Failure to comply can result in explosion or fire. Hazardous area terminal housings are available, consult your Local Chromalox representative for details. The NWHMT series is a general-purpose water circulation heater intended for use indoors. The three Copper sheathed tubular elements are centered in a 21/ 2” diameter galvanized heating chamber and sealed in a removable screwplug. The assembly is surrounded by 1-1/2” insulation and sheet metal jacket. Depending upon the specifications, the NWH

WARNING: Hazard of Electric Shock and Thermal Burns. These troubleshooting checks should only be performed by qualified personnel after review of the Installation and Operating Instructions for your specific Chromalox Electric Steam Boiler. For convenience, we have outlined a brief description of typical malfunctions and the area that should be explored in order to make the proper correction. This is followed by a detailed analysis of the five areas listed above. TYPICAL MALFUNCTIONS & PROPER CO

WARNING: It is the responsibility of the purchaser of the heater to make the ultimate choice of sheath material based upon his knowledge of the chemical composition of the corrosive solution, character of the materials entering the solution, and controls which he maintains on the process. Chromalox cannot warrant any electric immersion heater against failure by sheath corrosion if such failure is the result of operating conditions beyond our control. 1. Heater Construction Characteristics A. Hig

B. Avoid contact between heater and combustible material. C. Keep combustible materials far enough away to be free of the effects of high temperatures. © 2010 Chromalox, Inc. WIRING CAUTION: Hazard of Electric Shock. Any installation involving electric heaters must be effectively grounded in accordance with National Electrical Codes to eliminate shock hazard. 1. Electrical wiring to heater must be installed in accordance with the National Electrical Code and local electric codes. 2. When element

Although the safety of the installation is the responsibility of the user, Chromalox will be glad to make equipment recommendations. INSTALLATION WARNING: Hazard of Shock. Disconnect all power before installing heater. 1. Vertical Mounting (Preferred) — When the heater is vertically mounted, the terminal housing will be at the top of the heater. The water inlet pipe will be located on the side near the bottom of the heater and the outlet pipe at the top. The axis of the chamber will be in a vert

3. Power controllers must be used when heaters are rated 3 phase and when the heater amperage exceeds the rating of the thermostat. 4. Refer to Wiring Diagram, Table B, for the proper wiring diagram for connecting heater. Model 240V, 1 O Fig. 240V, 3 O . Fig. 480V, 1 O . Fig. 480V, 3 O . Fig. NWH-3625 NWH-3925 NWH-31225 NWH-31525 NWH-31825 2 2 2 2 2 1 1 1 1 1 2 2 2 2 2 1 1 1 1 1 Figure 1 240V, 480V 3O. Figure 2 240V, 480V, 1O Use contactor when the heater amperage exceeds the rating of the therm

materials entering the solution as well as the cor 3. If foreign material is carried by the liquid flow, install suitable rosive effect of the solution upon the heating ele filters in the inlet pipe line to the heater. ments and chamber. Chromalox cannot warrant 4. Do not allow heater to operate when liquid flow is interrupted. MAINTENANCE 1. WARNING: Hazard of Electric Shock. Disconnect all 3. Periodically check temperature control and limit control operpower before servicing heater. ation to i

6 47.7 32-15/16 22-1/2 16-1/2 NWH-3925 240 1 or 3. 9 47.5 32-15/16 22-1/2 16-1/2 NWH-31225 or 1 or 3. 12 46.2 42-15/16 32-1/2 26-1/2 NWH-31525 480 1 or 3. 15 45.9 55-7/16 45 39 NWH-31825 1 or 3. 18 45.6 55-7/16 45 39 GENERAL The NWH-3 series is a general-purpose water or water-based thermostat. Such thermostats function to control outlet tempera- solution circulation heater intended for use indoors. It is designed tures and to limit internal temperatures under abnormal flow con- for 150 psig at