Situation: I was having combination arc fault circuit interrupters (CAFCI) installed in some 20 Amp and 15A branch circuits. In several cases , the CAFCI immediately tripped after installation, or tripped when an appliance was started. Devices were installed by licensed professional electrician.
Load center is Square D, Type QOC 30UF, Series S01, Type 1 enclosure. Single family residence.
The offending circuits are: 1. Branch circuit (20A) feeding a furnace induced draft blower motor (12 Amp full load). No other devices in circuit. CAFCI is Square D, QO120CAFIC (pigtail neutral) Device tripped immediately on installation and CB set to ON.
Branch circuit (20A) feeding kitchen, with a refrigerator, convenience receptacles, and some CFL lighting. CAFCI is Square D, QO120CAFIC (pigtail neutral) Device tripped immediately on installation and CB set to ON.
Branch circuit (20A) feeding kitchen dish washer and a disposal (Insinkerator). CAFCI trips when disposal is started. CAFCI is Square D, QO120CAFIC (pigtail neutral)
I have had no tripping problems on these circuits with the standard 20A 1-Pole CBs installed.
Q1: Will a AFCI cause the same incompatibility problem as the CAFCI?
Q2: Are CAFCI (and perhaps AFCIs) not compatible with circuits supplying appliance or HVAC motors? (is this a series arcing problem?)
NOTE: I have square D QO dual—function (CAFCI+GFCI) and CAFCI CBs installed on other branch circuits (20A & 15A) that include ceiling fans, range hood blower, microwave, desktop computers (fans), and a tankless gas water heater. These CBs do not trip when fans are started or the water heater gas ignition operates.