U.S. patent application number 11/369926 was filed with the patent office on 2007-09-13 for method and systems for operating compressors and fan coils using electronically commutated motors.
This patent application is currently assigned to Regal-Beloit Corporation. Invention is credited to William A. Archer, Brian L. Beifus, Kamron Mark Wright.
Application Number | 20070209377 11/369926 |
Document ID | / |
Family ID | 38477567 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070209377 |
Kind Code |
A1 |
Beifus; Brian L. ; et
al. |
September 13, 2007 |
Method and systems for operating compressors and fan coils using
electronically commutated motors
Abstract
A heating, ventilation, and air conditioning (HVAC) system is
described that includes a first unit and a second unit. The first
unit comprises a controller configured to output a coded compressor
activation signal that is based at least partially on a compressor
run signal received from a thermostat. The second unit comprises at
least a compressor relay. The second unit is configured to receive
and decode the coded compressor activation signal from the first
unit and is operable to operate the compressor relay based on the
decoded content of the coded compressor activation signal.
Inventors: |
Beifus; Brian L.; (Ft.
Wayne, IN) ; Archer; William A.; (Ft. Wayne, IN)
; Wright; Kamron Mark; (Ft. Wayne, IN) |
Correspondence
Address: |
PATRICK W. RASCHE;ARMSTRONG TEASDALE LLP
ONE METROPOLITAN SQUARE, SUITE 2600
ST. LOUIS
MO
63102-2740
US
|
Assignee: |
Regal-Beloit Corporation
|
Family ID: |
38477567 |
Appl. No.: |
11/369926 |
Filed: |
March 7, 2006 |
Current U.S.
Class: |
62/178 ;
62/228.1 |
Current CPC
Class: |
F24F 11/54 20180101;
F24F 11/30 20180101; F24F 1/0003 20130101 |
Class at
Publication: |
062/178 ;
062/228.1 |
International
Class: |
F25D 17/00 20060101
F25D017/00; F25B 49/00 20060101 F25B049/00; F25B 1/00 20060101
F25B001/00 |
Claims
1. A heating, ventilation, and air conditioning system comprising:
a first unit comprising a controller configured to output a coded
compressor activation signal, the coded compressor signal based at
least partially on a compressor run signal received from a
thermostat; and a second unit comprising at least a compressor
relay, said second unit configured to receive and decode the coded
compressor activation signal from said first unit, said second unit
operable to operate said compressor relay based on the decoded
content of the coded compressor activation signal.
2. A heating, ventilation, and air conditioning system according to
claim 1 wherein said first unit comprises a high frequency
generator arid said second unit comprises a high pass filter and a
detector receiving an output of said high pass filter, said first
unit configured to combine a compressor run signal received from a
thermostat with the high frequency for output as the coded
compressor activation signal.
3. A heating, ventilation, and air conditioning system according to
claim 2 wherein said first unit comprises a blower motor, said high
frequency generator integrated into a controller of said blower
motor.
4. A heating, ventilation, and air conditioning system according to
claim 3 wherein said blower motor comprises an electronically
commutated motor.
5. A heating, ventilation, and air conditioning system according to
claim 2 wherein said second unit comprises a compressor relay, an
output of said detector operable to control operation of said
compressor relay.
6. A heating, ventilation, and air conditioning system according to
claim 1 wherein said first unit comprises a blower motor, and
wherein to provide a coded compressor activation signal, said first
unit configured to combine a compressor run signal received from a
thermostat with an identifying signal output by said blower
motor.
7. A heating, ventilation, and air conditioning system according to
claim 6 wherein the compressor run signal and the identifying
signal are combined using a resistor.
8. A heating, ventilation, and air conditioning system according to
claim 7 wherein the compressor activation signal is near ground
potential when the output of said blower motor in a low impedance
state and at an approximate 24 VAC potential when the output of
said blower motor is in a high impedance state.
9. A heating, ventilation, and air conditioning system according to
claim 1 wherein said second unit comprising at least a plurality of
compressor relays, each said relay operable to for activating a
different stage of a compressor, said second unit configured to
receive and decode the coded compressor activation signal from said
first unit, said second unit operable to activate an appropriate
one of said compressor relays based on the decoded content of the
coded compressor activation signal.
10. A method for controlling operation of a compressor within a
heating, ventilation, and air conditioning system, said method
comprising: providing a compressor run signal to a first unit;
utilizing the compressor run signal within the first unit to
generate a coded compressor activation signal; outputting the coded
compressor activation signal to a second unit that includes a
compressor; and decoding the coded compressor activation signal
within the second unit to determine whether the compressor is to be
activated.
11. A method according to claim 10 providing a compressor run
signal to a first unit comprises utilizing a thermostat to output a
compressor run signal.
12. A method according to claim 10 wherein utilizing the compressor
run signal within the first unit to generate a coded compressor
activation signal comprises combining the compressor run signal
with a high frequency signal for output as the coded compressor
activation signal.
13. A method according to claim 12 further comprising integrating a
high frequency generator into a controller of a blower motor within
the first unit.
14. A method according to claim 12 wherein decoding the coded
compressor activation signal within the second unit comprises: high
pass filtering the coded compressor activation signal; applying a
result of the high pass filtering to a detector; and controlling
operation of the compressor based on an output of the detector.
15. A method according to claim 10 wherein utilizing the compressor
run signal within the first unit to generate a coded compressor
activation signal comprises combining a compressor run signal
received from a thermostat with an identifying signal output by a
blower motor within the first unit.
16. A method according to claim 15 wherein combining the compressor
run signal with an identifying signal output comprises combining
the compressor run signal and the identifying signal utilizing a
resistor.
17. A method according to claim 15 wherein combining the compressor
run signal with an identifying signal output comprises: outputting
a coded compressor activation signal at an approximate ground
potential when the identifying signal is in a low impedance state;
and outputting a coded compressor activation signal at an
approximate 24 VAC potential when the identifying signal is in a
high impedance state.
18. A method according to claim 17 wherein decoding the coded
compressor activation signal further comprises activating the
compressor based on a state of the coded compressor activation
signal.
19. A method according to claim 10 wherein said decoding the coded
compressor activation signal within the second unit to determine
whether the compressor is to be activated comprises decoding the
coded compressor activation signal to determine which compressor
stage should be activated.
20. A blower unit for a heating, ventilation, and air conditioning
system, said blower unit configured to receive a compressor run
signal from a thermostat and comprising at least one apparatus
configured to generate a signal for combination with the compressor
run signal, said blower unit further configured to output a
combination of the compressor run signal and generated signal as a
coded compressor activation signal.
21. A blower unit according to claim 20 wherein said at least one
apparatus comprises a high frequency signal generator, said blower
unit configured to combine the output of said high frequency signal
generator with the compressor run signal.
22. A blower unit according to claim 21 further comprising an
electronically commutated motor comprising a motor controller, said
motor controller configured with said high frequency signal
generator.
23. A blower unit according to claim 20 further comprising a blower
motor, said at least one apparatus configured to combine the
compressor run signal with an identifying signal output by said
blower motor.
24. A blower unit according to claim 23 wherein said at least one
apparatus is configured to: output a coded compressor activation
signal at an approximate ground potential when the identifying
signal is in a low impedance state; and output a coded compressor
activation signal at an approximate 24 VAC potential when the
identifying signal is in a high impedance state.
25. A blower unit according to claim 20 wherein the coded
compressor signal comprises information regarding which stage of a
compressor is to be activated.
26. A unit for controlling operation of a compressor, said unit
comprising: a compressor run relay; and a decoder, said decoder
comprising a relay coil driver operable to change a state of said
compressor run relay, said decoder configured to receive and decode
a coded compressor activation signal from an external source, said
decoder operable to activate said relay coil driver based on the
decoded content of the coded compressor activation signal.
27. A unit according to claim 26 wherein said decoder comprises: a
high pass filter; and a detector, said high pass filter configured
to receive the coded compressor activation signal and output a
signal to said detector, said detector operable to activate said
relay coil driver based on an amplitude of the signal received from
said high pass filter.
28. A unit according to claim 25 wherein said decoder comprises: a
high pass filter; and a detector, said unit comprising a plurality
of compressor run relays each configured for activating a single
stage of a compressor, said decoder comprising a respective
plurality of relay coil drivers, said detector operable to activate
a specific said relay coil driver based on the decoded content of
the coded compressor activation signal.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to operation of heating,
ventilation, and air conditioning (HVAC) systems, and more
specifically, to operation of compressors, fan coils, and the like
using electronically commutated motors (ECMs).
[0002] Energy efficiency minimum requirements continue to be
tightened for HVAC equipment and systems. Therefore it has become
more important that outdoor condenser/compressor units and indoor
evaporator/air handler units are properly matched to one another so
that it is possible to achieve the desired energy efficiency
ratings.
[0003] Heretofore it has been a common practice, when servicing
HVAC equipment, to retain the working unit of the indoor/outdoor
pair and replace the non-working unit. In certain scenarios this
practice may result in a less than optimal performance of the
system, while in other cases, replacement of the non-working unit
may be acceptable.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, a heating, ventilation, and air conditioning
(HVAC) system is provided that includes a first unit and a second
unit. The first unit comprises a controller configured to output a
coded compressor activation signal that is based at least partially
on a compressor run signal received from a thermostat. The second
unit comprises at least a compressor relay and is configured to
receive and decode the coded compressor activation signal from the
first unit. The second unit is operable to operate the compressor
relay based on the decoded content of the coded compressor
activation signal.
[0005] In another aspect, a method for controlling operation of a
compressor within a heating, ventilation, and air conditioning
(HVAC) system is described. The method includes providing a
compressor run signal to a first unit, utilizing the compressor run
signal within the first unit to generate a coded compressor
activation signal, outputting the coded compressor activation
signal to a second unit that includes a compressor, and decoding
the coded compressor activation signal within the second unit to
determine whether the compressor is to be activated.
[0006] In still another aspect, a blower unit for a heating,
ventilation, and air conditioning (HVAC) system is provided. The
blower unit is configured to receive a compressor run signal from a
thermostat and comprises at least one apparatus configured to
generate a signal for combination with the compressor run signal.
The blower unit is further configured to output a combination of
the compressor run signal and generated signal as a coded
compressor activation signal.
[0007] In yet another aspect, a unit for controlling operation of a
compressor is provided. The unit comprises a compressor run relay
and a decoder. The decoder comprises a relay coil driver operable
to change a state of the compressor run relay. The decoder is
configured to receive and decode a coded compressor activation
signal from an external source and operable to activate the relay
coil driver based on the decoded content of the coded compressor
activation signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of a thermostatically controlled
heating, ventilation, and air conditioning (HVAC) system.
[0009] FIG. 2 is a block diagram of an indoor unit of HVAC system
that incorporates a high frequency generator.
[0010] FIG. 3 is a block diagram of an indoor unit of HVAC system
that incorporates a high frequency generator within an
electronically commutated motor of the blower.
[0011] FIG. 4 is a block diagram of an outdoor unit of an HVAC
system configured to operate with one of the indoor units of FIGS.
2 and 3.
[0012] FIG. 5 is a block diagram of an alternative embodiment of
indoor unit for an HVAC system.
[0013] FIG. 6 is a block diagram of an outdoor unit of an HVAC
system configured to operate with the indoor unit of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In one embodiment, the methods and systems herein described
prevent operation of a HVAC system where only an outdoor unit of an
indoor/outdoor unit pair has been replaced. However, these same
methods and systems allow operation of such HVAC systems when only
the indoor unit has been replaced. Such methods and systems results
in HVAC system configurations such that ever increasing efficiency
enhancing measures within indoor units can be utilized though the
outdoor unit may be of a different configuration.
[0015] Generally, and referring to FIG. 1, in HVAC systems 10, an
indoor evaporator/air handler unit 12 contains a circuit board
based controller 14 that receives a 24 volt control signal 16 from
a thermostat 18. In these embodiments, circuit board controller 14
is configured such that a subset 20 of the thermostat signals are
routed through to an outdoor condenser/compressor unit 22 to
control the operation of a compressor, fan, and other components of
outdoor unit 22. One such thermostat signal `Y` is typically
utilized to turn on the compressor by energizing a compressor relay
26 located within outdoor unit 22. In an alternative embodiment
(not shown), a relay coil driver, operating based on a signal other
than `Y`, may utilized to energize compressor relay 26.
[0016] FIG. 2 is a block diagram of an indoor unit 50 according to
one embodiment of the present invention that is communicatively
coupled to thermostat 52. Indoor unit 50 includes a controller
board 51 for routing signals to and from thermostat 52 as described
above. In the embodiment illustrated in FIG. 2, when a thermostat
signal 54 is present that is utilized for turning on one or more of
a compressor and fan within an outdoor unit, a high frequency
generator circuit 56 in the indoor air handler adds a high
frequency signal onto the 24 volt AC compressor run signal 58 going
to the outdoor unit. Such combined signals are sometimes referred
to herein as a coded compressor activation signal. High frequency
generator circuit 56, in one embodiment, is additionally configured
to eliminate any higher harmonics of the high frequency signal that
could cause radio frequency interference by filtering and/or low
duty factor operation.
[0017] In another embodiment, high frequency generator circuit 56
is configured to provide the coded compressor activation signal
which can be received by an outdoor decoder board (described
below). The frequency of the signal output by high frequency
generator circuit 56 is chosen to be high enough, 100 KHz for
example, such that the reactance found in a typical compressor
relay coil will not significantly attenuate the signal, and can be
easily separated from the 24 volt, 60 Hz, compressor run signal
utilizing an inexpensive filter. As further described below, an
absence of the high frequency signal at signal Y1, which is output
to an outdoor unit, will not allow activation of the compressor
associated with specific embodiments of outdoor compressor units,
as further described below.
[0018] FIG. 3 is a block diagram of an alternative embodiment for
an indoor unit 100. In this embodiment, a high frequency generator
(not shown, but similar to high frequency generator circuit 56) is
integrated into a motor control 102 of an ECM 104 that is powering
a blower 106. The embodiment of FIG. 3 provides an additional
operational feature to that described with respect to indoor unit
50 (shown in FIG. 2) in that ECM 104 becomes a key enabling
element. Since the high frequency signal is generated within ECM
104, a possibility of tampering within indoor unit 100 to bypass
the interlock provided through utilization of the high frequency
compressor activation signal may be significantly reduced.
Operationally however, indoor unit 100 provides the same
capabilities as does indoor unit 50 (shown in FIG. 2), that is, an
absence of the high frequency signal at signal Y, which is output
to an outdoor unit, will not allow activation of the compressor
associated with specific embodiments of outdoor compressor units,
as further described below.
[0019] Indoor units 50 and 100, however, are operable with existing
outdoor units, for example, those that operate compressors therein
based upon receiving a 24 VAC signal from a thermostat. Though
indoor units 50 and 100 impose a high frequency signal upon the 24
VAC thermostat signal, existing outdoor compressor units are
capable of recognizing the 24 VAC portion of the coded compressor
activation signal and controlling operation of their compressors
based on whether or not the 24 VAC signal is present.
[0020] FIG. 4 is a block diagram of an outdoor unit 150 according
to one embodiment of the present invention. In the embodiment,
outdoor unit 150 includes a decoder circuit 152 for receiving coded
compressor activation signals. Decoder circuit 152 includes a high
pass filter 154, a detector 156, and a relay coil driver 158 that
outputs a signal for operating compressor relay 160.
[0021] Outdoor unit 150 utilizes the high frequency coded
compressor activation signals generated by either of indoor units
50 (shown in FIG. 2) and 100 (shown in FIG. 3) to determine whether
to activate a compressor (not shown) by applying a signal to
compressor run relay 160. More specifically, through incorporation
of high pass filter 154 and detector 156, unless a high frequency
signal is input into outdoor unit 150 at signal Y, relay coil
driver 158 will not be enabled and the compressor will not run. The
signal at Y must be of a frequency high enough to pass through high
pass filter 154 and of sufficient amplitude to cause detector 156
to output a compressor activation signal.
[0022] Now referring to FIG. 5, an alternative embodiment for
generating a coded compressor activation signal is illustrated.
Specifically, referring to the block diagram of indoor unit 200, a
control board 202 and a blower motor 204 are included. In a
specific embodiment, blower motor 204 is an electronically
commutated motor. In the illustrated embodiment, a compressor run
signal 206 is combined with an identifying signal 208 from indoor
blower motor 204 using a resistor 210. This results in a coded
compressor activation signal 212 that is sent to an outdoor unit
over the compressor run signal wire. In an embodiment, the indoor
blower motor terminal changes its impedance in step with a changing
state of identifying signal 208 so that the composite compressor
activation signal 212 will be near ground potential when the output
terminal of the blower motor is in a low impedance state, and at an
approximately 24 VAC potential when it is in a high impedance
state.
[0023] Since composite compressor activation signal 212, also
labeled as Y' in FIG. 5, cannot supply enough current to drive the
compressor relay of an outdoor unit, due to the presence of
resistor 210, a source of 24 VAC is needed in any outdoor unit that
is utilized with indoor unit 200. In one embodiment, the ECM
operating as the blower motor is configured with an open collector
output channel, which is utilized to provide identifying signal
208. In various embodiments, identifying signal 208 can consist of
a frequency code or a pulse code that is received by the decoder
board in the outdoor unit. This output channel is configured in a
specific embodiment so that indoor unit can provide identifying
signal 208 only during a positive portion of the AC signal from
control board 202, as the ECM incorporates a diode that clamps the
negative portion of the AC signal.
[0024] FIG. 6 is a block diagram for an outdoor unit 250 that is
operable with the indoor unit 200 of FIG. 5. Specifically, outdoor
unit 250 includes a decoder board 252 that includes a transient
filter 254 receiving composite signal 212 from indoor unit 200.
Decoder board 252 also includes a processing unit (microcontroller
256) that receives signals through transient filter 254 and
controls operation of relay coil driver 258. Relay coil driver 258,
in conjunction with a DC bias power supply 260 and a 24 VAC supply
262, control operation of compressor run relay 264, thereby
controlling operation of a compressor (not shown).
[0025] In one embodiment, the components of decoder board 252
evaluate the signal on Y' for the presence of a combined compressor
run signal and identifying signal from the ECM motor 204 (shown in
FIG. 5). In this embodiment, decoder board 252, through filter 254
and processor 256, are able to discriminate between a positive
voltage containing both the blower identifying signal and a half
wave DC signal (the compressor run signal) or no signal. If the
compressor run signal is present with or without the blower
identifying signal, compressor relay 264 will be energized. If a
preset time elapses without processor 256 detecting the identifying
signal, compressor relay 264 will be deenergized and locked out for
a predetermined time. Otherwise the compressor (and condenser fan)
will be allowed to run.
[0026] As described above, if a standard outdoor unit (i.e., not
one of the above described embodiments) is to be connected to one
of the above described indoor units, the compressor activation
signal has to be connected to the same terminal as the compressor
signal thermostat, so that the outdoor unit is provided with a
typical 24 VAC run signal for activating the compressor, though the
24 VAC signal may be combined with a high frequency signal or other
frequency coded or pulse coded signal.
[0027] If an outdoor unit is utilized that is configured to be
paired with one of the above described indoor unit, it will contain
a decoder circuit (see outdoor unit 250 shown in FIG. 6) or filter
circuit (see outdoor unit 150 shown in FIG. 4). The output of the
decoder or filter is connected to the input of a relay driver
circuit, which in turn switches the 24 volt AC to the compressor
relay coil (158 or 258). Such a configuration makes an outdoor unit
unresponsive to a typical 24 VAC, 60 Hz, control signal, but
responsive to the frequency or coded signal received from one of
the above described indoor units.
[0028] If one of the above described outdoor units 150 or 250 is
connected to an indoor unit that does not have the identifying, or
high frequency, signal, the compressor will be prevented from
operating since a typical 24 VAC, 60 Hz, compressor run signal will
not satisfy the conditions needed to pass the compressor activation
signal through decoder board 252 or the combination of filter 154
and detector 156.
[0029] As described above, the methods and systems prevents the
operation of an outdoor condenser/compressor unit with an indoor
fan coil unit that is not configured to operate with the indoor fan
coil unit, while allowing the operation of other outdoor
unit/indoor unit combination. Such configurations allow an HVAC
system that may include one or more replacement components to
comply with increasingly rigid energy efficiency ratings while
providing the performance desired by users of such HVAC
systems.
[0030] Additionally, two stage compressor systems within outdoor
units are becoming popular because of the higher efficiency
attainable when they run at a lower capacity stage. The methods and
systems described herein are easily extensible to such two stage
compressor systems, for example, utilizing two different high
frequency signals for selection of the two compressor stages in
combination with one or more of a separate relay and driver signal
for each stage and a single relay utilized in conjunction with a
switching circuit to provide either of a first stage connection and
a second stage connection to the compressor.
[0031] While the invention has been described in terms of various
specific embodiments, those skilled in the art will recognize that
the invention can be practiced with modification within the spirit
and scope of the claims.
* * * * *