Year: 1885

page_text: I SEBASTIAN ZIANI DE FERRANTI of St. Benet Chambers Fenchurch Street in
the City of London Electrician do hereby declare the nature of this invention to
be as follows:-
In the distribution of electrical energy for electric lighting or it might be motive
power purposes, I lay insulated mains in squares over the district to be lighted to
distribute current to the lamps each square to feed say for example 1,000 lamps
and I provide means for coupling the conductors of each square to the secondary
coils of several convertors.
The number of convertors so coupled to the conductors of any one of the squares
may be made to depend on the current that is being used-the convertors being
switched on and off automatically or otherwise as required.
I feed the primary coils of the convertor with high tension currents from the
generating station. Convertors might also be used at the generating station to
raise the electro motive force of the dynamo to the point required for economical
distribution.
The mains for conveying the current I form of concentric tubes drawn one over
the other with insulating material between them.
For connecting the end of the inner conductor of one length to the end of the
inner conductor of the next length I use a short tube coned at each end and made
corresponding conical surfaces at the ends of the conductors to abut against these
coned ends-the hole through this short tube I make of smaller diameter than the
hole through the inner conductor so that any decrease of conducting power at the
joint owing to imperfect contact of the abutting ends is made up for by increased
sectional area in the short tube.
The ends of the outer tubes I couple together by right and left handed screw
unions or by the flanges and bolts and nuts.
For right angled or other bends I couple the end of the inner conductor of one
ength to the inner conductor of another by forcing them over the ends of a short
ube formed with the required bend in it the ends of the outer conductors I similarly
couple by forcing them into the ends of a short bent metallic tube I also provide
xpansion joints at intervals formed by forcing the ends of the inner conductors
ver the ends of a short metallic tube and coupling the ends of the outer conductors
y a flexible diaphragm joint. Means are also provided for making all external
oints watertight.

page_text: In some cases I enclose my conductors in iron in other cases I make my outer
conductor of iron.
In cases where the joints are simple and not expansion I also fill up the
space between the conductor in the joint by forcing some liquid or partially liquid
insulating material between them through a small hole and so effectually prevent
the entry of water.
Insulated conductors for conveying high tension currents to the convertors may
be carried through the interior of such tubular conductors and the circuits through
the secondary coils of these converters completed through the outer tube and
through the earth. The high tension circuit might also be completed through an
outer tube containing the conductors.
My concentric conductors may also advantageously be used as overhead suspended
wires as the currents passing in telephone wires in proximity to them would
practically not be affected. Such conductors may either support themselves
between the supporting poles or may be slung from a steel supporting wire.
In place of the conductors being concentric they may be coupled together side
by side either straight or twisted-in either case they may be encased or stranded
with iron.
A convenient way of suspending the conductors from a steel wire is to enclose
both the steel wire and the conductors in a woven or other fibrous pipe.
In order to detect leakage in any of the mains I provide means for automatically
putting first one and then the other of the conductors of the high tension main to
earth from time to time say at intervals of an hour.
If a leakage occurs in any branch distributing main the circuit of which is
completed through earth as above explained the high tension current will be short
circuited through the converter which feeds that branch main whenever one or
In the branch
other of the insulated high tension conductors is put to earth
wires passing from the main high tension conductors to the primary coils of the
converters I place fusible plugs so that the instant the current is short circuited
through any converter the fusible plugs in the wires leading to that converter will
be instantly fused and the converter and branch so put out of action.
In cases where only one of the high tension conductors is insulated and the
other in connection with earth no fault detecting apparatus would be required as
the fusible plugs leading to any branch in which a fault occurred would be fused
immediately on the leakage taking place.
In order to continuously shew and photographically record the condition of the
circuit through the high tension main I use two electrometers one coupled to
one conductor and to earth and the other coupled to the other conductor and
to earth.
The electrometers are placed side by side.
When the electrometers show that the electro-motive force in one conductor is
the same as the electro motive force in the other conductor the line is in proper
condition but any variation indicates leakage.
On the suspending cord or axis of the swinging portion of the electrometer
I mount a small mirror to reflect a narrow line of light across a long narrow sli
behind which photographic paper is made to travel
The line of light overlapping the edges of the slit is visible in juxta position to
a scale marked upon them whilst the light passing through the slit falls on the
slowly travelling prepared paper and so records upon it the electro motive force
indicated by the electrometer.
In order to give instant notice of any change of electro motive force in any on
or other of the conductors I also mount upon the cord or axis of the swinging
portion of the electrometer a balanced pair of arms-one carrying at its end a wir
which by the turning of the cord or axis will be brought in succession opposite t
the ends of two wires and in such close proximity to them as to allow of th
passage of a high tension electrical current and thereby cause a bell to be rung
Each electrometer may be provided with two bells-one to be sounded in the abov

page_text: manner when the electro motive force rises the other of a different note when it
falls and might be made to exhibit a red or green light or other signal.
In order to regulate the electro motive force I use a regulator of the kind known
as Sir W. Thompson's in which a fine wire of German silver is connected with the
two terminals of the dynamo. Any variation of the electro motive force varies
the current passing through the wire and correspondingly changes its length by
heating it more or less-and the expansion or contraction of the wire is made to
work apparatus for regulating the current.
When dealing with high electro motive force it is difficult and inconvnient to use
regulating apparatus of this kind on account of the extreme length of wire which
must necessarily be used.
To obviate this I use the regulator in conjunction with an induction coil or
electric converter so as to change the tension of the current passed through the
wire and lower it to any desired amount so that a shorter and thicker wire may
be used.

page_text: I SEBASTIAN ZIANI DE FERRANTI of St. Benet Chambers Fenchurch Street in
the City of London Electrician 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:-
In the distribution of electrical energy for electric lighting or it might be motive
power purposes, I lay insulated mains in squares over the district to be lighted to
distribute current to the lamps-each square to feed say for example 1000 lamps.
and I provide means for coupling.the conductors of each square to the secondary
coils of several converters.
The number of converters so coupled to the conductors of any one of the squares
may be made to depend on the current that is being used-the converters being
switched on and off automatically or otherwise as required.
I feed the primary coils of the converter with high tension currents from the
generating station. Converters might also be used at the generating station to
raise the electro motive force of the dynamo to the point required for economical
distribution.
I prefer however to employ dynamos at the generating station which are adapted
to maintain the requisite alternating high tension say for example 2400 volts
between the electric mains.
Figure 1 of the annexed drawings illustrates the foregoing description; a shows
the dynamo and a¹ a³ are the high tension mains proceeding from it to the various
squares into which the district is divided. 61 62 63 64 are the converters provided
for the supply of one of these squares at comparatively low tension (say 100 volts).
These converters are induction coils with primary and secondary windings prefer-
abiy they are such as are described in my Specification No. 15141 in the year 1885.
The winding of the converter is arranged to bring about the required reduction in
tension; thus the primary winding may have 24 times more convolutions then the
secondary winding whilst the weight of metál in the two windings is approxi-
mately equal. The primary winding of the converter b¹ is always connected with
the maius a a² by the branches c¹ c¹ but the converters 6 6 6 are only coupled
when required. d. d. represent the lamp circuits and d¹ d¹ the lamps in these
circuits. e¹e are the low tension mains on which lamp circuits are coupled. The
secondary or thick winding of the converter b¹ always connects the mains el es
through the branches f¹ f¹, but the converters 62 63 64 are only coupled with the
mains ele when required. The current passing from the converter 61 to the lamp
circuits d. d. traverses the coils of electro magnets g' g³ g³. The magnets have
armatures which are held off by springs of different tensions. When the quantity
passing reaches the maximum which the converter 61 is intended to supply the
magnet gl attracts its armature and moves switches h³, and by which the primary
circuit of the converter 6 is closed through the branches c c and its secondary
circuit through the branches f' f'..
Similar when they are required the converters 63, and 6* are successively brought
into operation.

page_text: Again when the current through the magnets g¹ g³ g³ decreases in consequence of
lamps being put out of circuit the armatures in succession fall away from the
magnets and the converters 6 683 and 6ª are successively disconnected.
By the means above described I avoid the loss which is involved in the employ-
ment during the time of minimum consumption of more convertors or larger
convertors than is required to meet the demand and at the same time I ensure that
the convertor which supplies the minimum consumption shall not be over burdened
when an increased demand comes on.
The mains for conveying the current I form of concentric tubes drawn one over
the other with insulating material between them.
For connecting the end of the inner conductor of one length to the end of the
inner conductor of the next length I use a short tube coned at each end and make
corresponding conical surfaces at the ends of the conductors to abut against these
coned ends. The hole through this short tube I make of smaller diameter than
the hole through the inner conductor so that any decrease of conducting power at
the joint owing to imperfect contact of the abutting ends is made up for by
increased sectional area in the short tube.
The ends of the outer tubes I couple together by right and left handed screw
unions or by flanges and bolts and nuts.
For right angled or other bends I couple the end of the inner conductor of one
length to the inner conductor of another by forcing them over the ends of a short
tube formed with the required bend in it. The ends of the outer conductors
I similarly couple by forcing them into the ends of a short bent metallic tube.
I also provide expansion joints at intervals formed by forcing the ends of the inner
conductors over the ends of a short metallio tube and coupling the ends of the
outer conductors by a flexible diaphragm joint. Means are also provided for
making all external joints watertight.
In some cases I enclose my conductors in iron-in other cases I make my outer
conductor of iron.
the space
In cases where the joints are simple and not expansion I also fill up
between the conductor in the joint by forcing some liquid or partially liquid
insulating material between them through a small hole and so effectually prevent
the entry of water.
Insulated conductors for conveying high tension currents to the converters may
be carried through the interior of such tubular conductors and the circuits through
the secondary coils of these converters completed through the outer tube and
through the earth. The high tension circuit might also be completed through an
outer tube containing the conductors.
My concentric conductors may also advantageously be used as overhead suspended
wires as the currents passing in telephone wires in proximity to them would prac-
tically not be affected. Such conductors may either support themselves between
the supporting poles or may be slung from a steel supporting wire.
Figure 2 is a longitudinal section of an electric main as I prefer to construct it.
k is an interior tubular conductor. is insulating material lapped around it and
consisting it may be of paper saturated with shellac in solution, m is the exterior
tubular conductor, it is preferably drawn down upon the insulating material so as
to render it impossible for moisture to enter between. The conductor k and m
form part of one circuit; the conductor k may be called the negative conductor
and m the positive although this is not strictly accurate for the currents which
I employ alternate.
Figure 3 is a longitudinal section of a joint in the electric main. n is a short
doubly coned tube inserted between the ends of the tubes k. k. which are adapted
to fit it. o is a socket with right and left hand threads within it adapted to fit the
ends of the tubes m. m. which have similar threads upon them.
By screwing up the socket o the tubes k and n are made to butt very firmly
ogether and good electric contact is established over the large surfaces provided
by the tapering of the tube n and by the screw thread on the socket o. o¹ is a

page_text: plug in the side of the socket o.
When the joint is screwed up a semi solid
insulating material is forced in through the plug hole by a force pump so as to fill
every cavity and exclude moisture. A soft or softened paraffin will be found
suitable. By screwing in the plug o¹ further pressure is put on to the filling
material to drive it completely home.
Figure 4 is a longitudinal section through a right angle joint. The tubes k. k.
are driven by heavy pressure over the ends of the angle tube p and sockets are
screwed on to the conductors m. The sockets are then bolted or rivetted together
and filled as described with semi solid insulating material.
q
Figure 5 shows an expansion joint. The conductors k. k. are driven by pressure
on to the ends of the tube g and metal discs r. r. are secured to the conductors m. m.
These discs are caused to abut upon a ring 8. and are secured to it by rivets or
bolts as the figure indicates.
In place of the conductors being concentric they may be coupled together side
by side either straight or twisted-in either case they may be encased or stranded
with iron.
A convenient way of suspending the conductors from a steel wire is to enclose
both the steel wire and the conductors in a woven or other fibrous pipe.
Figure 6 shows the way in which I apply fuses or cut outs to prevent an undue
amount of energy being developed in any converter and to prevent loss by
leakage.
a a are the high tension mains they are connected by branches c¹ c¹ and c³ o³
with converters b₁ 6 which in this case are represented as in connection with
separate lamp circuits dd. t. t. are fuses which I introduce into the branches c¹ c¹,
cthey are copper wires so proportioned that if an undue amount of enèrgy is
-exerted through them they at once become heated and break or burn away.
Now I have discovered that in an arrangement such as that shown where the
conductors of a high tension circuit are connected through fuses with the primary
conductors of electric converters, and where the secondary conductors of the electric
converters are connected with low tension circuits that if by any accident a short
circuit is established through the secondary conductor the fuse in the high tension
branch although in a different circuit is immediately destroyed and the apparatus
disconnected. But for this provision so much energy would be developed that the
apparatus would be destroyed and there might be risk of injury to other property.
In place of a fuse it is possible to employ other apparatus which operates to
open the high pressure branch when too much energy is being exerted in it and in
the corresponding low pressure circuit. Thus an electro magnet may be provided
in the high pressure circuit with an armature which is normally held off by a
spring but when undue energy is developed is attracted and in moving opens the
high pressure branch circuit.
The method is substantially the same whatever may be the nature of the
automatic cut out employed and consists in placing a fuse or an automatic cut out
where under the conditions indicated it will be influenced and caused to operate by
a short circuiting occurring in a circuit with which it has no metallic conductive
connection.
Figure 7 is a plan and Figure 8 a portion of a side view of the fuse apparatus as
I prefer to construct it. t. t. are the fuses they are connected with coiled springs
and the springs are made to engage with hooks at the opposite extremities of
rollers of insulating material. When one fuse breaks the other at once escapes
from its retaining hooks and so the circuit is opened in both brauches.
Figure 9 shows the arrangement where concentric mains are employed, some-
times one of the mains of the high tension circuit is uninsulated. a¹ a¹ are
concentric mains. c¹ c¹ are branches leading to converters 61 and 6' they also may
consist of concentric tubes the outer one uninsulated t. t. are the fuses d. d. are
the lamp circuits.
With arrangements as shown by Figure 6 in order to detect leakage I provide
means for automatically putting first one and then the other of the conductors of

page_text: the high tension main to earth from time to time; then if leakage occurs in any
branch distributing main c¹ c³ the fuse or cut out will be brought into operation.
In cases where only one of the bigh tension conductors is insulated and the
other in connection with earth no fault detecting apparatus would be required as
the fusible plugs leading to any branch in which a fault occurred would be fused
immediately on the leakage taking place.
In order to continuously show and photographically record the condition of the
circuit through the high tension main I use two electrometers one coupled to one
conductor and to earth and the other coupled to the other conductor and to earth.
The electrometers are placed side by side.
When the electrometers show that the electro motive force in one conductor
is the same as the electro motive force in the other conductor the line is in proper
condition but any variation indicates leakage.
Figure 10 illustrates this arrangement. a, is the dynamo. a¹ a² are the high
tension mains. b. b are converters. cc branches provided with fuses t. t.
d. d. lamp circuits. represent two electrometers coupled as described. vis
an earth plate connected with one of the parts of each electrometer the remaining
parts being connected as described with the terminals of the dynamo or the
mains a¹ a windicates an accidental earth; as will be seen it in effect shunts
one of the electrometers.
On the suspending cord or axis of the swinging portion of the electrometer
I mount a small mirror to reflect a narrow line of light across a long narrow slit
behind which photographic paper is made to travel.
The line of light overlapping the edges of the slit is visible in juxta position to
a scale marked upon them whilst the light passing through the slit falls on the
slowly travelling prepared paper and so records upon it the electro motive force
indicated by the electrometer.
In order to give instant notice of any change of electro motive force in any one
or other of the conductors I also mount upon the cord or axis of the swinging
portion of the electrometer a balanced pair of arms one carrying at its end a wire
which by the turning of the cord or axis will be brought in succession opposite to
the ends of two wires and in such close proximity to them as to allow of the
passage of a high tension electrical current and thereby cause a bell to be rung.
Each electrometer may be provided with two bells--one to be sounded in the
above manner when the electro motive force rises the other of a different note
when it falls and might be made to exhibit a red or green light or other signal.
In order to regulate the electro motive force I use a regulator of the kind
known as Sir W. Thomson's in which a fine wire of German silver is connected
with the two terminals of the dynamo. Any variation of the electro motive force
varies the current passing through the wire and correspondingly changes its length
by heating it more or less and the expansion or contraction of the wire is made to
work apparatus for regulating the current.
When dealing with high electro motive force it is difficult and inconvenient to
use regulating apparatus of this kind on account of the extreme length of wire
which must necessarily be used.
To obviate this I use the regulator in conjunction with an induction coil
or electric converter so as to change the tension of the current passed through the
wire and lower it to any desired amount so that a shorter and thicker wire may
be used.
In the case which I have previously taken by way of example of the use of a
high tension of 2400 volts I employ a small converter wound about one to one
hundred for the relative lengths of secondary and primary,
I connect the fine primary winding with the dynamo and the short and thick
secondary winding I bring to terminals, between which a potential of 24 volts is
thus maintained. With these terminals I connect the German silver wire and
I apply the varying expansion of this wire, with the heat of the current, to control
regulating apparatus in any of the well known ways; for example it may open

page_text: 4
and close a relay circuit in which is an electro magnet or solenoid operating the
valve of an hydraulic governor in connection with the engine by which the dynamo
is driven.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The improved means for distributing electric energy consisting in providing
high tension mains and low tension mains, and causing each low tension main to
be fed from the high tension main through two or more convertors which are
connected and disconnected as required.
2. The combination of electric circuits and apparatus substantially as described
in respect to Figure 1 of the annexed drawings.
3. An electric main consisting of two metallic tubes drawn one over the other
with insulating material between forming part of the same circuit and maintained
at a suitable difference of electric potential.
4. The methods substantially as described for forming joints in electric mains.
5. The combination with a system consisting of a high pressure circuit, feeding
low pressure circuits by the aid of electric convertors connected by branches with
the high pressure circuit; of fuses or automatic cut out apparatus in the said
branches operating to open the branch circuit when short circuiting occurs.
6. The combination of a high tension circuit, convertor, low pressure circuit
and fuse in the high tension circuit, substantially as described.
7. The application of fuses in combination with high and low tension circuits
and convertors substantially as described in respect to Figures 6, 7, 8 and 9.
8. The combination of the dynamo a producing alternating currents, the
electric mains a¹ a*; the two electrometers uu and the earth connection v; the
whole forming an arrangement in which accurate indication of any leakage in
the mains is obtained.
9. The combination of a dynamo producing alternating currents, a convertor
connected with the primary of the dynamo, a wire in the secondary circuit of the
convertor expanding and contracting with the variations of the current therein
and operating to correct any variation from the normal condition substantially as
described.
10. My improvements substantially as described in the meaus for distributing
electric energy.