. Electric railways, theoretically and practically treated . be subjected. Circuit-Breaker Trip. — In case of an abnormally greatcurrent, due to a short circuit or otherwise, the deviceknown as the Circuit-Breaker Trip operates to open apair of contacts normally closed, breaking the commonnegative battery return of the magnets opening all theswitches. This safety device has proven most effective,opening the severest short circuits without damage to theswitch contacts. Line Relay. — There is also provided a device, the LineRelay, to open all unit switches should the current supplyfail. It consi
. Electric railways, theoretically and practically treated . be subjected. Circuit-Breaker Trip. — In case of an abnormally greatcurrent, due to a short circuit or otherwise, the deviceknown as the Circuit-Breaker Trip operates to open apair of contacts normally closed, breaking the commonnegative battery return of the magnets opening all theswitches. This safety device has proven most effective,opening the severest short circuits without damage to theswitch contacts. Line Relay. — There is also provided a device, the LineRelay, to open all unit switches should the current supplyfail. It consists of a magnet connected across the currentsupply mains with resistance in series, the armature ofwhich holds two contacts in the operating circuit closedagainst the tension of a spring. Operation of Unit Switch Group. — Diagram, Fig. 92,with the addition of the line switch between No. 6 switchand trolley, shows the motor and resistance connection ofall unit switches. The sequence in which these switches close is as follows : 146 ELECTRIC Fig. 93--CONTROLLER CIRCUITS UNIT SWITCH SYSTEM. Sequence. Notch No. I St, I, 2d, 2, 3d, 3, 4th, 4, 5th, S> 6th, 7th, 8th, 9th, 6, loth, 7> nth. 8, 12th, 9» TYPES OF CONTROL AND THEIR OPERATION. 147 Switches No. Line Switch, 6, 7. 6, 7, 8. 6,7,8,9-10. 6, 7, 8, 9-10, 11-3. 6, 7, 8, 9-10, n-3, 1-2 (Full Series).6, 7, 8, 9-10, 11-3, 1-2, 5. 6, 5. 6, 5, ,4-12-13. 6, 4-12-13, 9-10. 6, 4-12-13, 9-10, , 4-12-13,9-10, n-3, 1-2(Full Multiple). Operation of Low Voltage Magnet Circuits. — Refer tosketch. Fig. 93; with the master switch in the offposition, all the unit switches are open ; reverser in for-ward or back position; interlocks on i, 2, n, 6, 7,8 and 9 switches open; that on No. 10 closed, and thelong contacts closed on the high contacts of Nos. 4 and 5interlocks. Moving the master switch handle to the first positionconnects fingers 5s and either i or 2 to B-f, completingthe circuit from battery plus, thr
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkvannostrand
