TM 5-6115-593-34 NAVFAC P-8-631-34 TO-35C2-3-463-2 for    illustration    of    overshoot    and undershoot. (b) Divide  the  result  obtained  in  (a)  by rated    voltage    (as    given    on    the generator nameplate), then multiply by 100 to convert to percentage. CAUTION Do not use the constant operating voltage at each load as the divisor in the computation.  Use only the rated voltage of the generator. (5) To determine the time required to restore stable  voltage  conditions  after  each  load change (recovery time): (a) The prescribed steady-state voltage bandwidth, extended to the point at which  the  voltage  trace  leaves  the prescribed   steadystate   band,   shall be  considered  as  the  time  at  which the transient conditions begin.  The point   at   which   the   voltage   trace enters and remains within the prescribed band after a load change shall  be  considered  as  the  point  at which stabilization begins. (b) Measure the distance (in inches) on the  chart  from  the  point  where  the voltage  trace  leaves  the  prescribed steady-state band to the point where it  re-enters  and  remains  within  the prescribed voltage band for the next load condition. (c) Divide   this   distance   by   the   chart speed (in inches per second).  This will  give  the  voltage  recovery  time, in seconds. (6) Determine   the   voltage   regulation   for   all load  changes  (for  example,  rated  load  to no  load,  1/2  rated  load  to  no  load  to  1/4 load, etc.) as follows: (a) Using the indicating voltmeter readings  subtract  the  load  value  of voltage  from  the  no  load  value  for each load change (for example step (a)    to    step    (b)).        (For    voltage regulators utilizing single-phase voltage sensing, the value of voltage   in   the   sensed   phase   only shall be used in the above calculations.  For voltage regulators utilizing multiphase sensing the average value of the sensed voltage shall be used.) (b) Convert each of the values obtained (1)  above  to  a  percentage  of  rated voltage   by   dividing   by   the   rated voltage    and    multiplying    by    100. This is the voltage regulation expressed in percent. (c) Repeat  paragraph  16-15d(1)  above substituting frequency for voltage. (d) Compare   the   results   tabulated   in paragraphs         16-15d(1)         and 16-15d(6)(c)  with  the  requirements of table 16-1. 16-16.  FREQUENCY ADJUSTMENT RANGE TEST. a. General.  It is necessary that the frequency of a generator   set   be   adjustable   to   provide   rated frequency at various load conditions as required in certain applications and to synchronize two or more generator sets for parallel operation. b. Apparatus.    Instrumentation  for  measuring  load conditions,     field     voltage     and     current,     and ambient  temperature  shall  be  as  described  and illustrated in MIL-HDBK-705. 16-12