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

6. If the fitting is used thru an opening* use the locknut and plastic washer to fasten it. * Opening for 1/2” NPT thread is 7/8”. OPERATION 1. Do not operate heater at voltages in excess of that stamped on the heater since excess voltage will shorten heater life. 2. Always maintain a minimum of 2” of solution above the heated portion of the element to prevent exposure of the effective heated length. If the heater is not properly submerged, it may overheat and shorten heater life. Do not operate

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 550°F per ANSI standards. ditions. These controls d

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

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

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Circuit Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model No. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . No. of Power Circuits . . . . . . . . . . . . . . . Amps. . . . . . . . . . . . . . . . . . . . Electrical Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control

______________________________________________ Power Circuit Voltage __________________________ Model No. ___________________________________________________ Control Circuit Voltage__________________________ National Board No. ____________________________________________ Amps ___________Phase __________Cy __________ IMPORTANT – This data file contains the National Board Registration Certificate approving your boiler. It must be kept near the boiler at all times. Model Electric Capacity BHP Ratin

9 155-024796-009 300-057560-007 300-048481-006 NWH-31225 240 1 12 155-024796-011 300-057560-007 300-048481-006 NWH-31225 240 3. 12 155-024796-012 300-057560-007 300-048481-006 NWH-31225 480 1 12 155-024796-013 300-057560-007 300-048481-006 NWH-31225 480 3. 12 155-024796-014 300-057560-007 NWH-31525 240 1 15 155-024796-016 300-057560-007 300-048481-006 NWH-31525 240 3. 15 155-024796-017 300-057560-007 300-048481-006 NWH-31525 480 1 15 155-024796-018 300-057560-007 300-048481-006 NWH-31525 480 3.