We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
CH. Ill] ARC LAMPS WITH SMALL CURRENTS 89
§ 133. Turning off the small arc lamp. — The snap or key switch in the usual incandescent lamp socket is designed to break the circuit where, at most, two amperes are used. These key switches, if used to interrupt a relatively large current, like that used for the small arc lamp, are liable to start an arc within the socket. If such an arc is started, the socket will be short circuited, resulting either in the burning out of a fuse, the burning out of the socket or something more serious.
The liability of a socket to arc is much greater with direct than with alternating current. The liability to arc is also much greater if the key switch is turned slowly than when it is turned quickly.
By observing the following directions the current may be turned off with perfect safety :
(1) Turn off the current by separating the carbons until the lamp goes out, then the key switch may be used, or a plug or extension pulled apart.
(2) Turn off the current by pulling the separable plug or the separable extension apart (fig. 49-50).
(3) Make use of a knife or snap-switch (fig. 1,2, 40).
(4) Do not turn off the current by the key switch in the bulb socket. When the lamp is out, it is safe to turn the key switch in the socket.
(5) Do not unscrew a plug to turn off the light, for the break in the circuit is so slow that an arc will almost certainly be formed.
§ 134. What to do in case the key switch is used and an arc is formed in the socket:
(1) Turn the key on again as quickly as possible.
(2) If the arc lamp is still burning after turning on the key switch, turn the lamp off by method i to 3 (§ 133).
(3) Go to the nearest room switch and turn off the current.
In case a fuse is blown out — which is almost sure to occur if an arc is formed in the socket — or if the lamp socket is burned out, it is wise to call in an electrician to make the necessary repairs. This, of course, assumes that the user has not the technical knowledge necessary to make the corrections himself. It is further