Assessments - 2, GPA: 5
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3O Circuits Dimensions (In.) A B C D E NWHO-4590 NWHO-45125 NWHO-45150 NWHO-45175 NWHO-45200 240 or 480 240 or 480 240 or 480 240 or 480 240 or 480 90 125 150 175 200 5 5 5 5 5 721/2 871/2 1021/2 1171/2 125 251/2 251/2 251/2 251/2 251/2 635/8 785/8 935/8 1085/8 1161/8 1813/16 1813/16 1813/16 1813/16 1813/16 121/2 121/2 121/2 121/2 121/2 NWHO-77220 NWHO-77225 NWHO-77250 240 or 480 240 or 480 240 or 480 200 225 250 6 6 6 971/2 1051/2 1131/2 273/4 273/4 273/4 885/8 965/8 1045/8 19 19 19 133/4 133/4 133/4 NWHO-108300 NWHO-108325 NWHO-108350 240 or 480 240 or 480 240 or 480 300 325 350 6 6 6 981/2 1041/2 1101/2 291/2 291/2 291/2 895/16 955/16 1011/16 193/8 193/8 193/8 141/2 141/2 141/2 These Dimensions are typical. Check factory for dimensions of a particular unit. GENERAL The high capacity NWHO-45, 72 or 108 series are intended for indoor use and are used primarily for oil heating. The 45, 72 or 108 steel sheathed tubular elements are centered in a 14”, 16” or 18” diameter steel heating chamber, respectively, and welded to a removable steel flange. The assembly is surrounded by 2” of insulation and a sheet metal jacket. Depending upon the order specifications, the NWHO-45, 72 or 108 may or may not be factory equipped with an MF2 or other Chromalox thermostat. Such thermostats function to control outlet temperatures and to limit internal temperatures under abnormal flow conditions. These controls do not fail-safe. CAUTION: Users should install adequate back-up controls and safety devices with their electric heating equipment. Where the consequences of failure may be severe, back-up controls are essential. Although the safety of the installation is the responsibility of the user, Chromalox will be glad to make equipment recommendations. INSTALLATION 1. Vertical mounting (axis of chamber Figure A should be bolted solidly; however, the remaining lug should be vertical) is preferred. Check factory bolted loosely to allow freedom of movement with expansion. for constructions suitable for hori 5. DANGER: Hazard of Fire. Provide minimum of 6” spaczontal mounting. ing from chamber and related piping to nearest combustible 2. Mount heater with terminal enclomaterial. Avoid operation of heater near combustible fluids or sure at top, and use lower nozzle as in combustible vapor or gas laden atmosphere. Note: Contact inlet to the circulating fluid. factory for heaters suitable for use in hazardous locations. 3. The NWHO-45, 72 and 108 series 6. Provide adequate space at terminal end to permit withdrawal of of circulation heaters are provided the heater from chamber should servicing be required. with mounting lugs to support the 7. If two or more heaters are needed to provide the needed heat- heater chamber. Refer to Figure A ing capacity, arrange them for series flow. for one suggested mode of support. 8. DANGER: Possible Explosion. A pressure relief valve 4. Mount heaters to permit unreshould be provided by customer at outlet of vessel. There strained expansion of chamber due should be no valving between vessel and relief valve. to temperature. The large flange lug © 2010 Chromalox, Inc. WIRING CAUTION: Hazard of Electric Shock. Any installation involving electric heaters must be grounded to earth to eliminate shock hazard. 1. Electric wiring to heater must be installed in accordance with National Electrical Code and with local codes. 2. Because of high operating temperatures expected, aluminum wiring is not recommended. 3. Refer to Wiring Diagram Figure B for the typical wiring used for connecting the NWHO-45 series heater. 4. Three 3 phase circuits is a typical design for these heaters. Other circuit arrangements are often supplied depending upon customer specifications or amperage rating. 1L11L21L32L12L22L33L13L23L3Over-TempCutout120Vor240VThermostatContactorFusesFusesFusesContactorContactor Figure B OPERATION 1. Do not heat materials that are corrosive to the heating element sheath or chamber. WARNING: Type NWHO Circulation Heaters are equipped with steel heating elements and galvanized- steel heating chambers. It is the responsibility of the user to know the chemical composition of the corrosive solution and the character of the materials entering the solution as well as the corrosive effect of the solution upon the heating elements and chamber. Chromalox cannot warrant any electric circulation heater against failure by sheath corrosion if such failure is the result of operating conditions beyond our control. 2. Terminal ends of heater must be protected from drippings, condensation, spray or direct spill-over of material whose presence at the terminals may damage heater electrical insulation. Liquid-tight terminal enclosures are available to protect heater. Check Factory. 3. If foreign material is carried by the fluid flow, install suitable filters in the inlet pipe line to the heater. 4. Do not allow heater to operate when oil flow is interrupted. MAINTENANCE 1. CAUTION: Hazard of Electric Shock. Disconnect all power...