Electric field shielding system for AC electrically powered device with a two-blade plug

摘要

An electric field shield for non-grounded AC powered appliances is connected to a neutral return terminal of the AC power distribution system. A polarized two prong connector assures connection of the shield to neutral. By eliminating a requirement for connection of the shield to ground, shields are made available for appliances precluded from ground connection such as bedding heaters. A double pole control switch is included to eliminate E-field generation in an OFF state caused by improper wiring or the use of unpolarized intermediate connectors. The shield is insulated and a current limiting device is series connected between the shield and neutral to reduce electrical hazards.