TM 1-1510-224-10 (b) OFF.        Removes    power    from    the CHALS, lowband, and remaining mission equipment. WARNING When     the     GRFA     transmit     (XMIT) mode    is    selected    the    GRFA    will transmit RF energy, regardless of the position   of   the   WOW   switch.      The position    of    the    WOW    switch    only determines   the   level   of   power   that will be radiated by the GRFA. (11) Weight-on-wheels    override    switch.        The weight-on-wheels    override    switch    is    placarded    WOW OVERRIDE    ON    OFF.        A    weight-on-wheels    sensor provides  an  indication  to  the  Guardrail  Radio  Frequency Assembly (GRFA) of whether the aircraft is on the ground (WOW active) or airborne (WOW inactive).  When   WOW is   active,   modes   which   would   cause   RF   energy   to   be radiated  by  the  GRFA  are  physically  reduced  to  radiate RF energy at the low power level when  TRANSMIT mode is selected through the MFD. (a) ON.  Overrides the  WOW  sensor and allows   the   operator   to   transmit   RF   energy   at   the   high power level while the aircraft is on the ground. (b) OFF.    Turns  off  the  override  function of     the     WOW     sensor, preventing the GRFA from transmitting  RF  energy  at  the  high  power  level  while  the aircraft is on the ground. (12) Three-phase  AC  bus  cross  tie  switch.    The three-phase  AC  bus  cross  tie  switch,  placarded   3f  AC CONTROL  BUS  CROSS  TIE  ON/AUTO  OFF,   controls the AC bus cross tie. (a) ON/AUTO.  In the ON/AUTO position the   AC   busses   will   automatically   be   connected   if   an inverter fails. (b) OFF.      In   the   OFF   position   the   AC busses will not be connected (no cross-tie). (13) Three-phase  AC  inverter  control  switches. Two  three-phase  AC  inverter  control  switches,  placarded 3f  AC  CONTROL  #  1  and  #  2  INV  RESET  ON  OFF, control operation of the three-phase inverters. (a) RESET.    When  an  inverter  is  off-line  due either  to  a  fault  or  to  placing  the  inverter  switch  to  the OFF   position,   the   affected   unit   cannot   have   its   output restored  until  the  inverter  switch  is  moved  to  the  spring loaded RESET ON position. (b) ON.        ON    position    selects    inverter operation. (c) OFF.  OFF position turns off inverter. (14) Three-phase    AC    external    power    switch. The   three-phase   AC   external   power   switch,   placarded 3fAC   CONTROL   EXT   PWR   -   RESET   -   ON   -   OFF, controls  application  of  external  three-phase  AC  power  to the aircraft. (a) RESET.        The    AC    external    power switch   must   be   moved   to   the   spring   loaded    RESET position,  then  to  the   ON   position   to   bring   AC   external power on line. (b) ON.  ON position applies AC external power to the three-phase busses through the AC external power receptacle under the left wing. (c) OFF.        OFF    position    removes    AC external power from the three-phase busses. (15) Three-phase  AC  meter  switch.    The  three phase  meters  switch,  placarded   METERS  Af  -   Bf  -   Cf controls which phase of the three-phase inverters is being measured by the AC voltage, frequency, and loadmeters. (16) ASE    control    switch.        The    ASE    control switch,   placarded   ASE   SILENT   NORM   OFF,   controls operation of the ASE. (a) SILENT.  When the   SILENT  position is   selected,   the   transmitting   elements   of   the   ASE   are placed in a passive mode. (b) NORM.    The   NORM  position  allows normal ASE operation. (c) OFF.      The    OFF    position    removes power   from   ASE   equipment.      When   the    ASE   control switch is set back to  NORM, the originally selected mode will again become active. 4-2