Section 279. Fire alarm signal systems and fire drills

1. Fire alarm signal
  systems.  Except as may otherwise be provided by the board in its rules,
  every factory building over two stories in height  in  which  more  than
  twenty-five  persons  are  employed  above  the  ground  floor  shall be
  equipped by the owner thereof with a fire alarm signal system  having  a
  sufficient  number  of  signals  clearly audible to all occupants of the
  building, and so arranged as to permit the sounding of  all  the  alarms
  within  the  building  whenever  the  alarm  is  sounded  in any portion
  thereof. Such system shall be maintained in good working  order  and  no
  person  shall tamper with same or render ineffective any portion thereof
  except to repair it. A person discovering a fire shall cause an alarm to
  be sounded immediately. The board of standards and appeals in  the  city
  of  New  York  and  elsewhere  the  board may make rules and regulations
  relating to the installation of fire alarm signals and  prescribing  the
  number,  character  and  location  of  the  signals  and  the method and
  character of the  installation  including  that  of  all  appliances  in
  connection therewith.
    2.  Fire  drills.  Except as may otherwise be provided by the board in
  its rules, in every factory building over two stories in height in which
  more than twenty-five persons are employed above  the  ground  floor,  a
  fire  drill shall be conducted at least once a month in which all of the
  occupants of the building shall  participate  simultaneously  and  which
  shall  conduct all such occupants to a place of safety. In New York city
  the  fire  commissioner  and  elsewhere  the  board  shall  make  rules,
  regulations  and  special orders necessary or suitable to each situation
  and to secure the personal  co-operation  of  all  the  tenants  of  the
  building  in  a  fire  drill  of  all the occupants thereof. Such rules,
  regulations and orders may  require  the  posting  of  the  same  or  an
  abstract  thereof  and  may  prescribe  upon whom shall rest the duty of
  carrying them out.
    3. Exceptions. Subdivisions one and two  of  this  section  shall  not
  apply  to a building in which every square foot of the floor area on all
  stories is protected with  an  automatic  sprinkler  system  having  two
  adequate  sources of water supply and approved by the public authorities
  having jurisdiction thereof and in which  also  the  maximum  number  of
  occupants of any one floor does not exceed by more than fifty per centum
  the capacity of the exits, as determined by subdivisions one, two, three
  and  four  of section two hundred and seventy-eight. If the commissioner
  after investigation determines  that  the  spirit  of  this  chapter  is
  observed  and  public  safety  secured  he  may  permit  in place of the
  automatic sprinkler  system  before  specified  an  automatic  sprinkler
  system  having  one  adequate source of water supply and approved by the
  public authorities having jurisdiction thereof.
    4. The provisions of this section shall be enforced in the city of New
  York by the  fire  commissioner  of  said  city  and  elsewhere  by  the
  commissioner.