Microprocessor based controller for heating system
First Claim
1. An integrated primary, safety and limit control device for a building heating system, said system including a heat exchanger having a combustion side and a fluid side in which a fluid is heated, a gas or oil fired fuel burner coupled to said combustion side for heating said fluid when said fuel is ignited, heat radiating means coupled to said heat exchanger, circulating means for transporting said fluid between said heat exchanger and said heat rediating means, adjustable thermostat means for establishing a desired temperature within said building, first sensor means for providing a signal indicative of heat exchanger fluid side temperature, second sensor means for providing a signal indicative of outdoor temperature, said device comprising, limit control means for establishing high and low temperature limits for said system, lockout means for selectively disabling said burner and said circulating means in response to a lockout signal, temperature sensing means responsive to said first and second sensor means for providing control signals indicative of outdoor temperature and fluid side temperature and for providing control signals indicative of a failure of said first sensor means, microprocessor means responsive to said temperature sensing means, said thermostat means and said limit control means for providing said lockout signal in response to said control signal indicative of a failure of said first sensor means and for providing signals to said burner and said circulating means for controlling the operation thereof, whereupon said fluid side temperature is modulated by the operation of said burner as a function of said fluid side temperature and outdoor temperature and said circulating means is enabled to operate whether or not said burner is ignited as a function of said fluid side temperature and outdoor temperature to attain the indoor temperature as established by said thermostatic means, said microprocessor being responsive to said limit control means for disabling said burner to prevent fuel ignition if said fluid side temperature would exceed said high temperature limit and for enabling burner ignition when called upon to do so if the fluid side temperature drops below said low temperature limit.
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Accused Products
Abstract
An integrated, microprocessor-based primary control system for a building heating system. The control system includes in one unit a microprocessor and associated circuitry for (1) establishing the high limit of heat exchanger operation, (2) establishing the low-limit of heat exchanger operation for systems having a summer/winter coil, (3) modulating heat exchanger temperature as a function of outdoor temperature, (4) detecting alarm conditions, providing audio-visual signals while locking out heat exchanger operation in response thereto, and (5) providing an override time period for domestic hot water production in systems having a summer/winter coil.
59 Citations
14 Claims
- 1. An integrated primary, safety and limit control device for a building heating system, said system including a heat exchanger having a combustion side and a fluid side in which a fluid is heated, a gas or oil fired fuel burner coupled to said combustion side for heating said fluid when said fuel is ignited, heat radiating means coupled to said heat exchanger, circulating means for transporting said fluid between said heat exchanger and said heat rediating means, adjustable thermostat means for establishing a desired temperature within said building, first sensor means for providing a signal indicative of heat exchanger fluid side temperature, second sensor means for providing a signal indicative of outdoor temperature, said device comprising, limit control means for establishing high and low temperature limits for said system, lockout means for selectively disabling said burner and said circulating means in response to a lockout signal, temperature sensing means responsive to said first and second sensor means for providing control signals indicative of outdoor temperature and fluid side temperature and for providing control signals indicative of a failure of said first sensor means, microprocessor means responsive to said temperature sensing means, said thermostat means and said limit control means for providing said lockout signal in response to said control signal indicative of a failure of said first sensor means and for providing signals to said burner and said circulating means for controlling the operation thereof, whereupon said fluid side temperature is modulated by the operation of said burner as a function of said fluid side temperature and outdoor temperature and said circulating means is enabled to operate whether or not said burner is ignited as a function of said fluid side temperature and outdoor temperature to attain the indoor temperature as established by said thermostatic means, said microprocessor being responsive to said limit control means for disabling said burner to prevent fuel ignition if said fluid side temperature would exceed said high temperature limit and for enabling burner ignition when called upon to do so if the fluid side temperature drops below said low temperature limit.
- 13. An integrated primary, safety limit and control device for a building heating system, said system including a heat exchanger having a combustion side and a fluid side in which a fluid is heated, a gas or oil fired fuel burner coupled to said combustion side for heating said fuel when said fuel is ignited, heat radiating means coupled to said heat exchanger, circulating means for transporting said fluid between said heat exchanger and said heat radiating means, first means for providing a signal indicative of outdoor temperature, second means for providing a signal indicative of heat exchanger fluid side temperature, and third means for providing a signal indicative of desired temperature within said building, said device comprising microprocessor means, heat exchanger and outdoor sense circuit means, limit decode and select means, and lockout circuit means, said limit decode and select circuit means providing high and low temperature limit control signals and decode signals, said high and low temperature limit control signals being coupled to said heat exchanger and outdoor sense circuit means, said decode signals being coupled to said microprocessor means, said heat exchanger and outdoor sense circuit means being coupled to said first and second means for providing control signals indicative of outdoor temperature and heat exchanger fluid side temperature in response to the signals provided by said first and second means and for providing control signals indicative of a failure of said second means, said control signals being coupled to said microprocessor means under the control of said decode signals from said limit decode and select circuit means, said microprocessor means being coupled to said third means for receipt of the signal indicative of desired temperature within said building, said microprocessor means providing first output signals coupled to said heat exchanger burner, second output signals coupled to said circulating means, and a lockout signal coupled to said lockout circuit means in the event of a failure of said second means, irrespective of whether or not said failure results in an open or closed circuit signal produced by said second means, said lockout circuit means for selectively disabling said burner and said circulating means in response to said lockout signal, whereupon if said burner and said circulating means are not disabled by said lockout means, said microprocessor means effects the modulation of said fluid side temperature by the operation of said burner as a function of said fluid side temperature and outdoor temperature and wherein said circulating means is enabled to operate whether or not said burner is ignited as a function of said fluid side temperature and outdoor temperature to attain the indoor temperature as established by said third means, said microprocessor operating in response to said decode signals and said control signals for disabling said burner to prevent fuel ignition if said fluid side temperature would exceed a maximum limit as established by said limit decode and select means and for enabling burner ignition if the fluid side temperature drops below a predetermined threshold temperature.
Specification