Figure 1–1. Typical Terminal Board Connections

TM 1-1520-238-T-4 1–4 1–4 ELECTRICAL DATA (cont) 1–4 (3) Terminal board connections may be illustrated horizontally, vertically, or a combination of both. D C B A E F G SEPARATE TERMINALS A, B, C AND D ARE ELECTRICALLY ISOLATED. LINE INDICATES SEPARATION BETWEEN BLOCKS OF TERMINALS. TERMINALS E AND F ARE INTERNALLY COMMON. TERMINALS G AND H ARE INTERNALLY COMMON. E AND F ARE ISOLATED FROM G AND H. TERMINALS I, J, K AND L ARE COMMON. THERE IS NO ISOLATION BETWEEN THESE TERMINALS. A, B, C AND D ARE COMMON. HORIZONTAL VERTICAL A, B, C AND D ARE COMMON. H I J K L A B C D B A C D COMBINATION M58-179 Figure 1–1. Typical Terminal Board Connections n. Highway Use (fig. 1–2): The alpha character identifies a specific line, and the number in parenthesis identifies the sheet number where the signal terminates. J1 P1 g 1 HIGHWAY NUMBER SHEET NUMBER ALPHA CHARACTER M58-278 A(2) Figure 1–2. Typical Highway Use o. Markings. Markings on equipment and displays are shown in BOLDFACE in text. p. Lamp Indicators. When using lamp indicators for troubleshooting, lamp indicators must be known to be working. q. Forward and Aft Views. Forward (fwd) and aft views refer to fwd and aft in the helicopter. Where required for clarity, FWD and AFT arrows are used.