Patent Grant
10544962
The invention relates to electric water heaters.
In one embodiment, the invention provides a storage-type water heater including a tank for supporting water to be heated; a first heating bank including a first heating surface disposed within the tank; a first contactor connected to the first heating bank; a second heating bank including a second heating surface disposed within the tank; a second contactor connected to the second heating bank; and a controller for selectively operating the first contactor and the second contactor, the controller including instructions for, in one power cycle, operating the first contactor to supply power to the first heating bank, and while supplying power to the first heating bank, operating the second contactor to supply power to the second heating bank.
In another embodiment, the invention provides a method for operating a storage-type water heater including a first heating bank including a first heating surface disposed within the tank, a first contactor connected to the first heating bank, a second heating bank including a second heating surface disposed within the tank, a second contactor connected to the second heating bank, and a controller for selectively operating the first contactor and the second contactor, the method comprising: operating the first contactor to supply power to the first heating bank; thereafter operating the second contactor to supply power to the second heating bank; thereafter operating one of the first contactor and the second contactor to stop supply power to the corresponding heating bank; and thereafter operating the other of the first contactor and the second contactor to stop supply power to the corresponding heating bank.
In another embodiment, the invention provides a storage-type water heater including a tank for supporting water to be heated; a first heating bank including a first heating surface disposed within the tank; a first contactor connected to the first heating bank; a second heating bank including a second heating surface disposed within the tank; a second contactor connected to the second heating bank; and a controller for selectively operating the first contactor and the second contactor, the controller including instructions for operating one of the first contactor and the second contactor to stop supply power to the corresponding heating bank, and operating the other of the first contactor and the second contactor to stop supply power to the corresponding heating bank.
In another embodiment, the invention provides a storage-type water heater including a tank for supporting water to be heated; a first heating bank including a first heating surface disposed within the tank; a first contactor connected to the first heating bank; a second heating bank including a second heating surface disposed within the tank; a second contactor connected to the second heating bank; a temperature probe disposed within the tank for generating a signal having a relation to the temperature of the water in the tank; and a controller for selectively operating the first contactor and the second contactor based on the signal, the controller including instructions for, in a first sequence, operating the first contactor to supply power to the first heating bank as a result of the value of the signal being less than a first threshold value, and operating the second contactor to supply power to the second heating bank as a result of the value of the signal being less than a second threshold value, the first threshold value being greater than the second threshold value, and, in a second sequence, operating one of the first contactor and the second contactor to stop supply power to the corresponding heating bank as a result of the value of the signal being greater than a third threshold value, and operating the other of the first contactor and the second contactor to stop supply power to the corresponding heating bank as a result of the value of the signal being greater than a fourth threshold value, the fourth threshold value being greater than the third threshold value.
In another embodiment, the invention provides a storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first relay and the second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, based on the selected mode.
In another embodiment, the invention provides a method for operating a water heater, the method comprising receiving, at a controller, a selection between at least one selected from the group consisting of a no-sequencing mode, wherein a first relay and a second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially, and operating, via the controller, the first relay to supply power to a first heating element, and operating the second relay to supply power to a second heating element, basing the operation on the selected mode.
In another embodiment, the invention provides a storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first and second relays are operated to supply power to the first and second heating elements concurrently, a linear sequencing mode, wherein in one heating cycle, the first relay is operated to supply power to the first heating element, while operating the first relay the second relay is operated to supply power to the second heating element, then while supplying power to the second heating element operating the first relay to stop supply power to the first heating element while power is still supplied to the second heating element, and a progressive sequencing mode, wherein in one heating cycle, the first relay is operated to supply power to the first heating element, while operating the first relay the second relay is operated to supply power to the second heating element, then while supplying power to the first heating element operating the second relay to stop supply power to the second heating element while power is still supplied to the first heating element. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, basing the operation on the selected mode.
A storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, a temperature probe disposed within the tank for generating a signal having a relation to the temperature of the water in the tank, and a controller for selectively operating the first relay and the second relay based on the signal. The controller includes instructions for selecting an operation based on at least the following modes, a no-sequencing mode, wherein the first and second relays are operated to supply power to the first and second heating elements concurrently, a linear sequencing mode, wherein, in one heating cycle, the first relay to supply power to the first heating element as a result of the value of the signal being less than a first threshold value, the second relay to supply power to the second heating element as a result of the value of the signal being less than a second threshold value, the first threshold value being greater than the second threshold value, the first relay stopping supply power to the first heating element as a result of the value of the signal being greater than a third threshold value, and the second relay stopping supply power to the second heating element as a result of the value of the signal being greater than a fourth threshold value, the fourth threshold value being greater than the third threshold value, and a progressive sequencing mode, wherein, in one heating cycle, the first relay to supply power to the first heating element as a result of the value of the signal being less than a first threshold value, the second relay to supply power to the second heating element as a result of the value of the signal being less than a second threshold value, the first threshold value being greater than the second threshold value, the second relay stopping supply power to the second heating element as a result of the value of the signal being greater than a third threshold value, and the first relay stopping supply power to the first heating element as a result of the value of the signal being greater than a fourth threshold value, the fourth threshold value being greater than the third threshold value. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, basing the operation on the selected mode.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
In the illustrated construction, the control box 35 is mounted on a side wall 45 of the outer shell 15. The control box 35 includes a door 50 and encloses a central control board (CCB) 55, power circuitry 60, a number of fuses 65, and a number of contactors 70. A user interface module (UIM) 75 is mounted on the door 50 of the control box 35. However, in other constructions, the UIM 75 can also be enclosed within the control box 35. The control box 35 also provides access to a temperature probe 80 and a number of heating elements 85 mounted on the wall of the tank 20. Particularly, the control box 35 encloses an access portion 90 of the water heater 10 including a wall 95 extending between the outer shell 15 and the tank 20. Among other things, the access portion 90 provides access to a portion of the water tank 20 to install, maintain, and operate elements mounted on the tank 20. Such elements include, but are not limited to, the temperature probe 80 and heating elements 85.
As further explain below, the CCB 55 is utilized to control the contactors 70 that, in turn, relay power from the power circuitry 60 to the heating elements 85. Particularly, the CCB 55 controls the contactors 70 based upon, among other things, a signal from the temperature probe 80. The fuses 65 are connected between the power circuitry 60 and the contactors 70 to regulate the power supply to the contactors 70 and heating elements 85. Further, a user or manufacturer can program, customize settings, and operate the water heater 10 via the UIM 75.
As illustrated in
The heating elements 85 are mounted on the tank 20 forming three heating banks 100, 105, and 110. Each heating bank 100, 105, and 110 includes three heating elements 85. More specifically, heating elements 85a, 85b, and 85c form the first heating bank 100, heating elements 85d, 85e, and 85f form the second heating bank 105, and heating elements 85g, 85h, and 85i form the third heating bank 110. As further explained below, power is supplied to the heating elements 85 of each heating bank 100, 105, and 110 simultaneously. In the illustrated construction, each heating bank 100, 105, and 110 is characterized by the heating elements 85 being arranged diagonally with respect to one another. Further, the second heating bank 105 is above the first heating bank 100, and the third heating bank 110 is above the second heating bank 105 with respect to the axis 42. Other constructions of the water heater 10 can include a different number and/or a different arrangement of heating elements 85.
In the illustrated construction, the water heater 10 is operable to receive power, via terminal block 120 of the power circuitry 60, from a single-phase electrical source or a three-phase electrical source. Based on the electrical source for providing power to the water heater 10, the terminal block 120 is configured or connected as a single-phase block 125 or a three-phase block 130. It is to be understood that the single-phase block 125 and the three-phase block 130 illustrated in
For ease of description, the following refers specifically to the wiring configuration of the first heating bank 100. As illustrated in
The temperature probe 80 is directly connected to the CCB 55 to deliver a signal related to the temperature of the water in the tank 20. Further, the temperature probe 80 is associated with an energy cut off (ECO) switch (not shown) operable to help prevent water in the tank 20 from overheating. As further explained below with respect to the operation of the water heater 10, the ECO switch opens when the temperature probe 80 senses a temperature above a predetermined safe value. As a result, the CCB 55 controls the contactors 70 to interrupt current to the heating elements 85 and instructs the UIM 75 to display a fault message. Other constructions of the water heater 10 can include other sensors, probes, or sensing mechanisms connected to the CCB 55 for operating the water heater 10.
Although not shown, each of the element sensors 155 is connected to or is operable to detect the current through one corresponding heating element 85. As illustrated in
The UIM 75 includes a display system 180 for displaying messages, warnings, fault indicators, settings, and other information related to the operation of the water heater 10 and the CCB 55. The UIM 75 also includes other interface devices, such as buttons and/or dials 185, which in combination with the display system 180, allow a user or manufacturer to access and configure the CCB 55 for operating the water heater 10. For example, the CCB 55 can include, among other things, a controller with a memory (not shown) including settings and instructions for operating the water heater 10. The settings and instructions are accessible via the UIM 75 or other suitable means, such as a programming interface of the CCB 55 (not shown).
In the illustrated construction, the CCB 55 includes adjustable settings that allow the CCB 55 to operate the water heater 10 as shown in
During manufacturing or installation of the water heater 10, a user or manufacturer can individually select the parameters and settings of the water heater 10 in the CCB 55 via the UIM 75. In some constructions, the CCB 55 can also include in memory a list of water heater model numbers, each model number being associated with a number of parameters and settings of a specific water heater. For example, a model number of the water heater 10 can be associated with parameters indicating, among other things, the water heater 10 including three heating banks, each heating bank having three heating elements. Accordingly, a user or manufacturer can simply select the model number, via the UMI 75, instead of selecting all the water heater parameters and settings individually.
With specific reference to the temperature settings or thresholds, such temperature settings allow operation of the water heater 10 based on the signal provided by the temperature probe 80 (shown in
The set point temperature is a value provided as primary reference for the CCB to operate the water heater 10. In other words, the set point temperature helps determine or calculate the temperature of the water at which the CCB 55 selectively controls the contactors 70 to either relay or stop power to the corresponding heating elements 85. In one example, for a temperature set point of about 120° F./49° C., the CCB 55 can be operable to initiate heating of the water in the tank 20 when the temperature of the water is equal or less than the temperature set point minus a temperature differential, as further explained below. Similarly, the CCB 55 can be operable to stop heating of the water (i.e., operate contactor(s) 70 to stop power supply to the corresponding heating bank 100, 105, 110) when the temperature of the water is equal to the set point temperature. Based on the application of the water heater 10, the temperature set point can be reprogrammed by a user or manufacturer to be a value between about 90° F. and 194° F. In other constructions, the CCB 55 can include instructions to reprogram the set point temperature to a value within a different range of temperatures.
The bank temperature differential is a value designated to each heating bank 100, 105, and 110 for calculating a temperature of the water in the tank 20 at which each heating bank (e.g., heating banks 100, 105, and 110) is operated. More specifically, the set point temperature and the bank temperature differential of each heating bank 100, 105, and 110 are used to determine at which temperature the contactor 70 of each heating bank 100, 105, and 110 starts or stops relaying power to the corresponding heating bank 100, 105, and 110. In the illustrated construction, the temperature differential can be a value between about 1° F. and 20° F. However, in other constructions the CCB 55 can include instructions to reprogram the temperature differential to a value within a different range of temperatures.
The operating settings, such as sequencing modes and bank rotation, refer to the mode of operation of the contactors 70 and corresponding heating banks 100, 105, and 110. In the illustrated construction, the CCB 55 can include instructions to operate the heating banks 100, 105, and 110 based on three heating sequences: no sequencing, linear sequencing and progressive sequencing. In other constructions of the water heater 10, the CCB 55 can include instructions to operate the heating banks 100, 105 and 110 according to other heating sequences.
When operating the heating banks with the no-sequencing heating sequence, all heating banks (e.g., heating banks 100, 105 and 110) are energized concurrently to heat the water in the tank 20 during a heating cycle, and all heating banks are dienergized concurrently. For practicality purposes, there is a relatively small time delay (e.g., one second delay) when energizing the heating banks 100, 105, and 110, for reducing starting current requirements. When operating the heating banks with linear sequencing or progressive sequencing, in a heating cycle, the heating banks are energized sequentially based on the water temperate as calculated in the following formula:
where TSETPOINT is the set point temperature (e.g., 120° F.), # is the heating bank number (e.g., 1, 2 and 3 for heating banks 100, 105, and 110, respectively), and Ti_DIFF is the temperature differential for each heating bank (e.g., T1_DIFF=3, T2_DIFF=3 and T3_DIFF=3).
Linear sequencing provides for the heating banks to be de-energized in a First-On-Last-Off sequence. The following formula particularly describes the sequence for de-energizing the heating banks 100, 105, and 110:
while progressive sequencing provides for the heating banks to be de-energized in a First-On-First-Off sequence.
Further, when a user or manufacturer enables bank rotation during the manufacturing or installation of the water heater 10, heating banks 100, 105, and 110 are rotated during subsequent heating cycles to help ensure substantially equal or analogous use of the heating elements 85 of the heating banks 100, 105, and 110. For example, heating cycles of the water heater 10 operating the heating banks 100, 105, and 110 with linear sequencing and enabled bank rotation are as follows.
In another example, heating cycles of the water heater 10 operating the heating banks 100, 105 and 110 with progressive sequencing and enabled bank rotation are as follows.
If the temperature of the water in the tank 20 is below the value determined in step 205, the CCB 55 proceeds to a heating mode (Step 215) for heating the water in the tank 20. Particularly, the heating mode at step 215 is characterized by the CCB 55 operating the contactors 70 and heating banks 100, 105, and 110 to heat water in the tank 20 as described above with respect to the heating sequences. The water heater 10 remains in the heating mode at step 215 until the CCB 55 determines that water in the tank 20 has reached a temperature substantially equal or above the temperature set point. When the temperature of the water in the tank 20 is substantially equal or above the set point temperature, the CCB 55 proceeds to the stand-by mode 210.
In addition to the heating mode (at step 215) and the stand-by mode (at step 210), the CCB 55 can also operate the water heater 10 in a fault mode. More specifically, the CCB 55 can proceed to the fault mode at any instant during the operation of the water heater 10 as a result of the CCB 55 detecting a fault condition. For example, the temperature probe 80 detecting a temperature of the water in the tank 20 at or above the ECO safe temperature constitutes a fault condition. As a result of the fault condition, the ECO switch is actuated causing the CCB 55 to operate the contactors 70 to stop current to the heating banks 100, 105, and 110 and the UIM 75 to display a fault message (e.g., a message showing the temperature of the water in the tank 20). In the illustrated construction, to operate the water heater 10 subsequent to the fault state, the fault condition needs to subside and a user needs to manually reset or restart the water heater 10. In some cases, however, to operate the water heater 10 subsequent to the fault state, it may be sufficient for the fault condition to subside.
The CCB 55 is also operable to detect warning events generated by sensing mechanisms of the water heater 10. In the illustrated construction, the element sensor 155 detects the current flow through one corresponding heating element 85. If the element sensor 155 does not detect a current flow through the heating element 85, the CCB 55 operates the UIM 75 to display a warning message. For example, the UIM 75 may display a message indicating the heating element(s) 85 appear to be inactive. Unlike fault conditions, warning events do not cause the CCB 55 to stop operation of the water heater 10.
As illustrated in
Various features and advantages of the invention are set forth in the following claims.
This application is a continuation of and claims priority to U.S. patent application Ser. No. 12/338,355 entitled “WATER HEATER AND METHOD OF OPERATING THE SAME” filed Dec. 18, 2008, the entire contents of which are incorporated by reference.
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| Number | Date | Country | |
|---|---|---|---|
| 20160348944 A1 | Dec 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12338355 | Dec 2008 | US |
| Child | 15233327 | US |
