Multiple heater control system with expandable modular functionality

Heater control apparatus, comprising a set of components that are configured for assembly in a variety of desired combinations of daisy chain connected heater control systems for a plurality of heaters, including:

• A. A plurality of heater controller base modules, each of which includes a base module housing containing (i) an AC power circuit extending between an inlet connector and an outlet connector in the base module housing, (ii) a controllable high-limit power switch and a process power switch in the AC power circuit, (iii) a high-limit control circuit that controls the high-limit power switch to turn the AC power circuit on and off to the outlet connector in response to a comparison of a temperature measurement from a first temperature sensor to a preset high-temperature parameter and a power sequence that includes a power off and on sequence, and (iv) a process control circuit that controls the process power switch to turn the AC power circuit on and off to the outlet connector in response to a comparison of a temperature measurement from a second temperature sensor to a preset operating set point temperature;
• B. A plurality of controller expansion modules, each of which includes an expansion module housing that is physically attachable to the base module and contains (i) a tactile data input interface, (ii) a visual alpha-numeric display, (iii) an adjust/display microprocessor, and (iv) a data connection interface with the base module for user input of adjustments of the high-limit parameter and the operating temperature set point and for display of the high-limit parameter and the operating temperature set point;
• C. A plurality of heaters, each of which comprises (i) an AC powered heating element for producing heat, (ii) a first temperature sensor positioned in close enough proximity to the heating element to sense heat produced by the heating element, (iii) a second temperature sensor positioned in close enough proximity to the heating element to sense heat produced by the heating element, and (iv) a heater inlet connector that is connected electrically to the heating element and to the first and second temperature sensors and which is physically and electrically for mating connection to the outlet connector of the heater controller for routing controlled AC power from the AC power circuit in the heater controller to the heating element of the heater and for routing sensed temperature signals from the first and second temperature sensors to the heater controller;
• D. A plurality of T-type source power cables, each of which comprises (i) a trunk section and a branch section, (ii) a trunk inlet connector and a trunk outlet connector on opposite ends of the trunk section, (iii) a branch outlet connector on the branch section that is configured physically and electrically for mating connection to the inlet connector of the heater controller for routing AC source power into the heater controller, and (iv) a pair of trunk AC power conductors that extend between and connect the trunk inlet connector electrically to the trunk outlet connector, and wherein said branch outlet connector being connected electrically in parallel to the trunk AC power conductors, wherein the trunk inlet connector and the trunk outlet connector are configured physically and electrically for mating connection with each other so that the trunk sections of the plurality of T-type source power cables can be daisy chain connected together in order to provide AC source power from an AC power source to the plurality of heater controllers;
• E. At least one linear-type terminating source power cable with an inlet connector and a terminal outlet connector on opposite ends of the linear-type terminating source power cable and a pair of AC power conductors extending between and electrically connecting the inlet connector and the terminal outlet connector, wherein the inlet connector of the linear-type terminating source power cable is configured physically and electrically for mating connection to the trunk outlet connector of the T-type source power cable and the terminal outlet connector of the linear-type terminating source power cable is configured physically and electrically for mating connection with the inlet connector of the heater controller for routing the AC source power to the heater controller;
• F. A slave adapter comprising (i) a master segment that includes a master inlet connector, which is configured physically and electrically for mating connection with the outlet connector of the heater controller for routing controlled AC power from the heater controller to the slave adapter and for routing temperature signals from the first and second temperature sensors to the heater controller, a master outlet connector, which is configured physically and electrically for mating connection with the heater inlet connector for routing controlled AC power from the slave adapter to a master heater and for routing temperature signals from the first and temperature sensors to the slave adapter, a pair of master AC power conductors that extend between and electrically connect the master inlet connector to the master outlet connector to conduct controlled AC power from the master inlet connector to the master outlet connector, two pairs of low voltage signal conductors that extend between and electrically connect the master inlet connector and the master outlet connector for routing temperature signals from the first and second temperature sensors from the master outlet connector to the master inlet connector, and (ii) a slave segment that includes a slave outlet connector and a pair of slave AC power conductors that connect the slave outlet connector electrically in parallel to the master AC power conductors;
• and
• G. A plurality of T-type slave power cables, each of which includes:
• (i) slave trunk section, (ii) a slave branch section, (iii) a slave trunk inlet connector on one end of the slave trunk section that is configured physically and electrically to mate with the slave outlet connector of the slave adapter, (iv) a slave trunk outlet connector on the other end of the slave trunk section that is configured physically and electrically the same as the slave outlet connector of the slave adapter to accommodate daisy chain connection of a plurality of T-type slave power cables, (v) a pair of slave trunk AC power conductors that extend between and electrically connect the slave trunk inlet connector to the slave trunk outlet connector to route controlled AC power from the slave trunk inlet connector to the slave trunk outlet connector, and (vi) a slave branch outlet connector that is connected electrically in parallel to the slave trunk AC power conductors and is configured physically and electrically to mate with the heater inlet connectors to route controlled AC power to the slave heaters.

A method of controlling a plurality of heaters that are powered by AC power from an AC power source to produce heat, comprising:

• positioning a heater controller adjacent each of the plurality of heaters, with each heater controller having means for turning AC power in an AC power circuit on and off based on comparison of a sensed heater temperature to an operating temperature set point to create AC controlled power, wherein each heater has an inlet connector for receiving AC source power into the AC power circuit and an outlet connector for delivering controlled AC power to the heaters;
• connecting the heaters electrically to the respective heater controllers via the outlet connectors of the heater controllers so that the heaters are powered by the controlled AC power;
• and
• connecting the AC power from the AC power source to the plurality of heater controllers via a series of T-type source power cable sections, each of which has a trunk segment that is daisy chain connected to the trunk segment of another one of the T-type source power cables and each of which has a branch segment that connects to one of the heater controllers via the inlet connector of the heater controller so that the heater controllers are connected electrically in parallel in relation to each other in the AC power circuit.

A method of controlling a plurality of heaters that are powered by AC power from an AC power source, comprising:

• positioning a heater controller adjacent a plurality of heaters, each of which has a heating element and at least one temperature sensor adjacent the heating element and a heater inlet connector where power wires connected electrically to the heating element and signal wires connected electrically to the temperature sensor are terminated, wherein the heater controller includes an inlet connector for receiving AC power from the AC power source, an outlet connector for receiving temperature signals from the temperature sensor in the heater and for delivering controlled AC power to the heating element in the heater, and a process control circuit that compares the temperature signals to at least one temperature set point parameter and turning the AC power to the heater on and off based on the comparison of the temperature signal to the set point parameter;
• operating one of the heaters as a master heater by connecting both the signal wires and the power wires at the heater inlet connector to the controller outlet connector via respective power and signal conductors in a slave adapter;
• and
• operating at least one more of the plurality of heaters as a slave heater by connecting only the power wires at the heater inlet connector of that heater to the controller outlet connector via power conductors in the slave adapter that connect the heaters electrically in parallel to the AC power.

A method of controlling a heater that has an AC powered heating element and that has at least one temperature sensor, comprising:

• connecting a heater controller base module electrically to an AC power source and connecting the heating element and the temperature sensor of the heater electrically to the heater controller base module;
• comparing temperature signals from the temperature sensor to a temperature set point parameter in the base module and switching the AC power to the heater on and off in the base module to provide controlled AC power to the heater based on the comparison of the signals from the temperature sensor to the temperature set point parameter;
• and
• displaying the sensed temperature and the set point parameter by attaching a detachable expansion module to the base module, wherein the expansion module has display apparatus and a microprocessor that is programmed to receive sensed temperature and set point data from the base module and to process aid sensed temperature and set point data for display at the expansion module.