TM-9-2540-207-14&P Sustainment Manual for A20 Heater for M113 2540-01-396-2826 Download
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TM 9-2540-207-14&P 5-2 5.2 Determining differences between design versions There are three different design versions/iterations of the A20 Vehicular Compartment heater currently in use. This technical manual encompasses all three of those versions. In the case where the procedures in this manual vary from version to version, a separate section will be shown calling attention to the design iteration to which the procedure applies. In general, a particular design iteration can be identified through the serial number of the heater or by the nameplate. For example, design iteration #1 was used in all heaters that have a Global Thermoelectric nameplate. Refer to Table 1 for a list of design iterations and their respective serial number ranges. However, in order to be certain of the design iteration of the A20 being used, refer to the following instructions in order to confirm. Table 1. A20 Design Iterations Design Iteration #1 All heaters with Global Thermoelectric nameplates Design Iteration #2 Hunter Mfg. Co. S/N: 10001 - 21069 Design Iteration #3 Hunter Mfg. Co. S/N: 21070 - Present In order to determine the design version of A20, remove the top control cover by removing the four screws as shown in Figure 5.2-1 A20 Control Cover. Set the cover and screws aside. Figure 5.2-1 A20 Control Cover Once the cover is removed, inspect the control head area and note the following features in order to identify design iterations.