. If installation conditions do not permit the extension to theleft you must specify the direction for the extension of the control panel.Control Panel OptionsBottom Control PanelA bottom control panel can be supplied, when requiredfor easy installation and maintenance.This option is available for all heaters (Slip-in, flangedand round collar) of small dimensions.fig.2.7INSULATION 1” (25.4mm)Insulated Control PanelAn insulated control panel is recommended for high ducttemperatures.Insulation material, 1" (25.4mm) thick is installedbetween the panel and the hot area to prevent condensation on electrical components.fig.2.8Remote Control PanelIn certain cases it may be more convenient to install thecontrol panel remotely from the heater or in a separateroom. A remote control panel can be supplied uponrequest.fig.2.9II.8Visit our web site at www.neptronic.com130207

CONTROL PANELEnclosure Types (control panels)Nema 1(IP 10)Protected against accessNema 12(IP 52)Dust-protectedNema 4(IP 56)Protected againstsplashing waterNema 4X(IP 65)Protected against corrosion130207Enclosures constructed for indoor use to provide a degree of protection topersonnel against incidental contact with the enclosed equipment and to providea degree of protection against falling dirt.This enclosure type is standard on Neptronic electric heaters.Enclosures constructed (without knockouts) for indoor use to provide a degreeof protection to personnel against incidental contact with the enclosed equipment;to provide a degree of protection against falling dirt; against circulating dust, lint,fibers, as well as water spray and light splashing of liquids, water infiltration, oilor non corrosive liquid refrigerant.Enclosures constructed for either indoor or outdoor use to provide a degree ofprotection to personnel against incidental contact with the enclosed equipment;to provide a degree of protection against falling dirt, rain, sleet, snow, windblowndust, splashing water, and hose-directed water; and that will be undamaged bythe external formation of ice on the enclosure.Enclosures constructed for either indoor or outdoor use to provide a degree ofprotection to personnel against incidental contact with the enclosed equipment;to provide a degree of protection against falling dirt, rain, sleet, snow, windblowndust, splashing water, and hose-directed water, and corrosion; and that will beundamaged by the external formation of ice on the enclosure.The control panel and/or the electric heater are constructed in stainless steel forthis option.Visit our web site at www.neptronic.comII.9

SPECIAL ELECTRIC HEATERSSpecial electric heatersHeater with Cold SectionIn special cases a cold section in the air duct is required.For example, when air flow has been altered near the areawhere the heater is located. In this case the heater will bebuilt in order to adapt to this constraint.Specify the location and dimensions of the cold section(s)using the control panel as your reference point.(see fig. 2.10)fig.2.10Large HeatersHeaters whose dimensions exceed 40" (1.0m), will bereinforced by NEP to assure proper rigidity. Multiplethermal cut-outs will be installed and evenly distributed toobtain the same level of safety as for a standard sizeheater.In some cases, the large heater will be constructed in twosections to simplify the installation.fig.2.11Process HeatersSpecial application heaters for baking, drying or otherprocesses up to a temperature of 1,200ºF (648ºC) and1,000kW can be designed and built to NEP's provenstandards.fig.2.12II.10Visit our web site at www.neptronic.com130207

MATERIALS & DIMENSIONSMaterialsNeptronic heaters are manufactured with the appropriate galvanized steel gauge to assure rigidity and corrosionprotection.Neptronic heaters can be constructed with 304 stainless steel for special applications.Typical DimensionsType I (slip-in)Modulating electric heater onlyfig.2.13Type F (flanged)1” (24.5mm)BHCD1” (24.5mm)(38mm) 1-1/2”A1”W(24.5mm)fig.2.14Modulating electric heater onlyround collar option with type Ffig.2.15W: Width of air duct H: Height of air duct130207Visit our web site at www.neptronic.comModulating electric heater onlyII.11

HEATING ELEMENTSOpen Coil Elements - Model CStandard open coil elements are NiCr 60 (grade C).They are composed of 60% Nickel, 16% Chrome andthe balance is Iron. The maximum operating temperature is 1,850ºF (1,000ºC).For applications in a humid environment, we recommendthe optional NiCr 80 (grade A) elements. They arecomposed of 80% Nickel and 20 % Chrome (does notcontain iron). This will allow a maximum operatingtemperature of 2,100º F (1,150ºC) and installationwhere condensation may be present in the air duct.fig.2.16Standard Tubular Elements - Model TTubular elements are made of Incoloy 800 (Nickelalloy) tube with a diameter of 3/8" (9.5mm) containing aheating coil in magnesium oxide powder. Connectionsare made with two terminals (10-32).The U or W shape of the tubular elements is determinedby the heater dimensions.fig.2.17Option: Tubular element can be made in stainlesssteel upon requestFinned Tubular Elements - Model FFinned tubular elements are made of Incoloy 800(Nickel alloy) tube with a diameter of 3/8" (9.5mm)containing a heating coil in magnesium oxide powder.The tube is equipped with steel fins and available withstainless steel fins as an option to allow for moreefficient heat dissipation.Attachments are made with two terminals (10-32). TheU or W shape of the tubular elements is determined bythe heater dimensions.Option: Fins can be supplied in stainless steel uponrequestII.12Visit our web site at www.neptronic.comfig.2.18130207

HEATING ELEMENTSSelection GuideElement TypesOpen CoilStandard TubularFinned TubularAdvantages- Excellent heat dissipationDisadvantages- Minimal pressure drop- Elements in direct contact with air- More kilowatts per sq.ft.- Cannot be installed in dusty environments- Fast response time- Quick delivery- Cannot be installed in humid environments- Less sensitive to humidity and dust- Increase in pressure drop- Excellent mechanical resistance- Less heat dissipation- Suited for demanding environments- Heating element not in direct contactwith air-Good heat dissipationLess sensitive to humidity and dustSuited for demanding environmentsExcellent mechanical resistanceHeating element not in direct contactwith air- Slower response time- Less kilowatt per sq.ft.- Longer delivery- Increase in pressure drop- Slower response time- Less kilowatt per sq.ft.- Longer deliverytable 2.1Static Pressure Lossfig.2.19130207Visit our web site at www.neptronic.comII.13

SELECTION AND INSTALLATION TIPSCalculation of required capacityImperialkW MetricCFM x (T 2 - T 1) x 1.083413kW : Power in kWCFM : Air volume in cubic feet per minuteT 2 : Temperature of air leaving heater in FT 1 : Temperature of air entering heater in FP Q x (T 2 - T 1) x 1,213600P : Power in kWQ : Air volume in m3/hrT 2 : Temperature of air leaving heater in CT 1 : Temperature of air entering heater in CMinimum Air VelocityOpen Coil ElementsTubular Elementsfig.2.20fig.2.21II.14Visit our web site at www.neptronic.com130207

SELECTION AND INSTALLATION TIPSAir Flow ConditionsBasic rules: Allow a minimum distance of 48" (1.2m) between any obstacle or elbow and the electric heater. Airflow must be evenly distributed across the duct.If these basic rules are not respected overheating may result.If the electric heater is located too close to afilter or diffuser, 3 overheating areas mayoccur (fig. 2.22).fig.2.22If the electric heater is located too close toa fan, 2 overheating areas may occur(fig2.23).fig.2.23If the electric heater is located to close to anelbow, 1 overheating area may occur (fig. 2.24).fig.2.24If the electric heater is located too close to atransition, 2 overheating areas at the edgesof the heater may occur (fig 2.25).fig.2.25If one of these overheating conditions exists the life expectancy of the heating elements will be affected. Weadvise that the basic rules stated above be followed. If these conditions cannot be avoided, NEP can provide coldsections in the appropriate areas of the electric heater (see the section on special electric heaters fig.2.10).130207Visit our web site at www.neptronic.comII.15

SELECTION & INSTALLATION TIPSElectric Heater current calculationSingle phaseIEVEILVLPThree phasesDelta connection120V o