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US 11,108,223 B2Granted
Abnormal impedance fault isolation
AssigneeJohnson Controls Fire Protection LP
InventorsAlexandre Gouin, Sébastien Choquette
Life of this patent
Estimating the term…
Abstract
In an aspect, a fire detection system is described. The first detection system may include isolation circuit having an isolation switch coupled with a system line of the fire detection system and configured to isolate a first side of the system line from a second side of the system line. The isolation circuit may also include a controller coupled with the isolation switch. The controller may be configured to detect a short circuit on the system line and control the isolation switch based on a calculated impedance on the system line in response to detecting the short circuit.
Claims16
An isolation circuit of a fire detection system, comprising:
- an isolation switch coupled with a system line of the fire detection system and configured to isolate a first side of the system line from a second side of the system line;
- a current monitor coupled with the system line configured to measure a current level on the system line;
- a voltage monitor coupled with the first side of the system line and the second side of the system line, and configured to measure a voltage level on the system line, the voltage monitor being different from the current monitor;
- and
- a controller coupled with the isolation switch, the current monitor, and the voltage monitor and configured to:
- detect a short circuit on the system line;
- determine whether the short circuit occurred on the first side of the system line or the second side of the system line;
- receive a current level signal representing the current level on the system line from the current monitor and a voltage level signal representing the voltage level on the system line from the voltage monitor, in response to detecting the short circuit on the first side of the system line;
- determine whether the short circuit on the first side of the system line is false or not based on a current threshold being satisfied by the current level signal and a voltage threshold being satisfied by the voltage level signal;
- control the isolation switch to open or to remain opened to isolate the first side of the system line from the second side of the system line in response to one of the current threshold or the voltage threshold not being satisfied;
- and
- control the isolation switch to close or to remain closed to not isolate the first side of the system line from the second side of the system line in response to the current threshold and the voltage threshold being satisfied.
9 more elements
A method for zone isolation by a controller of an isolation circuit of a fire detection system, comprising:
- detecting a short circuit on a system line of the fire detection system;
- determining whether the short circuit occurred on a first side of the system line or a second side of the system line;
- receiving a current level signal representing a current level on the system line from a current monitor of the isolation circuit coupled with the system line and a voltage level signal representing a voltage level on the system line from a voltage monitor of the isolation circuit coupled with the system line, in response to detecting the short circuit on the first side of the system line;
- determining whether the short circuit on the first side of the system line is false or not based on a current threshold being satisfied by the current level signal and a voltage threshold being satisfied by the voltage level signal;
- controlling an isolation switch of the isolation circuit coupled with the system line to open or to remain opened to isolate the first side of the system line from the second side of the system line in response to one of the current threshold or the voltage threshold not being satisfied;
- and
- controlling the isolation switch to close or to remain closed to not isolate the first side of the system line from the second side of the system line in response to the current threshold and the voltage threshold being satisfied.
4 more elements
A computer-readable medium storing computer executable code for zone isolation by a controller of an isolation circuit of a fire detection system, comprising code to:
- detect a short circuit on a system line of the fire detection system;
- determine whether the short circuit occurred on a first side of the system line or a second side of the system line;
- receive a current level signal representing a current level on the system line from a current monitor of the isolation circuit coupled with the system line and a voltage level signal representing a voltage level on the system line from a voltage monitor of the isolation circuit coupled with the system line, in response to detecting the short circuit on the first side of the system line;
- determine whether the short circuit on the first side of the system line is false or not based on a current threshold being satisfied by the current level signal and a voltage threshold being satisfied by the voltage level signal;
- control an isolation switch of the isolation circuit coupled with the system line to open or to remain opened to isolate the first side of the system line from the second side of the system line in response to one of the current threshold or the voltage threshold not being satisfied;
- and
- control the isolation switch to close or to remain closed to not isolate the first side of the system line from the second side of the system line in response to the current threshold and the voltage threshold being satisfied.
4 more elements
Dependencies are inferred from the claim text.