Portsmouth: 1894
ARC LIGHTING RECTIFIERS‑
SLOW-SPEED ALTERNATORS—SWITCHGEAR
The plant of The Corporation of Portsmouth's Electric Light Installation was in a number of respects novel and original, and the official opening on 6 June reflected justifiable civic pride. At this time, the Battle of the Systems—the fierce controversy between the advocates of low-tension direct current and high-tension alternating current—was still continuing, but the Electric Lighting Committee acting on the advice of Professor Garnett, Principal of Durham College of Technical Education, had courageously decided on the use of alternating current.
ARC LIGHTING RECTIFIERS‑
SLOW-SPEED ALTERNATORS—SWITCHGEAR
The plant of The Corporation of Portsmouth's Electric Light Installation was in a number of respects novel and original, and the official opening on 6 June reflected justifiable civic pride. At this time, the Battle of the Systems—the fierce controversy between the advocates of low-tension direct current and high-tension alternating current—was still continuing, but the Electric Lighting Committee acting on the advice of Professor Garnett, Principal of Durham College of Technical Education, had courageously decided on the use of alternating current.
Arc lighting by rectified alternating current
Arc lighting had been shown by experience to be more efficient when direct current, rather than alternating current, was employed. Up to this time there had been no satisfactory form of rectifier which would allow the use of rectified alternating current.
An account of the new system of lighting adopted at Portsmouth was given in the brochure issued for the official opening: 'All the principal streets are lighted by electricity and the arrangements both in producing the current for the public lighting and using it are novel. Heretofore, where the public lighting is provided in addition to the private lighting, an entirely separate plant adapted for running the arc lamps in series is used for the production of the current, the plant generally consisting of three or four sets of engines of comparatively small power running high-tension continuous-current machines. The disadvantages of this arrangement are that during the greater number of the hours of darkness the private lighting plant is running with practically no load upon it and, therefore, at a greater disadvantage than would be the case if the public lighting were effected from the same source. Mr. Ferranti being able to satisfy the engineers that he had produced a practical motor commutator commutating alternating currents into direct ones, it was settled by the Committee to adopt this method of supplying current to the arc lamps, and to thus keep a load on the private lighting system all night long.'
The rectifier equipment was described by W. E. Warrilow in Fieldens' Magazine: 'four units with their attendant switch-gear were laid down. . . . Each rectifier consisted of a synchronous motor having two commutators, and a constant current transformer.... [The transformer] consisted of fixed primary coils, and secondary coils capable of adjustment by means of a link motion terminating in a lever provided with a sliding weight. When under current, the coils tended to move apart by repulsion, and their distance could be regulated by the adjustment of the weight on the lever. The arrangement could thus supply a constant current at a varying voltage to the series of arc circuits'.
The rectifiers played an important part in extending the use of alternating current, for the electricity supply at Portsmouth was a great success, and the brilliant lighting in the streets and shops was eulogised in the press.
Arc lighting had been shown by experience to be more efficient when direct current, rather than alternating current, was employed. Up to this time there had been no satisfactory form of rectifier which would allow the use of rectified alternating current.
An account of the new system of lighting adopted at Portsmouth was given in the brochure issued for the official opening: 'All the principal streets are lighted by electricity and the arrangements both in producing the current for the public lighting and using it are novel. Heretofore, where the public lighting is provided in addition to the private lighting, an entirely separate plant adapted for running the arc lamps in series is used for the production of the current, the plant generally consisting of three or four sets of engines of comparatively small power running high-tension continuous-current machines. The disadvantages of this arrangement are that during the greater number of the hours of darkness the private lighting plant is running with practically no load upon it and, therefore, at a greater disadvantage than would be the case if the public lighting were effected from the same source. Mr. Ferranti being able to satisfy the engineers that he had produced a practical motor commutator commutating alternating currents into direct ones, it was settled by the Committee to adopt this method of supplying current to the arc lamps, and to thus keep a load on the private lighting system all night long.'
The rectifier equipment was described by W. E. Warrilow in Fieldens' Magazine: 'four units with their attendant switch-gear were laid down. . . . Each rectifier consisted of a synchronous motor having two commutators, and a constant current transformer.... [The transformer] consisted of fixed primary coils, and secondary coils capable of adjustment by means of a link motion terminating in a lever provided with a sliding weight. When under current, the coils tended to move apart by repulsion, and their distance could be regulated by the adjustment of the weight on the lever. The arrangement could thus supply a constant current at a varying voltage to the series of arc circuits'.
The rectifiers played an important part in extending the use of alternating current, for the electricity supply at Portsmouth was a great success, and the brilliant lighting in the streets and shops was eulogised in the press.
Alternators
By this time Ferranti had an established reputation, and had successfully equipped many stations in this country and abroad, for example: Rochester, Glasgow, La Plata and Rosario (Argentine), Barcelona, Paris, Nancy, Le Havre, Melun, Troyes, Nimes, Dijon, Sens, St. Cere, and Caen. For the Portsmouth installation he supplied two machines which were the slowest-speed direct-coupled alternators in the country. The 2,000 volt alternators ran at 96 r.p.m. and although rated at 212kW according to contract, were capable of delivering 300kW each with safety.
The Committee determined to have in addition a Parsons turbo-alternator of 150kW, 3,000 r.p.m. for comparative trial, and this was erected side by side with the slow-speed alternators.
By this time Ferranti had an established reputation, and had successfully equipped many stations in this country and abroad, for example: Rochester, Glasgow, La Plata and Rosario (Argentine), Barcelona, Paris, Nancy, Le Havre, Melun, Troyes, Nimes, Dijon, Sens, St. Cere, and Caen. For the Portsmouth installation he supplied two machines which were the slowest-speed direct-coupled alternators in the country. The 2,000 volt alternators ran at 96 r.p.m. and although rated at 212kW according to contract, were capable of delivering 300kW each with safety.
The Committee determined to have in addition a Parsons turbo-alternator of 150kW, 3,000 r.p.m. for comparative trial, and this was erected side by side with the slow-speed alternators.