FIELD OF INVENTION
The present invention generally relates to the “Sequential start up control
panel for the Air Conditioning plants”. More particularly, the invention
relates to the Full automation of the Sequential Start-up of the AC
plants, thereby eliminating the need for manual operations and direct
operation by the shop personnel.
BACKGROUND OF THE INVENTION
The Clean room manufacturing facilities are usually provided with AC
plants for the purpose of providing conditioned atmosphere to the
manufacturing activities.
Primarily, the AC plant consists of Chiller units, Air handling units (AHU)
& pumps forming the refrigeration circuits. The operation of the AC plant
requires careful sequential start up in the order of 1) AHUs, 2) Pumps
and 3) Chiller units. Or else, severe incidents involving the damage of the
AC plants are liable to occur.
The conventional systems require an AC plant operator for carrying out
the sequential start-up of the AC plants. 2 AC plant operators need to be
assigned in 2 shift operations for performing the sequential start up
activities. The chiller plants contain many in-built safety features and do
not need continuous monitoring.
Hence, there is a dire need for the Design & Development of “Fully
automated Sequential Start up control panel” for the AC plants to
overcome the above drawbacks.

OBJECTS OF THE INVENTION
An object of the invention is to overcome the aforementioned and other
drawbacks existing in prior art systems and methods.
More particularly, it is an object of the invention to develop a Fully
Automatic Sequential Start up control system for the AC plant operation,
thereby obviating the need for manual operations.
Still another object of the invention is to develop a Fully Automatic
Sequential Start up control system for ensuring safety in the AC plant
operation.
These and other objects and advantages of the present invention will be
apparent to those skilled in the art after a consideration of the following
detailed description taken in conjunction with the accompanying
drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION:
The present Application discloses a sequential start-up control system
for air-conditioning (AC) plants. The system further includes a first series
connection path between a first push button (1) to a contactor K1 (3).
Further, in an aspect, the system includes a second series connection
path between the contactor K1 (3) to a contactor K2 (4). In another
embodiment, the system includes a third series connection between a
contactor K2 -2 (4b) to a timer T1 (6). Furthermore, in an aspect, the
system includes, a fourth series connection between a timer T1 (6) to a
contactor K3 (5). Further, the system is provided with a fifth series
connection between the contactor K3-1 (5a) to a timer T2 (7). Further, in
another embodiment, the system contains a sixth series connection path

between the timer T2 (7) to a timer T3 (8) and further a seventh series
connection path between the timer T3 (8) and an indication lamp.
In another embodiment, the present application discloses a method of
controlling sequential start-up for air-conditioning (AC) plants. In an
aspect, a first push button (1) is pressed for initiating sequential start-up
control operations. The method further includes energizing a contactor
K1 (3), which results in initiating self-latching of contactor K2 (4),
thereby leading to switching on of a plurality of air handling units
(AHUs). Furthermore the method includes simultaneously activating a
timer T1 (6) by the contactor K2 (4) for providing (i) a time delay, and (ii)
switching ON of several circulation pumps via multiple starters. In an
aspect, the multiple starters are pulse started using a contractor K3 (5).
Further, the method includes activating a timer T3 (8) for providing (i) a
time delay and (ii) switching ON of a plurality of chiller units.
The above and additional advantages of the present invention will
become apparent to those skilled in the art from a reading of the
following detailed description when taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The drawings refer to embodiments of the invention in which:
Figure 1 – Illustrates a Flowchart for the “Sequential start up control
system for the Air Conditioning plants”.
Figure 2 – Illustrates a Schematic diagram for the “Sequential start up
control system for the Air Conditioning plants”.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Although the disclosure hereof is detailed and exact to enable those
skilled in the art to practice the invention, the physical embodiments
herein disclosed merely exemplify the invention which may be embodied
in other specific structure. While the preferred embodiment has been
described, the details may be changed without departing from the
invention, which is defined by the claims.
It will be apparent, however, to one of ordinary skill in the art that the
present invention may be practiced without specific details of the well
known components and techniques. In other instances, well known
components or techniques have not been described in detail but rather in
Figures in order to avoid unnecessarily obscuring the present invention.
Further specific numeric references should not be interpreted as a literal
sequential order. Thus, the specific details set forth are merely
exemplary. The specific details may be varied from and still be
contemplated to be within the scope of the present invention. The
features discussed in an embodiment may be implemented in another
embodiment.
Moreover, occasional references to the manual Sequential Start-up
control are made in order to better distinguish the present inventive
disclosure discussed later in greater detail. Few of the details pertaining
to the approach disclosed in the invention are well-known in the art, and
therefore, are described herein only in the detail required to fully disclose
the present invention.

Improving upon the conventional techniques discussed at length above
(background), in the present disclosure the novel and inventive design for
implementing automatic Sequential Start-up control system as shown in
Figure 1-2 clearly makes Sequential Start-up control system as disclosed
in the present application advantageous over the existing arts as would
also become clearer to the knowledgeable in the art with the particulars
of the aforesaid techniques being described below in greater detail.
Fig.1 shows a flowchart for depicting the sequential start up control
system for the air conditioning plants. In the preferred embodiment, the
first stage start up involves starting up of the air handling unit (AHU),
the second stage start up entails staring up of the pumps followed by a
third stage start up where the chiller units are started up. Herein, in an
embodiment, the necessary is Time delay is 10 seconds which is to
ensure the safe start up of higher current rated components.
Turning now to Figure 2 which shows a Sequential start up control
system for the Air Conditioning plants. The components/elements
instrumental in designing a Sequential start up control panel are
enumerated below:
First Push Button (1): Switch ON button for initiating the Sequential
start up operation.
Second Push Button (2): Switch OFF button for stopping the AC plant
operation.
Contactor K1 (3): The contactor will be energized upon the pressing of (1)
and initiates the self-latching mechanism via Contactor K2 (4). In an
aspect, Contactor K1 (3) is also used for the pulsed switching one of the
Air handling unit starters.

Contactor K2 (4): The contactor is used for self holding upon the pressing
of (1) and forced unlatch upon the pressing of (2).
Contactor K3 (5): The contactor is used for the pulsed starting of the
Pump Motor starter.
Timer T1 (6) : The timer will get activated through (4) and provides the
necessary time delay for the switching on of the water circulation pump
via the Motor starter as a part of the sequential start up. Timer T2 (7):
The timer is used as the OFF delay timer for (6).
Timer T3 (8): The timer will get activated by (7) and is used to switch on
the chiller units.
Remote mode (9): They are rotary switches deployed for isolating the
sequential start up mechanism and operating the AC plant operation in
manual mode. The remote selector switch (9) not a part of the sequential
start up. In a preferred embodiment, it will help to turn off the sequential
start up mechanism and to switch on the equipments manually. It is
used during local maintenance activities for Safety reasons.
Chiller select switch (10): Implemented to individually ON/OFF the
chiller units. Based on the external climatic conditions, the chiller select
switch (10) facilitates turning ON/OFF the individual chiller as per User’s
decision. The chiller select switch (10) delinks the chiller operation from
the Sequential start up.
Further, the automated control system consists of the below mentioned
steps:
The user has to press the first Push Button (1) for initiating the
sequential start-up operations. Upon the pressing of the first Push

Button (1), the following sequential operations are established through
the control panel logic.
At first, the contactor K1(3) will be energized and initiates the self-
latching mechanism of the contactor K2 (4) which in turn will switch on
the Air handling units by means of pulsed switching on of the Fully
automated Star delta starters.
The contactor K2 (4) will simultaneously activate the Timer T1 (6) and the
(6) will provide the necessary time delay and switches on the water
circulation pumps via starters.
Followed by the Timer T3 (8) gets activated and provides the necessary
time delay and switches on the chiller units.
Safety features during maintenance activities are established by the
provision of Remote mode selector switch (9) which bypasses the control
panel start up and allow the direct start-up of the motors using starters.
Further, as shown in Figure 2, the contactors K1, K2, K3 are represented
as the coil portions. Furthermore, contact portions i.e. K2-1 (4a), K2-
2(4b) and K3-1(5a) are represented in the manner as shown in Figure 2.
The foregoing is considered as illustrative only of the principles of the
invention. Furthermore, since numerous modifications and changes will
readily occur to those skilled in the art, it is not desired to limit the
invention to the exact construction and operation shown and described.
While the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by the
claims.

We Claim:
1. A sequential start-up control system for air-conditioning (AC)
plants comprising:
a first series connection path between a first push button (1)
to a contactor K1 (3);
a second series connection path between the contactor K1 (3)
to a contactor K2 (4);
a third series connection between a contactor K2 -2 (4b) to a
timer T1 (6);
a fourth series connection between a timer T1 (6) to a
contactor K3 (5);
a fifth series connection between the contactor K3-1 (5a) to a
timer T2 (7);
a sixth series connection path between the timer T2 (7) to a
timer T3 (8);
a seventh series connection path between the timer T3 (8)
and an indication lamp.
2. The system as claimed in claim 1, further comprising connecting a
push button (2) and a contactor K2 -1 (4a) in series such that
there is a parallel connection path between the contactor K1 (3) in
the second series connection path and the push button (2) and the
contactor K2 -1 (4a) connected in series.
3. The system as claimed in claim 1, further comprising the first
series connection path between the first push button (1) through a
remote mode selector switch (9) to the contactor K1 (3).
4. The system as claimed in claim 1, further comprising the second
series connection path between the contactor K1 (3) through the
remote mode selector switch (9) to the contactor K2 (4).

5. The system as claimed in claim 1, further comprising the sixth
series connection path between the timer T2 (7) through a chiller
select switch (10) to the timer T3 (8).
6. A method of controlling sequential start-up for air-conditioning
(AC) plants, wherein a first push button (1) is pressed for initiating
a sequential start-up control operations, the method comprising:
energizing a contactor K1 (3), which results in initiating self-
latching of contactor K2 (4), thereby leading to switching on
of a plurality of air handling units (AHUs);
simultaneously activating a timer T1 (6) by the contactor K2
(4) for providing (i) a time delay, and (ii) switching on of a
plurality of circulation pumps via a plurality of starters,
wherein the plurality of starters are pulse started using a
contractor K3(5); and
activating a timer T3 (8) for providing (i) a time delay and (ii)
switching ON of a plurality of chiller units.
7. The method as claimed in claim 6, further comprising bypassing
the sequential start-up control system via a remote mode selector
switch (9).
8. The method as claimed in claim 6, further comprising delinking
the plurality of the chiller units from the sequential start-up
control method via a chiller select switch (10).