Data processing: generic control systems or specific application – Generic control system – apparatus or process – Plural processors
Reexamination Certificate
1999-04-30
2004-03-23
Grant, William (Department: 2121)
Data processing: generic control systems or specific application
Generic control system, apparatus or process
Plural processors
C700S009000, C062S127000
Reexamination Certificate
active
06711445
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to the field of refrigeration. More specifically, the invention relates to controllers in refrigeration systems. Even more specifically, the invention relates to consolidating, for example, the power connection, control circuit wiring, relays, circuit breakers, switches and indicators of a refrigeration controller into a single unit.
BACKGROUND OF THE INVENTION
Refrigeration systems are used in a variety of circumstances, including refrigerated cases in grocery stores, refrigerated warehouses, air conditioners and other similar systems. In one example of a refrigeration system, illustrated in
FIG. 1
, a rack controller
10
receives signals from sensors
12
distributed around the refrigeration system. The sensors may include temperature sensors, pressure sensors or any other kind of sensor that would be helpful in determining the refrigeration status of the area being refrigerated.
The rack controller
10
includes logic which analyzes the signals received from the sensors
12
along with information stored within the controller and determines whether, for example, the level of refrigeration should be increased or decreased or whether the system should be defrosted. The level of refrigeration being applied and the defrosting function are determined by whether or not an assortment of loads
14
and
16
have been actuated or activated. For example, the loads
14
and
16
may include compressor motors, refrigeration valves and defrost elements. Special switches, called contactors
18
are used to isolate the high power necessary to activate some of the loads
14
, such as the compressor motors, from the rest of the system. Other loads
16
do not require such isolation. In most cases, the wiring to the loads
16
and the contactors
18
is protected by a circuit breakers (or fuses)
20
. Further, power to the loads
16
and contactors
18
can be interrupted by opening switches
21
.
An electronic relay board
22
controls activation of the loads
16
and the contactors
18
. Typically, the electronic relayboard
22
includes one relay for every load
16
and contactor
18
. The rack controller
10
controls the refrigeration system by sending commands to the electronic relay board
22
which causes one of the loads
14
and
16
to actuate or un-actuate.
The system typically includes mechanisms to allow manual control of the loads
14
and
16
. For example, the system may include a set of toggle switches
24
that can be used to override the rack controller
10
and actuate or un-actuate a particular load
14
and
16
. Further, the system typically includes a set of indicator lights
26
, typically one or more for each load
14
and
16
, which illuminate when various events or conditions concerning the loads
14
and
16
occur. For example, the system may include one light that will indicate that a load is actuated. Another light may indicate that control of the load has been overridden by actuation of one of the toggle switches.
Typically, all of the components shown in
FIG. 1
are separate items that are wired and powered separately. For example, the toggle switches
24
, indicators
26
, and switches
21
may be on a door of a rack panel or panels separate from the electronic relay board
22
. At installation, wiring between the switch/indicator rack panel and the electronic relay board
22
is installed. The circuit breakers
20
are typically installed in another panel, which is wired to the electronic relay board
22
upon installation.
SUMMARY OF THE INVENTION
The invention eliminates much of the wiring associated with a refrigeration control system by consolidating in a single module several of the functions of the control system. For example, in one embodiment, the functions of the electronic relay board, the circuit breakers, the toggle switches, the indicator lights, and the power connections for all of the circuits are consolidated into a single module.
In one aspect, the invention features a refrigeration control apparatus comprising a master unit. The master unit includes a mother board, which includes a bus configured to carry signals between boards coupled to the mother board. The master unit further includes a processor board interfaced to the mother board. The processor board comprises a processor, a program memory, and instructions for the processor stored on the program memory. An interface circuit is coupled to the mother board. A load control module is interfaced to the mother board. The load control module comprises an interface circuit coupled to the mother board. A circuit breaker is coupled to a power input. A load relay is coupled to the circuit breaker. The load relay is configured to switch power. An override switch and the processor are coupled to the load relay to control the load relay. An indicator is coupled to the processor and the override switch.
Implementations of the invention may include one or more of the following. The refrigeration control apparatus may include a slave unit coupled to the master unit. The slave unit may comprise a mother board and a load control module. The refrigeration control apparatus may further include a communications circuit coupled to the processor. The communications circuit may comprise a serial communications circuit, a network communications circuit or both. The refrigeration control apparatus may include a rack controller interfaced to the master unit through the communications circuit. The load relay may include a first interlocked relay and a second interlocked relay. Line voltage may be removed from the second interlocked relay when the first interlocked relay is actuated. The override switch may have a first position and a second position. The first interlocked relay may be actuated when the override switch is in the first position and the second interlocked relay may be actuated when the override switch is in the second position. The override switch may have a third position. The first interlocked relay and the second interlocked relay may be under the control of the processor when the override switch is in the third position. The indicator may provide a first indication when the override switch is in the first or second positions. The indicator may provide a second indication when the override switch is in the third position and the first interlocked relay is actuated. The indicator may provide a third indication when the override switch is in the third position and the second interlocked relay is actuated. The load control module may comprise a circuit interface module configured to be coupled to one or more loads. The loads may be one or more selected from the group of a coil on a refrigeration valves and a coil on a defrost contactor. The load control module may comprise a compressor module configured to be coupled to one or more loads comprising a coil on a compressor contactor.
The refrigeration control apparatus may include a fault circuit configured to detect the occurrence of a fault and report it to the processor board. The processor may be configured to illuminate a fault indicator upon the occurrence of the fault. The refrigeration control apparatus may include a fault reset switch coupled to the processor board. The processor may be configured to stop illuminating the fault indicator when the fault reset switch is activated. The refrigeration control apparatus may include a fault circuit configured to detect the occurrence of one or more of a plurality of faults and report the existence of one or more faults and the identity of the one or more faults to the processor board. The processor may be configured to report the identity of the one or more faults to a rack controller.
In general, in another aspect, the invention features a refrigeration control system comprising a rack controller, sensors coupled to the rack controller, a refrigeration control apparatus coupled to the rack controller, and one or more loads coupled to the refrigeration control apparatus.
Implementations of the invention may include one or more of the f
Friedlander Paul
Heath Richard
Pellerin Henry Robert
Rader Roy M.
Baker & Botts L.L.P.
Frank Elliot
Grant William
Kysor/Warren
LandOfFree
Refrigeration control apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refrigeration control apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refrigeration control apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3263614