Sec.  15.107   Conducted limits.

   

   (a) Except for Class A digital devices, for equipment that is designed
   to be connected to the public utility (AC) power line, the radio
   frequency voltage that is conducted back onto the AC power line on any
   frequency or frequencies within the band 150 kHz to 30 MHz shall not
   exceed the limits in the following table, as measured using a 50 µH/50
   ohms line impedance stabilization network (LISN). Compliance with the
   provisions of this paragraph shall be based on the measurement of the
   radio frequency voltage between each power line and ground at the
   power terminal. The lower limit applies at the band edges.

------------------------------------------------------------------------
                                          Conducted limit (dBmV)
  Frequency of emission (MHz)   ----------------------------------------
                                      Quasi-peak            Average
------------------------------------------------------------------------
0.15-0.5.......................  66 to 56*..........  56 to 46*
0.5-5..........................  56.................  46
5-30...........................  60.................  50
------------------------------------------------------------------------
*Decreases with the logarithm of the frequency.

   (b) For a Class A digital device that is designed to be connected to
   the public utility (AC) power line, the radio frequency voltage that
   is conducted back onto the AC power line on any frequency or
   frequencies within the band 150 kHz to 30 MHz shall not exceed the
   limits in the following table, as measured using a 50 µH/50 ohms LISN.
   Compliance with the provisions of this paragraph shall be based on the
   measurement of the radio frequency voltage between each power line and
   ground at the power terminal. The lower limit applies at the boundary
   between the frequency ranges.

------------------------------------------------------------------------
                                          Conducted limit (dBmV)
  Frequency of emission (MHz)   ----------------------------------------
                                      Quasi-peak            Average
------------------------------------------------------------------------
0.15-0.5.......................  79.................  66
0.5-30.........................  73.................  60
------------------------------------------------------------------------

   (c) The limits shown in paragraphs (a) and (b) of this section shall
   not apply to carrier current systems operating as unintentional
   radiators on frequencies below 30 MHz. In lieu thereof, these carrier
   current systems shall be subject to the following standards:

   (1) For carrier current systems containing their fundamental emission
   within the frequency band 535-1705 kHz and intended to be received
   using a standard AM broadcast receiver: no limit on conducted
   emissions.

   (2) For all other carrier current systems: 1000 µV within the
   frequency band 535-1705 kHz, as measured using a 50 µH/50 ohms LISN.

   (3) Carrier current systems operating below 30 MHz are also subject to
   the radiated emission limits in Sec. 15.109(e).

   (d) Measurements to demonstrate compliance with the conducted limits
   are not required for devices which only employ battery power for
   operation and which do not operate from the AC power lines or contain
   provisions for operation while connected to the AC power lines.
   Devices that include, or make provision for, the use of battery
   chargers which permit operating while charging, AC adaptors or battery
   eliminators or that connect to the AC power lines indirectly,
   obtaining their power through another device which is connected to the
   AC power lines, shall be tested to demonstrate compliance with the
   conducted limits.

   [ 54 FR 17714 , Apr. 25, 1989, as amended at  57 FR 33448 , July 29, 1992;
    58 FR 51249 , Oct. 1, 1993;  66 FR 19098 , Apr. 13, 2001;  67 FR 45670 ,
   July 10, 2002]