초록 ▼

A probe is mounted on a water submersible pump or other fluid handling device housed within a vault for a transformer, elevator or the like. The probe will extend into any water which accumulates in the bottom of the vault enabling a conductive path to be established through an appropriate electric

A probe is mounted on a water submersible pump or other fluid handling device housed within a vault for a transformer, elevator or the like. The probe will extend into any water which accumulates in the bottom of the vault enabling a conductive path to be established through an appropriate electric circuit to the pump motor to permit operation of the pump for pumping water from the vault. Oily fluids, which are immiscible in the water and will normally rise to a level above the water level in the vault, will come in contact with the probe to render the probe nonconductive, thereby inactivating the pump circuit. An alarm is provided to indicate the presence of oil in the vault. In order to prevent false alarms when the probe is nonconductive due to immersion in air, a controller is provided to inhibit operation of the alarm unless a float is raised and the probe is nonconductive.

대표청구항 ▼

[What is claimed is:] [1.]a float that indicates whether air in the housing has been displaced by a predetermined level of at least one of the conductive and non-conductive liquids that have accumulated in the housing;a conductivity probe positionable at a probe level that is below the predetermined

[What is claimed is:] [1.]a float that indicates whether air in the housing has been displaced by a predetermined level of at least one of the conductive and non-conductive liquids that have accumulated in the housing;a conductivity probe positionable at a probe level that is below the predetermined level, for detecting whether the conductive liquid is present at the probe level;wherein an intake of the pump is positioned below the probe level; andmeans for triggering an alarm when the float indicates that at least one of the liquids is present at the predetermined level, and the conductivity probe does not detect the presence of the conductive liquid at the probe level, thereby indicating that the non-conductive liquid is present in the housing, at least between the probe level and the predetermined level.