NotTaR of Television Sets : GFCI tripping with TV, monitor, or other..  
 Copyright © 1994-2007, Samuel M. Goldwasser. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied: 1. This notice is included in its entirety at the beginning. 2. There is no charge except to cover the costs of copying. I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.

         << Comments on lightning dam.. |  Index  | Multisystem TVs >>

GFCI tripping with TV, monitor, or other high tech equipment

Ground Fault Circuit Interrupters (GFCIs) are very important for minimizing shock hazards in kitchens, bathrooms, outdoors and other potentially wet areas. They are now generally required by the NEC Code in these locations. However, what the GFCI detects to protect people - an imbalance in the currents in the Hot and Neutral wires caused possibly by someone touching a live conductor - may exist safely by design in high tech electronic equipment. The result - false tripping - is mostly a problem with 3 wire grounded devices with built in line filters having capacitors between Hot and Ground but may also occur with 2 wire ungrounded TVs due to the power-on surge into the highly capacitive or inductive loads of their power supplies.

However, it's also possible for this to happen when a TV is hooked to a cable system because it's cable shield is connected to Earth ground. In such a case, this may or may not be a cause for concern.

TVs using Hot chassis designs couple the antenna and its cable shield to the tuner with small coupling capacitors. A side effect is that some AC leakage current can flow through these capacitors, possibly enough to trip the GFCI. If the TV's plug isn't polarized, try reversing it and see if the problem goes away. If it is polarized, make sure your outlet is wired properly and you aren't using a non-polarized extension cord with the TV plugged reversed.

It's also possible the TV is faulty and the tripping is actually taking place as a result of a legitimate problem.

To assure the set is safe, (whether reversing the plug helps or not), a leakage test should really be performed by measuring the AC current between the TV's antenna shield and an Earth ground. Try it with both polarities of the wall plug. Anything over about 8 mA will trip a GFCI. If the leakage current is less than this with either polarity of the wall plug, the GFCI is overly sensitive. If the leakage current is much more with either polarity of the wall plug, the set is defective and should be serviced immediately. It should not be used until the problem is corrected as a serious shock hazard exists.

 <<Comments on lightning dam.. | ToC | Multisystem TVs>>