Fused electrical safety barrier for protection of an electrical load placed in a potentially hazardous location
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 7, 1991
Grant Date -
N/A
app pub date -
Aug 31, 1989
filing date -
Sep 21, 1988
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
To protect an encapsulated fuse (9) within a wholly enclosed sealed safety barrier having a first voltage limiting circuit (10) and a current limiting circuit (15), an externally accessible high current interrupter (5), such as a fuse, positive temperature coefficient resistor (26) or circuit breaker (27) is connected in series with an input terminal, and further serially connected with a second voltage limiting circuit (6) connected downstream of the interrupter and across the safety barrier circuit, the second voltage limiting circuit having a voltage limiting response characteristic which is, preferably, the same as the first voltage limiting circuit within the barrier, and the interrupter having a response threshold which is at least as high, but may be higher than the fuse (9) encapsulated within the circuit. The combination of the second voltage limiting circuit (6) with the fuse (5) acts as a clamping circuit, in case of over-voltage or other malfunction, with respect to the encapsulated fuse (9) so that the externally accessible interrupting element can be replaced or reset, or will reset automatically to avoid replacement of the entire safety barrier.
First Claim
Other Claims data not available