Re: GFCI Problem
A few facts:
Ground Fault Circuit Interrupters (GFCIs) are listed under the Product Category KCXS are covered by Standard for Safety UL 943. Those GFCIs manufacturered on or after January 1, 2003 meet (although there were some recalls announced on/about August 2003 - December 2003) the newer revisions to the certification requirements added to that Standard which include: a more stringent voltage surge immunity test, newer corrosion tests to demonstrate greater immunity to moist conditions, an operating test to verify that proper operation of the GFCI cannot be prevented by manipulation of the GFCI conditions, a reverse line-load miswire test that requies the GFCI to deny power to feed-through when reverse wired (it may still power the face), an abnormal overvoltage test that requires the GFCI not become a fire or shock hazard in extreme overvoltage conditions, demonstrated immunity to conducted disturbances induced by radio-frequency (RF) fields, and supplemental voltage surge tests to assure GFCIs provide maximum protection against unwanted consequences of transient voltage surges. GFCIs manufactured on or after July 28, 2006 meet the newest revisions to the Standard for Safety certification requirements regarding end of life tests and revised miswiring tests (including denying power to the face as well as feed-through power).
Products manufactured prior to those dates were and are allowed to remain in the marketplace/stock and be sold even though they do not meet the newer and newest standards. Manufacturer's production date codes located on the device itself or its packaging can be verified with the manufacturer to determine the date of manufacture. Although coming across older stock inventory is not uncommon anywhere in the supply chain in the lower 48, I recall seeing some very old items still offered for sale during a trip to Alaska when I visited a few years ago, and suspect it might be your experience as well.
GFCIs activate when leakage current reaches 4.0 - 6.0 mA.
UL 250, the Stanard for Safety for Household Refrigerators and Freezers, specifically limits the maximum permitted leakage current to 0.75 mA during the defrost cycle, which is well below the trip point for a functioning and installed GFCI. A properly working refrigerator or freezer will NOT be responsible for tripping a modern functioning and properly installed GFCI.
On a side note, UL categorizes sump pumps under the product category "Pumps, Electrically Operated, Liquid (REUZ)" and are certified under the Standard for Safety for Motor Operated Water Pumps, UL 778, which likewise permits a MAXIMUM leakage current of 0.75 mA, and therefore if operating properly, will not be responsible for tripping a modern functioning and properly installed GFCI.
If you have a newer or newest GFCI (breaker or receptacle), I would first suspect a fault condition (damage or corrosion to wiring, inproper installation, etc., a failed or damaged component of the appliance; or operation of the appliance in conditions (past or present) other than those recommended by the manufacturer and contrary to its listing. This could include moisture, ambient temperatures which drop below 40 degrees F, losening of a case ground, damage to the power cord or plug, and a host of others. If your GFCI is older or its age of manufacture cannot be verified, I would first swap it out with one that was manufactured on/after August 2006.
Something as simple as a damp area, subject to condensation or higher (especially as temps cool in the evening) humidity and the lack of a weather resistant receptacle (noted by a "WR" on the face) on a GFCI protected circuit can collect enough moisture on the faceplate of the receptacle to cause a trip.
Following a cycle (blower directing warm moist air at the receptacle location then cooling significantly and condensation when the blower stops) in cooler temps can collect enough liquid water to cause a trip due to an actual fault condition.
If the GFCI protection is from a breaker - you also need to consider that the reason for the trip may be other than ground fault.
I noticed in your other post string the mention of some wiring circa 1975, and recall the supply chain to most of Alaska was in the order of 6-12 months or more in the early and mid-70s. Therefore wonder if you may have aluminum wiring in your circuits, especially of a pre-72 or so, even less safe than a later produced aluminum alloy. I also note there has been other recent electrical work described on your earlier post (which was slightly unclear in your discussion of two circuits) consider the possibility of multi-wire branch circuits or a wiring error in your previous efforts possibly including an equipment ground or incomplete or incorrect bond.
Last edited by Gray Watson; 09-15-2009 at 10:44 AM.
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