TM 10-7310-241-12&P                                                                                                                                                Change  1     1-3 Section I.  GENERAL INFORMATION 1-1.SCOPE a.  Type of Manual.  Operator’s and Unit Maintenance Manual including Repair Parts and Special Tools List. b.  Model Number and Equipment Name.  Heater, Water and Ration (HWR): 7310-01-387-1305 for Models RAK-15 and 471012.    NOTE This technical manual, TM 10-7310-241-12&P, contains two distinctly different models of the HWR each with their own separate model numbers.   Please be aware that when performing maintenance procedures or ordering replacement parts you will need to find the corresponding information for either Model RAK-15 or Model 471012.  The current NSN for both models is 7310-01-387-1305. c.  Purpose of Equipment.     (1)  The HWR provides a mounted potable water and prepackaged rations heating facility for the crew of any military vehicle, which has a 22 - 28 V  dc (24 V  dc nominal) electrical system. Operation is possible at any time (including full battle conditions) in any climate while stationary or mobile.     (2)  When used for water only, the HWR heats approximately one gallon of potable water for beverages, hygiene or medical Purposes.     (3)  When used for rations the HWR heat up to five unopened MRE entrees together with 40 fluid ounces of potable water.     (4)  With the cover closed and locked the HWR can keep the contents hot for as long as operationally required. 1-2.  MAINTENANCE FORMS AND PROCEDURES Department of the Army forms and procedures used for equipment maintenance will be those prescribed by DA PAM 738-750 (The Army Maintenance Management System (TAMMS)) as contained in the Maintenance Management Update. 1-3.  SAFETY, CARE AND HANDLING a.  For artificial respiration procedures, refer to FM 21 -11 (First Aid for Soldiers). b.  The HWR uses a power supply of 22 - 28 V dc (24 V dc nominal).  Ensure that the power supply is turned off whenever the HWR is not being operated. Use extreme care if performing troubleshooting or maintenance procedures with the power supply connected. c.  The maximum temperature in the HWR is 160 ^OF (71 ^OC) or 190 ^OF (88 ^OC) during normal operation and can reach 205 ^OF (96 ^OC) (Model RAK-15), or 239 ^OF (Model 471012) during overheat conditions before automatic shutdown occurs. Take care to avoid burns if the cover is opened immediately after the HWR has been in operation and be aware that internal heat is retained for long periods when the cover is kept closed.