SUDDEN PRESSURE RELAY HAVING SEISMIC PROTECTION

摘要

A relay which measures sudden increases in the pressure of gas located above the fluid dielectric in electrical apparatus. The relay includes defeating apparatus which prevents the operation of the sudden pressure relay when the sudden increase in gas pressure is caused by abrupt changes in the fluid level due to physical disturbances outside the apparatus enclosure. One arrangement includes a switch which is activated, when a float on the surface of the dielectric fluid is raised sufficiently, to prevent energization of the sudden pressure relay. Another arrangement uses two sudden pressure relays which are located at diagonally opposite corners of the apparatus tank and are serially connected so that both relays must be activated at the same time to energize the associated control or alarm circuits. Other arrangements use baffles and multiple opening tubes to prevent false activation of the sudden pressure relay by keeping the fluid away from the gas opening of the sudden pressure relay.