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.
   Frequency of emission (MHz) Conducted limit (dBμV)
                               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.
   Frequency of emission (MHz) Conducted limit (dBμV)
                               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]