Bad ground and reverse polarity detection for HVAC controls
First Claim
1. An HVAC control comprising:
- a digital input configured to receive a digital signal;
an analog input configured to receive an analog signal; and
an error indicator;
the HVAC control configured to receive a neutral signal at the analog input, measure a voltage of the neutral signal with respect to earth ground, to operate the error indicator to provide a first indicator status indicative of a normal state if the measured voltage is below a first voltage threshold, to operate the error indicator to provide a second indicator status indicative of a bad ground state if the measured voltage is between the first voltage threshold and a second voltage threshold, and to operate the error indicator to provide a third indicator status indicative of a reverse polarity state if the measured voltage is above the second voltage threshold;
wherein the first voltage threshold and the second voltage threshold are different, and wherein the first indicator status, the second indicator status and the third indicator status are different.
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Accused Products
Abstract
In exemplary embodiments, HVAC controls and corresponding error detection methods are disclosed. In an exemplary embodiment, an HVAC control generally includes a digital input configured to receive a digital signal, an analog input configured to receive an analog signal, and an error indicator. The control is configured to receive a neutral signal at the analog input, determine a voltage of the neutral signal with respect to earth ground, and operate the error indicator to indicate a normal state if the voltage is below a first threshold, a bad ground state if the voltage is between the first threshold and a second threshold, and a reverse polarity state if the voltage is above the second threshold.
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Citations
20 Claims
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1. An HVAC control comprising:
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a digital input configured to receive a digital signal; an analog input configured to receive an analog signal; and an error indicator; the HVAC control configured to receive a neutral signal at the analog input, measure a voltage of the neutral signal with respect to earth ground, to operate the error indicator to provide a first indicator status indicative of a normal state if the measured voltage is below a first voltage threshold, to operate the error indicator to provide a second indicator status indicative of a bad ground state if the measured voltage is between the first voltage threshold and a second voltage threshold, and to operate the error indicator to provide a third indicator status indicative of a reverse polarity state if the measured voltage is above the second voltage threshold; wherein the first voltage threshold and the second voltage threshold are different, and wherein the first indicator status, the second indicator status and the third indicator status are different. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An HVAC control comprising:
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a digital input configured to receive a digital signal; an analog input configured to receive an analog signal; an error indicator; the HVAC control configured to receive a neutral signal at the analog input, measure a voltage of the neutral signal, to operate the error indicator to provide a first indicator status indicative of a normal state if the measured voltage is below a first voltage threshold, to operate the error indicator to provide a second indicator status indicative of a bad ground state if the measured voltage is between the first voltage threshold and a second voltage threshold, and to operate the error indicator to provide a third indicator status indicative of a reverse polarity state if the measured voltage is above the second voltage threshold; and a resistor divider circuit coupled to the analog input, the resistor divider circuit configured to receive the neutral signal and scale the neutral signal voltage to a voltage level capable of being safely read by the analog input; wherein the first voltage threshold and the second voltage threshold are different, and wherein the first indicator status, the second indicator status and the third indicator status are different. - View Dependent Claims (12, 13, 14)
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15. A method of HVAC control error detection, the method comprising:
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receiving a neutral signal at an analog input of an HVAC control; measuring a voltage of the neutral signal; and providing a first indication status of a normal state if the voltage is below a first voltage threshold, providing a second indication status of a bad ground state if the voltage is between the first voltage threshold and a second voltage threshold, and providing a third indication status of a reverse polarity state if the voltage is above the second voltage threshold; wherein the first voltage threshold and the second voltage threshold are different, and wherein the first indication status, the second indication status and the third indication status are different. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification