Abstract: A method that includes obtaining a sensor reading from a sensor installed inside an underground vault and determining whether the sensor reading is indicative of an alarm state. When the sensor reading is indicative of the alarm state, the method obtains at least one new reading and determines whether the sensor reading includes sensor drift based at least in part on the at least one new reading. The alarm state is established when the sensor reading is determined not to include sensor drift. The sensor drift is removed when the sensor reading is determined to include sensor drift.

Abstract: A hose for use with a blower and an underground vault. The hose surviving an explosion initiated inside the underground vault. The hose is blast-resistant, arc-flash-resistant, and fire-resistant. A first end of the hose is connectable to the blower and configured to receive fresh air from the blower when connected thereto. The hose conducts the fresh air to a second end of the hose. The second end is positionable inside the underground vault wherein the fresh air provides sufficient breathable air to any personnel present in the underground vault.

Abstract: A tank including a fluid reservoir, a communication module, a controller, and at least one sensor. The fluid reservoir is configured to be in fluid communication with a cable segment. The communication module is configured to communicate with an external device. The sensor is configured to detect an injection parameter value, encode the injection parameter value in a sensor signal, and send the sensor signal to the controller. The controller is configured to automatically instruct the communication module to transmit information to the external device based on the injection parameter value.

Abstract: A tank including a fluid reservoir, a communication module, a controller, and at least one sensor. The fluid reservoir is configured to be in fluid communication with a cable segment. The communication module is configured to communicate with an external device. The sensor is configured to detect an injection parameter value, encode the injection parameter value in a sensor signal, and send the sensor signal to the controller. The controller is configured to automatically instruct the communication module to transmit information to the external device based on the injection parameter value.

Abstract: A method that includes obtaining a sensor reading from a sensor installed inside an underground vault and determining whether the sensor reading is indicative of an alarm state. When the sensor reading is indicative of the alarm state, the method obtains at least one new reading and determines whether the sensor reading includes sensor drift based at least in part on the at least one new reading. The alarm state is established when the sensor reading is determined not to include sensor drift. The sensor drift is removed when the sensor reading is determined to include sensor drift.

Abstract: A method that includes obtaining a sensor reading from a sensor installed inside an underground vault and determining whether the sensor reading is indicative of an alarm state. When the sensor reading is indicative of the alarm state, the method obtains at least one new reading and determines whether the sensor reading includes sensor drift based at least in part on the at least one new reading. The alarm state is established when the sensor reading is determined not to include sensor drift. The sensor drift is removed when the sensor reading is determined to include sensor drift.

Abstract: A system that includes a gas sensor, a fresh air flow controller, a sample flow controller, and a system controller. The fresh air flow controller is configured to deliver fresh air to the gas sensor. The sample flow controller is configured to deliver a sample to the gas sensor. The system controller has a processor connected to memory storing instructions that are executable by the processor. When executed, the instructions cause the processor to determine an intermix ratio of the sample to the fresh air, instruct the fresh air flow controller and the sample flow controller to deliver the fresh air and the sample, respectively, to the gas sensor in accordance with the intermix ratio, and receive a sensor reading from the gas sensor after the fresh air flow controller and the sample flow controller have adjusted the fresh air and the sample, respectively.

Abstract: A method configured to be executed by a system controller. The method includes obtaining a first metric from a first sensor installed in a first underground vault of a system of interconnected underground vaults, and obtaining a second metric from a second sensor installed in a second underground vault of the system. The first and second underground vaults are in fluid communication with one another via one or more connections. The method also includes locating a gas source based at least in part on one or both of the first and second metrics, and performing an action. The action includes identifying the gas source to one or more users and/or altering a rate of atmospheric turnover in at least a portion of the system.

Abstract: A method performed by a system controller and evaluating a manhole event occurring in a duct-manhole system. The method includes estimating a size of the manhole event occurring in the system or estimating relative contributions to a fire of at least two of oxidative decomposition, pyrolysis, plasmatization, and flammable gas accumulation. Optionally, the method may include notifying one or more users and/or altering a rate of atmospheric turnover in the duct-manhole system.

Abstract: A system including an active ventilation device and a system controller. The active ventilation device is installed in an underground vault and generates an exhaust flow from the vault having an exhaust rate. The system controller is configured to determine that a reading received from a selected gas sensor indicates that a manhole event is occurring, and instruct the active ventilation device to change the exhaust rate when the reading indicates that the manhole event is occurring. The system controller is configured to receive at least one sensor reading after the exhaust rate has been changed, determine whether the selected gas sensor is exhibiting drift based at least in part on the sensor reading(s), and perform an action when the system controller determines the selected gas sensor is not exhibiting drift. The action includes notifying a user and/or instructing the active ventilation device to alter the exhaust rate.

Abstract: A method performed by a system controller and estimating a size of a manhole event occurring in a network of manhole vaults interconnected by connections. The method includes obtaining first, second, and third mass flow rates for each of a plurality of gaseous components present in exhaust, fresh air, and event flows, respectively, and estimating the size based on the third mass flow rate obtained for at least one of the gaseous components. The exhaust flow exits a selected vault of the manhole vaults, the fresh air flow enters the selected vault from an external atmosphere, and the event flow originates from the manhole event. The third mass flow rate for each of a portion of the gaseous components is determined by subtracting the second mass flow rate obtained for the gaseous component from the first mass flow rate obtained for the gaseous component.

Abstract: A system for use with a connection comprising a terminus opening into an underground vault. The system includes a perturbation detector and a system controller. The perturbation detector is configured to detect values of each of one or more properties and transmit a signal encoding the values to the system controller. The system controller is configured to receive the signal, use at least one of the values to determine whether a fire is occurring or has occurred, and alert a user when the system controller determines that the fire is occurring or has occurred.

Abstract: A flow restrictor for installation in a connection having a terminus opening into an underground vault. The flow restrictor includes an annular restriction device and a concentration member. The annular restriction device is configured to be installed in the annulus near the terminus opening and to restrict a flow of one or more gases through the annulus of the connection. The concentration member is configured to concentrate the flow and includes a through-channel configured to allow the concentrated flow to flow between the underground vault and the annulus.

Abstract: A tank including a fluid reservoir, a communication module, a controller, and at least one sensor. The fluid reservoir is configured to be in fluid communication with a cable segment. The communication module is configured to communicate with an external device. The sensor is configured to detect an injection parameter value, encode the injection parameter value in a sensor signal, and send the sensor signal to the controller. The controller is configured to automatically instruct the communication module to transmit information to the external device based on the injection parameter value.

Abstract: A tank including a fluid reservoir, a communication module, a controller, and at least one sensor. The fluid reservoir is configured to be in fluid communication with a cable segment. The communication module is configured to communicate with an external device. The sensor is configured to detect an injection parameter value, encode the injection parameter value in a sensor signal, and send the sensor signal to the controller. The controller is configured to automatically instruct the communication module to transmit information to the external device based on the injection parameter value.

Abstract: A flow restrictor for installation in a connection having a terminus opening into an underground vault. The flow restrictor includes an annular restriction device and a concentration member. The annular restriction device is configured to be installed in the annulus near the terminus opening and to restrict a flow of one or more gases through the annulus of the connection. The concentration member is configured to concentrate the flow and includes a through-channel configured to allow the concentrated flow to flow between the underground vault and the annulus.

Abstract: A hose for use with a blower and an underground vault. The hose surviving an explosion initiated inside the underground vault. The hose is blast-resistant, arc-flash-resistant, and fire-resistant. A first end of the hose is connectable to the blower and configured to receive fresh air from the blower when connected thereto. The hose conducts the fresh air to a second end of the hose. The second end is positionable inside the underground vault wherein the fresh air provides sufficient breathable air to any personnel present in the underground vault.

Abstract: A system for use with a connection comprising a terminus opening into an underground vault. The system includes a perturbation detector and a system controller. The perturbation detector is configured to detect values of each of one or more properties and transmit a signal encoding the values to the system controller. The system controller is configured to receive the signal, use at least one of the values to determine whether a fire is occurring or has occurred, and alert a user when the system controller determines that the fire is occurring or has occurred.

Abstract: A method performed by a system controller and evaluating a manhole event occurring in a duct-manhole system. The method includes estimating a size of the manhole event occurring in the system or estimating relative contributions to a fire of at least two of oxidative decomposition, pyrolysis, plasmatization, and flammable gas accumulation. Optionally, the method may include notifying one or more users and/or altering a rate of atmospheric turnover in the duct-manhole system.

Abstract: A method performed by a system controller and estimating a size of a manhole event occurring in a network of manhole vaults interconnected by connections. The method includes obtaining first, second, and third mass flow rates for each of a plurality of gaseous components present in exhaust, fresh air, and event flows, respectively, and estimating the size based on the third mass flow rate obtained for at least one of the gaseous components. The exhaust flow exits a selected vault of the manhole vaults, the fresh air flow enters the selected vault from an external atmosphere, and the event flow originates from the manhole event. The third mass flow rate for each of a portion of the gaseous components is determined by subtracting the second mass flow rate obtained for the gaseous component from the first mass flow rate obtained for the gaseous component.