Improvements in the Method of and Means for Distributing Electric Currents.
Year: 1892

page_text: Date of Application, 15th July, 1892
Complete Specification Left, 11th Apr., 1893-Accepted, 10th June, 1893
PROVISIONAL SPECIFICATION.
Improvements in the Method of and Means for Distributing Electric
Currents.
I, GISBERT KAPP, of 31 Parliament Street, Westminster, in the County of
Middlesex, Electrical Engineer, do hereby declare the nature of this invention to
be as follows:-
This invention relates to the method of and means for the distribution of electric
currents by the "sub-station system "in which high pressure currents are supplied
from the central station to a transformer or transformers placed at the sub-station
or at sub-stations in the district to be served, the low pressure or secondary circuits
of the transformer or transformers being connected in parallel with the distributing
mains, and the primary or high pressure mains (hereinafter called the "feeders ")
being connected at the central station in parallel, by means of omnibus bars or
omnibus terminals, as is well understood. It is well known that this system of
distribution as at present carried out, has a low efficiency during those hours of the
day in which the demand for current is small, the cause of this low efficiency being
the waste of power which is proceeding at all times, whether the transformers be
lightly or heavily loaded. To reduce this waste of power, it is necessary to
disconnect from the feeders and from the distributing circuits, (i.e. from the
primary and from the secondary) such transformer or transformers as may at any
time be too lightly loaded, the service in the distributing mains being then supplied
by the transformer or transformers which are left in circuit. As the demand
increases, as many of the previously idle transformers are connected up as may
be required.
I provide, according to my present invention, methods of and means for cutting
the transformers out of, and putting them into, action, from the central station, and
for ascertaining at that station whether any particular transformer at any sub-
station is or is not connected with the feeders and distributing circuits. My
improvements are applicable both to continuous and to alternate current distribution,
but I will at present limit my description to the alternate system, since the
modifications which may be required for the continuous system are of a very
obvious nature.
I will first describe the nature of my invention as applied in an installation
where several transformers to be separately controlled are connected to a single
feeder or are served by a network of feeding mains. In this case, I arrange, in
combination with each of the. transformers to be controlled, a compound switch
which is capable of controlling its primary connections with the feeders and its
secondary connections with the distributing mains. The primary element of the
compound switch is of the single-pole type, the secondary element may be either
of the single or of the double-pole type. The two elements of the switch are
mechanically connected, but in order to avoid undue sparking, the contacts are
arranged in such a manner that the feeder (primary) circuit is broken before the
secondary. The compound switch is operated by an electromotor, through suitable
gearing and devices, in such a manner as to produce a quick make or a quick break
after the lapse of a sensible interval of time from the starting of the motor.
In order to make my further description clearer I will call the omnibus bars or
terminals at the central station, A and B, and the feeder wires connected with
them a and respectively. At the sub-station, the single-pole element of the
compound switch is inserted between the a feeder wire and one terminal of the
transformer, the other terminal of the transformer being connected directly with
the feeder wire. One terminal of the motor is connected, on the transformer

page_text: side, to the primary element of the compound switch, whilst the other motor
terminal is connected with an insulated wire of small section, which is taken back
to the central station along with the feeder. This small insulated wire I call the
"motor wire," and it is connected at the central station, with a suitable double-
contact switch, by means of which it may be connected with either of the two
omnibus bars or terminals. An ampèremeter may be included in the motor circuit
at the central station, for the purpose hereinafter described. If the transformer be
in circuit, and it is desired to cut it out, I join the motor wire with the B omnibus
bar, whereupon the motor will be energised by a current taking the course out by
the a feeder, through the primary element of the compound switch at the sub-
station, through the motor, and back through the motor wire to the B omnibus bar,
or the reverse. When the motor has performed a certain number of revolutions,
more or less, the sub-station switch snaps off, and cuts the transformer out, at the
same time opening the motor circuit and consequently stopping the motor. If, on
the contrary, the transformer be out of circuit, and it be desired to join it in, the
motor wire is connected with the A bar, when a circuit will be closed through the
motor wire, the motor, the primary of the transformer, and the feeder. The motor
is thus set in motion and closes the compound switch. When the switch has been
closed, the difference of potential between the two motor terminals, is only that due
to the ohmic resistance of one feeder wire, and the motor current is instantly
reduced to a very small fraction of its previous amount, and the motor stops.
The moment when the compound switch at the sub-station is either opened or
closed, is indicated on the ampèremeter in the motor wire by a sudden drop in the
current. Consequently, by watching the ampèremeter, and tentatively joining the
motor wire with either of the omnibus bars, it is possible at any moment to
ascertain whether or not the transformer is in circuit.
The motor wire may also be employed for ascertaining the primary pressure at
the sub-station in the following manner :-One terminal of a suitable voltmeter
(preferably an electrostatic voltmeter), is connected with the B omnibus bar, and
the other alternately with the A bar, and with the motor wire. If the two feeder
wires be of equal section, then the difference between the two readings gives half
the voltage loss in the feeder.
I will now describe the application of my invention in the case where each
transformer is supplied by a separate feeder. In such a case, the methods and
appliances hereinbefore described may be suitably employed, but I may insert a
double-pole switch into the feeder at the central station, and connect the two
terminals of the motor wire switch, not with the omnibus bars, but with the corre-
sponding feeder wires on the other side of this double-pole switch. The advantage
of this arrangement is, that when taking the transformers off, the feeder current
may be broken at the central station before switching the motor on, so that the
primary element of the compound switch at the sub-station interrupts only the
motor current, whilst the secondary element of the switch interrupts an equivalent
amount of the low pressure current, the power for working the motor being in this
case derived from the distributing mains. To put the transformer into cirenit
again, the central station double-pole switch is first closed, and then the motor
switch, the action of the apparatus being the same as hereinbefore described.
In a modification of my improvements, I may omit the primary element of the
compound switch at the sub-station, so that the motor will control only the low
pressure or secondary circuit through the switch. In this case the feeder current
is controlled at the central station by a double-pole switch and the motor switch has
only a single contact for making connection with the feeder wire, in which wire or
circuit is inserted an ampèremeter. To cut out the transformer, the feeder is first
switched off the omnibus bars, and then the motor is switched on. The power for
working the motor is derived from the distributing mains, and as soon as the
secondary switch has been opened by the motor, the supply of power is cut off
and the motor stops. To put the transformer on again, the feeder is first switched
on and then the motor switch whilst watching the ampèremeter. The moment the

page_text: secondary circuit at the sub-station has been closed, the needle of the ampèremeter
gives a jerk, when the motor is switched off and stopped.
In a further modification of my improvements, I employ single-pole switches at
the central station end of the feeder, and a double contact motor switch, the two
contacts being connected to the B bar and to the feeder respectively, on the other
side of the switch. To cut out the transformer, I proceed as hereinbefore described
with reference to the modification set forth in the preceding paragraph. To put in
the transformer, I first close the switch on the a feeder wire, and then join the
motor switch to the B bar. At the central station a voltmeter is connected across
the two feeder wires. By watching the voltmeter, it will be seen that at first no
pressure is indicated, but as soon as the secondary switch at the sub-station has
been closed, pressure is produced at the primary terminals of the transformer, and
this is indicated by the voltmeter. The motor switch is then taken off, and the
switch of the feeder is put on, which completes the operation.
It is thus possible to utilise the motor wire in all cases, as a means for
ascertaining the pressure at the primary terminals of the transformer.
Dated this 11th day of July A D. 1892
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Method of and Means for Distributing Electric
Currents.
I, GISBERT KAPP, of 31 Parliament Street, Westminster in the County of
Middlesex, Electrical Engineer, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to the method of and means for the distribution of electric
currents by the "sub-station system" in which high pressure currents are supplied
from the central station to a transformer or transformers placed at a sub-station or
at sub-stations in the district to be served, the low pressure or secondary circuits of
the transformer or transformers being connected in parallel with the distributing
mains, and the primary or high pressure mains (hereinafter called the "feeders")
being connected at the central station in parallel by means of omnibus bars or
omnibus terminals, as is well understood. It is well known that this system of
distribution as at present carried out has a low efficiency during those hours of the
day in which the demand for current is small, the cause of this low efficiency being
the waste of power which is proceeding at all times whether the transformers be
lightly or heavily loaded. To reduce this waste of power it is necessary to dis-
connect from the feeders and from the distributing circuits, (i.e. from the primary
and from the secondary) such transformer or transformers as may at any time be
too lightly loaded, the service in the distributing mains being supplied by the
transformer or transformers which are left in circuit. As the demand increases, as
many of the previously idle transformers are connected up as may be required.
I provide, according to my present invention, methods of and means for cutting
the transformers out of and putting them into action from the central station, and
for ascertaining at that station whether any particular transformer at any sub-
station is or is not connected with the feeders and distributing circuits. My
improvements are applicable both to continuous and to alternate current distribution,
but I will hereinafter limit my description to the alternate current system, since
the modification which may be required for the continuous system are of a very
obvious nature. The accompanying diagrams are intended to make this description
clearer and are hereinafter referred to.
I will first describe my invention as applied in an installation where several
transformers, to be separately controlled, are connected to a single feeder, or are

page_text: served by a network of feeding mains. In this case, which is diagrammatically
illustrated by Figure 1, I arrange in combination with each of the transformers to
he controlled, a compound switch ps which is capable of controlling its primary
connections with the feeders and its secondary connections with the distributing
mains. The primary element of the compound switch p is of the single or of the
double pole type. The two elements of the switch are mechanically connected, but
in order to avoid undue sparking, the contacts are arranged in such a manner that
the feeders (primary) circuit is broken before the secondary. The compound
switch is operated by an electro-motor M, through suitable gearing or devices in
such a manner as to produce a quick make or break after the lapse of a seusible
interval of time from the starting of the motor.
A B are the omnibus bars or terminals at the central station, and a bare the
feeder wires respectively connected therewith. At the sub-station the single pole
clement p of the compound switch is inserted between the a feeder wire and the
terminal of the transformer T, the other terminal of the transformer being
connected directly with the feeder wire. One terminal of the motor M, is
connected on the transformer side to the primary element of the compound
switch, whilst the other motor terminal is connected with the insulated wire m, of
small section, which is taken back to the central station along with the feeder.
This small insulated wire I call the "motor wire" and it is connected at the
central station with a suitable double contact switch m¹ by means of which it may
be connected with either of the two omnibus bars or terminals A B. Au
amperemeter may be included in the motor circuit at the central station for the
purpose hereinafter described. If the transformer be in circuit and it be desired
to cut it out, I join the the motor wire m with the 13 omnibus bar, whereupon the
motor will be energised by a current taking a course out of the a feeder through
the primary element p of the compound switch at the sub-station, through the
notor M, and back through the motor wire m to the B omnibus bar or terminal, or
the reverse. The circuit is closed for this purpose by joining the switch m' to the
contact o. When the motor has made a certain number of revolutions more or less,
the sub-station switch snaps off, and cuts out the transformer, at the same time
opening the motor circuit and consequently stopping the motor. If on the
contrary the transformer be out of circuit and it be desired to join it in, the motor
wire is connected through the switch m' and the contact i, with the A omnibus bar
or terminal, whereupon a circuit will be closed through the motor wire m, the
motor M, the primary of the transformer T, and the b feeder. The motor is then
put thereby into action and closes the compound switch p s. After the switch has
been closed, the difference of potential between the two motor terminals is only
that due to the ohmic resistance of one feeder wire, and the motor current is
instantly reduced to a very small fraction of its previous amount and the motor
stops. The moment when the compound switch ps at the sub-station is either
opened or closed is indicated on the amperemeter 1, intercalated in the circuit m,
by a sudden drop in the current. Consequently by watching the amperemeter, and
tentatively joining the motor wire with either of the omnibus bars, it is possible at
any moment to ascertain whether or not the transformer is in circuit.
The diagram Figure 2 illustrates a case in which each transformer is supplied by
a separate feeder. In such a case, the methods and appliances hereinbefore
described may if desired, be suitably employed, but I insert a double pole switch d
into the feeder at the central station, and connect the two terminals of the motor
wire switch m¹ not with the omnibus bars, but with the corresponding feeder wires ab,
on the other side of the switch d. The advantage of this arrangement is that when
taking the transformer off, the feeder current may be broken at the central station
before switching the motor on, so that the primary element of the compound
switch at the sub-station interrupts only the motor current, whilst the secondary
elements of the switch interrupts an eqrivalent amount of the low pressure current,
the power for working the motor being in this case derived from the distributing
mains. To put the transformer into circuit again, the central station double pole

page_text: •
as hereinbefore described.
is wise closed, and then the motor switch, the action of the apparatus being
In a modification of my improvements, illustrated by Figure 3, I may omit the
primary element of the compound switch at the sub-station, so that the motor M
will control only the low pressure or secondary circuit through s. In this case the
feeder current is controlled at the central station by a double pole switch d and the
motor switch m¹ has only a single contact for making connection with the b feeder
wire, in which wire or circuit the amperemeter I is inserted. To cut off the
transformer, the feeder is first switched off the omnibus bars and the motor is then
switched on. The power for working the motor is derived from the distributing
mains and as soon as the secondary switch has been opened by the motor, the supply
of power is cut off and the motor stops. To put the transformer in again, the
feeder is first switched on and then the motor switch whilst watching the ampere-
meter. The moment the secondary circuit at the sub-station has been closed,
the needle of the amperemeter gives a jerk, when the motor is switched off and
stopped.
In a further modification, illustrated by Figure 4, I employ single pole switches
at the central station end of the feeder and a double contact motor switch m¹ the
two contacts being connected to the B bar and the the feeder respectively on the
other side of the switch. To cut out the transformer, I proceed as hereinbefore
described with reference to the modification illustrated by Figure 3 of the
diagrams, putting the motor switch in connection with the contact o To put in the
transformer, I first close the switch of the a feeder, and then join the motor switch
to the B bar through contact i. At the central station a voltmeter V is connected
across the feeder wires. By watching this voltmeter it will be seen that at first no
pressure is indicated, but as soon as the secondary switch s at the sub-station has
been closed, pressure is produced at the primary terminals of the transformer, and
this is indicated by the voltmeter. The motor switch is then taken off and the
switch of the feeder is put on, which completes the operation.
The motors employed at the sub-station may be self starting single phase
alternate current motors and may be suitably wound to be operated at the pressure
at which the feeders are supplied or they may be wound for a lower pressure, in
which case I insert a suitable resistance in the motor circuit or employ a small
transformer to suitably reduce the pressure. I desire it to be understood however
that I do not make any claim to any particular type of motor or switch gear.
aware that it has already been proposed to cut in and cut out transformers at
sub-stations from a central station by different methods and means to those herein-
before described and I do not therefore make any broad or general claim to such
methods and means but only as hereinafter set forth.
I am
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
1. In a system of electric distribution, a single motor wire in combination with
one of the feeders forming an electric circuit for operating a quick make and break
switch by means of a motor, at the sub-station, substantially as and for the purpose
hereinbefore described and as illustrated by the accompanying diagrams.
2. In a system of electric distribution, the combination of connections and switches,
and a motor for cutting a transformer into and out of circuit, whereby the power
required for cutting out a transformer at a sub-station is derived from the trans-
former itself, and that for cutting it in is derived from the omnibus bars or terminals
at the central station, substantially as hereinbefore described and as illustrated by
the accompanying diagrams.
3. In a system of electric distribution, the combination of connections switches
and instruments by means of which it is possible to ascertain at the central station
whether a transformer at a sub-station is in or out of circuit, substantially as herein-
before described and as illustrated by the accompanying diagrams.

page_text: 4. In a system of electric distribution, the use of one of the feeder wires for the
purpose of completing an electric circuit for operating a motor and quick make and
break switches at a sub-station, substantially as hereinbefore described and as
illustrated by the accompanying diagrams.
Dated this 10th dor of April AD 1802
WILLIAM E. HEYS,
Agent for the Applicant.