John Gilmer wrote:


The 2005 NEC requires AFCIs with series AND parallel protection starting
1-1-2008. I don't know of any on the market now.


Sounds like the AFCI folks sold the NEC a bill of goods!




From http://www.cpsc.gov/volstd/afci/AFCIFireTechnology.pdf

As part of the U.S. Consumer Product Safety Commission's (CPSC's) 1994
and 1995 efforts to reduce residential electrical system fires, the CPSC
sponsored work on detecting and monitoring conditions that could lead to
or cause fires in homes. The work was performed by Underwriters
Laboratories Inc. (UL) and was documented in a report entitled,
"Technology for Detecting and Monitoring Conditions that Could Cause
Electrical Wiring System Fires." The study uncovered several possible
technologies and concluded that arc-fault detection combined with
ground-fault protection was the most promising technology to reduce the
risk of fire when combined with conventional circuit breakers. At that
time, such an arc-fault circuit breaker did not exist as a commercial
device. Additional research has led to the development of the AFCI as a
commercial product.
-------------------
Series arcs, protection for which is being added to AFCIs, include loose
connections. The current is limited by the load current downstream from
the arc, so they won't trip breakers. They can, however, generate a lot
of heat.

The NEC is a pretty pragmatic code. Changes usually require a
demonstration that the change will improve safety.

Bud--