FIELD OF THE IhTVENTION:
The present invention relates to a phase selector device The present invention in particular
relates to an automatic phase selector device add on with any distribution board and which is
independent of the phase of fault. More particularly, the invention relates to a compact phase
selector device retrofittable with power distribution boards for automatic switching to
priority-based phases during power intemrption or under/over-voltage condition.
BACKGROT]IYD OF TIIE II\TVENTION
The power instability in developing countries creates a need for automation of phase
selection to back up an utility supply. This further necessitates the automation in a
distibution system because of hike of rate of power outage and low voltage output. Most of
the residential and commercial applications are dependent on power supply and if the process
of changeover is manual, not only a considerably time is wasted, but it may also cause
hindrances in power-dependent important activities.
US Patent No. 8,222,941 provides a phase selector including a plurality of buffers, a
multiplexer, a first inverter, and a selecting circuit. Each of the buffers provides a clock
signal, and the clock signals have different phases. The multiplexer selectively outputs one of
the clock signals as a switch signal according to a first control signal. The input terminal of
the first inverter receives a second control signal and the selecting circuit tansmits the
second control signal of the selecting signal or the inverted signal to the output terminal of
the phase selector according to the logic state of the switch signal.
US Publication No. 20120078428 provides a smart metering device for connecting an end
user mains network to a multiple phase power distribution network and monitoring
consumption on the end user mains network. The device is provided with a phase selector by
means of which the outputs can be switched from one phase to another. When a plurality of
end user mains networks are connected to one power distribution network part by means of
the device, the power distributor can remotely control the phase selectors at the different end
user mains networks to redistribute the load over the different phases of the distibution
network.
-3-
Publication No. CN 203415991 describes a low voltage automatic phase change system
which comprises a distribution transformer connected with an air switch which is further
connected with a three-phase residual current circuit breaker. A single-phase operation
current value and a three-phase operation current value are compared; according to a threephase
unbalance standard, automatic load adjustment is carried out in a set load adjustment
time period; WW three-phase switching or load disconnection is carried out, so that the
unbalance degree of three-phase current is kept in an allowed safe range; the problem that the
distribution device is burned due to three-phase curent wrbalance is avoided; and the safe
operation of the distribution device is ensured.
Publication No. CN 203352185 discloses a low-voltage reactive automatic split-phase
compensation device of a distribution room. Three current transformers are respectively
sleeved on three live wires, one ends of secondary lines of the three current tansformers are
connected to a zero power measuring unit, the other ends of the secondary lines of the three
current transformers are respectively connected to a first input end, a second input end and a
third input end of the zero power measuring unit, a fust way of the output end of the zero
power measuring unit is synchronously connected to control ends of three relays, a second
output end, a third output end and a fourth output end of the zero power measuring unit are
respectively connected to a three-phase power supply and first power ends of the three relays,
a fifth output end of the zero power measuring unit is synchronously connected to a null line
and second power ends of the three relays, and the output ends of the three relays are
respectively connected to the null line through three single-phase capacitors.
Publication No. CN 203554058 describes a power supply circuit of an automatic change-over
switch controller. A frequently-used power supply and a standby power supply are subjected
to voltage reduction through a lirst three-phase transformer and a second three-phase
transformer respectively. The power supply circuit of the automatic change-over switch
controller adopts the dual power supply power supplying mode, an input end of the power
supply circuit is led from a three-phase alternating current of each path of power supply, the
other phases of the path of the power supply can be standby even if one phase is powered off
and the operation reliability of the automatic change-over switch contoller can be greafly
improved.
-4-
Publication No. CN 103872759 provides a method and apparatus for determining the
conversion of automatic electrical switch contoller, it's easy operation, high degree of
automation" improve the accuracy of automatic tansfer switching and reliable, ensuring safe
use of elecnicity.
Publication No. CN 202565020 provides a failure detecting circuit of an automatic changeover
switch which includes a first voltage detection circuit, a second voltage detection
circuit and micro-processing chip lC, micro-processing chip IC connected to the first voltage
detecting circuit and the second voltage detecting circuit, a first voltage detection circuit and
the first phase line and the neutal line N supply is connected, a second voltage detection
circuit and the power supply line of the second phase and the third phase connection.
Publication No. CN 202565020 provides a low voltage intelligent double power source
change-over switch for automatic switching of dual power, especially with digital signal
acquisition, processing capabilities to achieve intelligent dual power conversion switchgear,
automatic transfer switching equipment ATSE the PC level, belong to the field of lowvoltage
elecnical equipment.
Publication No. EP 2665346 provides a power supply arrangement for a luminaire
comprising a connector for connection to a pollphase supply line and a device for phase
selection. The phase selection device allows selective connection of the operating device
with a certain phase conductor of the supply line. The device for phase selection is embodied
as an electonically controllable phase selector and has a control input of by an electonic
contol unit and is driven by the operating device and thus the selection of the phase
conductor allowed.
Publication No. JPS60ll79l5 describes automatic actuation of a circuit to detect and decide
successively plural delay signals in order to obtain the coincidence at all times between the
prescribed value of a register and a reference signal and then delivering only the signal
coincident with said prescribed value.
-5-
Publication No. CN 203434738 describes a three power supply automatic changeover switch
conholler. Outputs of a first transformer, a second transformer and a third fransformer are
respectively connected with a frst filter rectification circuit, outputs of a fourth tansformer,
a fifttr transformer and a sixth transformer are respectively cormected with a second filter
rectification circuit, outputs of seventh transformer, an eighth transformer and a ninth
transformer are resp€ctively connected with a third filter rectification circuit, a main contol
CPU circuit is connected with an external output circuit, a power supply circuit, a key circuit,
an LCD display circuit, a contol output circuit and an RS485, the first filter rectification
circuit, the second filter rectification circuit and the third filter rectification circuit are
respectively connected with a first CPU circuit, a second CPU circuit and a phase difference
acquisition circuit, the phase difference acquisition circuit is connected with the second CPU
circuit, the first CPU circuit and the second CPU circuit are respectively connected with the
main control CPU circuit by SPI buses.
Publication No. CN 201733095 describes a three-phase current balancing and automatic
adjustment switch characterized in that three one-phase switches which are independent to
each other and are respectively provided with an interlocking device are arranged in a shell.
The system can realize ttre switching of a certain one-phase load among the phase lines of a
three-phase power supply circuit, and thereby automatically realizing the uniform load
distribution of all the phases, and meanwhile, the utility model has simple structure, economy
and practicability, operates reliably, and can be widely used for low voltage power supply
and power network operation fields.
Although the prior art teaches automatic phase selection systems but fails to disclose a phase
selection system which can bE retrofitted on power distibution boards.
According to prior art, manual selection of the phase in a distribution board is inescapable to
allow continuation of power supply, whenever there is phase intemrption, which interalia
wastes time. Moreover, this discontinuation of supply cause hindrances to important powerdependent
activities. Further, power fluctuations such as over-voltage or under-voltage
conditions can harm electical appliances.
-6-
Therefore, in view of the drawbacks associated with prior art, the present invention provides
a compact automatic phase selector device which can be added to any distribution board. It
automatically selects the next healthier phase based on user's choice whenever there is any
loss of power or power fluctuation.
It is therefore an object of the present invention to propose a compact phase selector device
retrofittable with power distribution boards for automatic switching to priority based phases
during power intemrption or under/over- voltage condition.
The priority pre-set by the user further enables input prioritization, whenever there is
problem in supply. For example, a priority input given by an user at R phase is R-y-B, and if
there is a loss of phase at R, the input will automatically shift to y phase if it is healthy.
AccordinglY, the LED assigned for Y-phase will start blinking. when R phase gets restored,
the input will shift back to R phase indicated by blinking of the corresponding LED.
Another object of the present invention is to propose a compact phase selector device
retrofittable with power distribution boards for automatic switching to priority based phases
during power intemrption or under/over-voltage condition, which displays an instantaneous
visual indication of the reason of fault including the phase on which the load is running.
A still another object of the present invention is to propose a compact phase selector device
retrofittable with power distribution boards for automatic switching to priority-based phases
during power intemrption or under/over- voltage condition, which operates independent of
the faulted phase.
Yet another object of the present invention is to propose a compact phase selector device
retrofittable with power distribution boards for automatic switching to priority-based phases
during power intemrption or under/over-voltage condition, which eliminates the lost time due
to automatic phase changeover.
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A further object of the present invention is to propose a compact phase selector device
retofittable with power distribution boards for automatic switching to priority-based phases
during power intemrption or under/over-voltage condition, which can be easily installed with
any distribution board in series.
A still further object of the present invention is to propose a compact phase selector device
retrofittable with power distribution boards for automatic switching to priority-based phases
during power intemrption or under/over- voltage condition, which is easy to manufacture,
cost effective and has a small size.
In accordance of the said objectives, the present invention provides a compact phase selector
device retofittable with power distribution boards for automatic switching to priority-based
phases during power intemrption or under/over-voltage condition.
The invention provides a solution to overcome power fluctuation or phase intemrption by
selecting the next healthiest available phase according to a priority set by an user. The
automatic phase selector device can be easily installed in series with any standard
distribution board and saves on the lost time due to elimination of prior art process of manual
changeover.
In a preferred embodiment of the present invention, each modular automatic phase selector in
automatic phase selector device comprising voltage sensing devices for each of the three
phases, a microcontroller unit, a relay control unit, a LED display unit and a keypad.
In another preferred embodiment of the present invention, the phase voltage sensing devices
(& y, B), power supply unit, relay control unit, LED display unit and keypad are connected
and controlled by the microcontroller unit.
In a still another embodiment of the present invention, the automatic phase selector device is
installed with power distribution board in series. The incomer for the
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distribution board is pre-connected with the automatic phase selector device and the outgoing
of the modular automatic ph.ase selectors are connected to the switchgears of the power
distribution board.
In yet another embodiment of the present invention, the voltage sensing devices of each R, y,
and B phases, senses the real-time voltage supply and steps down to a corresponding voltage
wave for electronic sensing. The sensed signal is sent to the microcontroller, which feeds on
5 volts and relay on 12 V from the power supply. The Keypad enables inputting of the user's
priority into the microcontroller to set the priority.
In a firther embodiment of the present invention, the modular automatic phase selector in
automatic phase selector device select the phase based on the first, second and third priority
set by the user as long as that particular phase is in healthy state to run the loads.
In a still further embodiment of the present invention, the microcontroller unit, during any
phase failure or under/over-voltage condition, sends signals to the relay control unit to shift
to the next healthy phase as pre-set by the user and is indicated by allowing blinking of the
corresponding LED at one per second.
If RYB priority sequence is selected at R phase, then the R phase voltage sensing device will
continuously monitor the R phase voltage. If the R phase is present and its phase voltage is
within the desired range, then the load will be allowed to run on the R phase only, which will
be indicated by the R phase LED blinking at a rate of I sec.
The phase switching device checks the voltage in Y phase, in case where the R phase goes
off i.e. fails (the LED will stop glowing). If the Y phase voltage is healthy, the
microcontroller unit sends a signal to the relay control unit which does the necessary
switching in less than 3 seconds. Moreover it also sends a feedback on the status indicator,
thus Y phase LED will now start blinking at the rate of I per second.
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In case the R phase voltage crosses beyond the over-voltage (or under-voltage) limit, the Rphase
LED will blink at a rate of 0.5 second (or 3 seconds), and the fault-indicator LED will
go on. The phase switching unit checks the voltage in Y phase and if it is healthy, the load
will be shifted to Y phase within 3 seconds and will be indicated by Y-phase LED blinking at
arute of I per second.
If it does not find Y phase as healthy, it will repeat the above procedure with B phase.
In still another embodiment of the present invention, in the event of restoration of the highest
priority phase, the entire load is automatically transferred to that particular phase in less than
3 seconds.
In another embodiment of the present invention, the automatic phase selector device of the
present invention is independent of the phase of fault.
In yet another embodiment of the present invention, the housing of the automatic phase
selector device comprises an outer cover; a box subassembly; four to six screws and at least
eight plastic plain washers.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered for limiting of its scope, for the
invention may admit to other equally effective embodiments.
Fig' I illustrates the general overview of the automatic phase selector device of the invention
showing an external view of thc device retrofittable with a power distribution board;
Fig' 2 illustrates a front view of the automatic phase selector device retrofittable with a power
distribution board;
Fig. 3 illushates right side view of the inventive device renofittable with a power distibution
board;
Fig. 4 illustrates top view of the device retrofittable with a power distribution board;
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Fig' 5 illustrates internal arrangement of the automatic phase selector device having a
miniature circuit breaker (MCB) and three modular automatic phase selectors mounted on a
DIN Rail.
Fig' 6 illushates a block diagram of modular automatic phase selector present in automatic
phase selector device according to the present invention;
AccordinglY, the present invention provides a compact phase selector device retofittable
with power distribution boards for automatic switching to priority-based phases to address
power fluctuations or phase intemrption in power supply by selecting the next healthiest
available phase according to the priority set by the user. The phase selector device of the
present invention does not require any manual work and is in no way concerned with phase
of fault' as the modular automatic phase selector automatically switches to a phase where the
power is availabre according to the priority set by the user.
Figure I illushates the general overview of automatic phase selector device rehofittable with
a power distribution board' The figures 2-4 describe the size and dimensions of the automatic
phase selector device which can be installed with any standard distribution board in series.
Knockouts holes are placed suitably at the outgoing and incoming sides to cable and wire the
connections in a neat and clean manner. The internal arangement view (as shown in fig. 5)
shows the modular automatic phase selector of each phase installed on a DIN rail along with
a MCB' where each phase selector can be set at a different priority setting. LEDs give an
indication of the phase on which the load is running at all times as well as the reason of fault,
if any' The housing of the automatic phase selector device incorporates an outer cover; a box
subassembly; four to six screws and at least eight plastic prain washers.
Figure 6 illustrates a block diagram of the intemal connectivity of the constituent
components of the inventive modular automatic phase selector (100). The automatic phase
selector (100) has & y, and B phase voltage sensing devices (r0, ll, and r2), a
microcontroller urit (13), a relay conhor unit (r4), aLED dispray unit (15) and a kelpad
(16)' The voltage sensing device of R, Y, and B phases are enabled to determine the realtime
voltage supply and step down to a desired voltage wave suitable for electronic sensing.
The sensed signal is
-1 lsent
to the microcontroller (13), which feeds on 5 volts and the relay control unit (14) on lZ
V from a power supply (17). The Keypad (16) inputs the user's priority into the
microcontroller (13) for setting the desired phase sequence. The status of the phase on which
the load is running, as well as fault (if any) is indicated by the LED display unit (15). The
LED display unit (15) has three LEDs each for R, Y and B phase & one ofault, LED.
The automatic phase selector device of the present invention is independent of the phase of
fault. At phase R, let the priority sequence R-Y-B be set by the user. If the R phase is present
and its phase voltage is in the desired ftulge, then the load runs on the R phase only and is
indicated by causing the R phase LED blinking at a rateof I per second. But if the R phase
goes off i'e' fails and the LED stops glowing, then the automatic switching unit checks the
voltage in Y phase. If it finds the Y phase is healthy, then it performs the necessary switching
to the Y phase within 3 seconds and the Y phase LED will start blinking at a rate of I per
second' In the event of restoration of the highest priority phase, the entire load is
automatically transferred to that particular phase within 3 second.
The automatic phase selector device of the present invention can be easily retrofitted with
any standard power distribution board. The device is easy to manufacture, cost effective and
has a compact size.
Numerous modifications and adaptations of the system of the present invention will be
apparent to those skilled in the art, and thus it is intended by the appended claims to cover all
such modifications and adaptations which fall within the true spirit and scope of this
invention.

WE CLAIM:
l. A compact phase selector device retrofittable with power distribution boards
for automatic switching to priority-based phases during power intemrption or under/overvoltage
conditions, the automatic phase selector device having provision for a plurality of
modular automatic phase selector. The automatic phase selectors (100) for each phase b"ing
installed on a DIN rail in the automatic phase selector device, alongwith a miniature circuit
breaker, wherein each of the phase selector is capable of operating with different priority
settings, the phase selector comprising
a plurality of voltage sensing devices (10,1 1,12) each assign for R y,& B phases;
a microcontroller unit (13);
arclay control unit (la);
a LED display unit (15); and
a keypad (16),
wherein the plurality of sensing devices (10,1l,l2) is enable to determine the realtime
voltage supply including stepping down the voltage at a desire voltage wave
for electronics sensing , wherein the microcontroller operating on 5 volt supply
from the power supply (17) and receiving the sensed signal from the sensing
devices (l0,l l,l2), wherein the relay control unit (14) operating on 12 volts from
said power supply (17) , wherein the keypad (16) inputting an users priority into
the microcontoller (13) for setting the prioritized phase sequence, and wherein
the LED display unit having phase-corresponding numbers of LEDs including a
LED assign to indicate a fault, the phase selector is configured to :_
- select a phase based on the priority set by the users so Iong that particular
phase remains in healthy set to run the loads;
- nansit through the microconholler unit signals to the relay conhol unit to
shift to a next healthy phase in the event ofa phase failure or under/overvoltage
condition of the supply, the corresponding LED indicating the
phase shift condition through blinking at one per second; and
‐
13¨
¨ transfer the entire load tO the original phase when the supply is restore to
no.1.lal,characte五zed in that the prioHty sequence is sensed iteratively to
momtOr the phase v01tage sO as to select the mott hedthy phase at any
point Oftilne inv01ving phase failllre or under/Over‐ v01tage condition。
2.TЪЮ device as claimed in claim l,wherein the device is Operable with any distributiOn
board in seHes,such that the incOmer of the distribution board is precOlmected
tO the
automatic phase selectOr device and the outgoing Of the modular autOmatic phase selectors
are comected tO the power distribution devices that are installed in the distributiOn bOard.
3.The device as claimed in claim l,00mpnsing prionty seting feature,wherein the de宙
ce is
enabled tO select a phase based On the frst,second and third p五
0五ty set by an llser as 10ng as
that particular phase is in a healthy state lo rlm the 10ads,the p五
OHty sequence clЮ ice is set
by the user llsing the keypad which is inputted into the rnicrOcOntroller unlt.
4.L device as claimed in claim l,wherein the phase v01tage serlsing devices,the relay
control llnit,the LED display llnit and the keypad are intercorlnected and cOntrolled by the
microcOntЮ ller unit,wherein the v01tage sensing devices fOr each phase checks fOr presence
of v01tage supply Or healthy v01tage supply on any of the■
口ee sensing devices and step
down the v01tage tO a desired v01tage wave suitable for transmiting the sellsed signal to the
microcOntroller unit。
5。The de宙ce as claimed in claim l wherein during any 10ss Ofphase or under/Over_v01tage
condition beyond pel.1.issible limits,the lnicrocOntroner llnlt translnits a signal tO the relay
control unit which automaticJly s宙tches tO the next hedthy phase as per the selected phase
sequence unthin a speciflc peHod Of tiine which is indicated by a110wing blinking of the
corresponding LED。
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6. The device as claimed in claim I wherein the LED display units indicates the phase on
which the load is running at all times and in case of fault, and wherein the LED gives an
indication of the reason of fault such as phase ottagelover-voltage or under-voltage.
7. The device as claimed in claim I wherein in the event of restoration of first priority phase,
the entire load is automatically transferred to ttrat particular phase within a specific period of
time.
8. The device as claimed in claim l, wherein the device is independent of the phase of fault.
9. The device as claimed in claim l, cornprising an outer cover; a box sub-assembly; at least
four to six screws and at least eight plastic plain washers.