Figs. 2,199 and 2,200.—General Electric triple pole solenoid operated, single throw remote control switch, and push button switch for operating same. Switch is a self-contained unit with two sets of contacts, main laminated copper brushes, and carbon auxiliary contacts to take the arc on breaking the circuit. The main brushes are so made that each lamination makes an end on contact with the switch blade without any tendency to force the laminations apart. A wiping effect, given to the contacts every time the switch is closed, keeps the contact surfaces clean and insures good contact at all times. The carbon auxiliary contacts are made of blocks of carbon fastened without screws. In operation, the switch is actuated by a double coil solenoid, one coil for closing and one for opening, controlled by the single pole double throw push button switch shown in fig. 2,200, which is normally in the open position and remains closed only when held by the operator. One of these switches is furnished with each control switch and must always be used, as the solenoid coils are not intended for continuous service. The power required to operate the remote control switch is small, being approximately 1.6 amperes at 110 volts, 0.81 amperes at 220 volts direct current, and 10 amperes at 110 volts, and 6 amperes at 220 volts alternating current 60 cycles. The main switch can be closed and opened by hand, and the push button located at any point.

Figs. 2,201 and 2,202.—Palmer service switch and fuse box, for either plug, cartridge or open link fuses. Fig. 2,201 illustrates the box in open position for the inspection of fuses, etc. The cover is held open by a simple lock so that the switch cannot fall closed by gravity, the box may be mounted so that the service wires lead directly into a sealed terminal chamber from any direction, and all current carrying parts made accessible by the opening of the switch are dead. Fig. 2,202 illustrates the device with side of box and cover cut away to show interior and the normally sealed cover of terminal chamber removed. The switch contacts do not enter their contact clips until the flanged cover of the box has closed the switch opening, no current connections being made to line or load until the box is completely closed, and in consequence there is no opportunity to make improper connections to any live parts of switch, when conduit connections are used to the service and meter wires.

Fig. 2,203 and 2,204.—Bus transfer plug switch. The method of supporting the contact farthest from the panel consists of a porcelain pillar of the same height as the receptacle, clamped to a brass connecting or bus bar which in turn is fastened to the receptacle.

Fig. 2,205.—Ammeter jack. This plug switch is insulated for high pressure and consists of two parts: the ammeter jack, and the ammeter jack plug, cable, and bushing. The receptacle, which is simple in construction, consists of a brass bushing well insulated from the panel and protected on the front of the panel by a porcelain bushing. On the end of this tube and insulated from it, is a phosphor bronze spring which, when the plug is out, rests on the brass tube and keeps the circuit closed. The plug consists of a brass rod well insulated and set in a brass tube, both being fastened in a handle which is stained black and polished. Inside the handle is run a twin conductor cable, one side being soldered in the brass tube and the other to the brass rod. The other end of the cable is run through a bushing set in the panel and thence to the ammeter or current transformer. Where it is desired to remove the plug and cable from the board, or to plug both ends of the cable in different receptacles, a plug instead of a bushing should be used. In this case a cable should be provided with a plug on each end.

Fig. 2,206.—Westinghouse fused starting switch for squirrel cage motors. It is arranged for National Electric Code fuses on one end only and has springs on the other end to open the switch automatically if left closed at this end. The corresponding terminals at both ends of the switch are connected in grooves in the back of the slate base so that the wiring need be connected to one set of these terminals only, thus decreasing the number of connections necessary, as shown in fig. 2,207. In starting an induction motor, the switch is thrown to the end that is not fused and held there until the motor is up to running speed; then it is quickly thrown to the fused position, thus protecting the circuit under running conditions.

Fig. 2,207.—Diagram of connections of Westinghouse fused starting switch for squirrel cage motors. The starting current of induction motors is several times the normal running current and, when the controlling switch is fused to carry the running load only, the fuses are apt to blow when the motor is started. The fuses must be of a capacity to prevent overloads under running conditions. These switches are designed to meet this difficulty and are used without auto-starters to control motors up to 5 horse power rating.

Fig. 2,208.—Westinghouse single pole disconnecting switch. Disconnecting switches are used primarily for isolating apparatus from the circuit for purposes of inspection and repair; also for sectionalizing feeders. They are not designed for opening under load, and therefore no attempt should be made to open them with current in the circuit. In connection with lightning arrester installations, disconnecting switches are particularly useful, providing a simple and effective means for isolating the arresters while cleaning and inspecting. The switch is opened and closed with a hook on the end of a wooden pole, which hook engages in a hole provided in the switch blade. This type of disconnecting switch is intended for wall mounting. The live parts are mounted on porcelain insulators carried on a cast iron yoke or base, forming a simple and substantial construction.

Figs. 2,209 and 2,210.—Westinghouse disconnecting switches for pressures over 3,300 volts.

Figs. 2,211 and 2,212.—Westinghouse selector type disconnecting switch. Fig. 2,211, view showing both sides closed; fig. 2,212, view with one side open. The selector type of disconnecting switch is a transfer switch which does not require the circuit to be interrupted while making the change. It can also be used to connect two independent circuits in parallel. In construction, it is in effect two single throw, single pole disconnecting switches with the hinge jaws connected together and mounted on the same insulator. The hinge jaw is also provided with dummy jaws to hold either blade of the switch in the open position. Except for these differences in the hinge jaws, the construction is similar to the switch shown in fig. 2,209. It should not be used to open the circuit when loaded.

Fig. 2,213.—Hook stick for operating a disconnecting switch.

Fig. 2,214.—Baum 35,000 volt, 200 ampere, double break pole type switch. While designed for disconnecting purposes only, it can break considerable amperage. The levers and couplings are fastened with tape pins. The control shaft coupling is adjustable to any angle, and the switch can be locked in the open or closed position. A removable wooden handle is supplied and the switch can be handled in any weather. The arms can be extended to hold fuse fittings, or dead end insulators in the event of a heavy strain, but it is preferable to have fuses on another structure as a precaution against coming in contact with the energized portion of the switch, and it is also preferable to take the strain of the line on a pole a few feet from the switch, rather than on the switch structure, particularly in the larger sizes. An insulating wood section in the control shaft separates the control handle from the remainder of the switch. Discharging horns can be fitted to this type of switch and when so equipped they have been found capable of breaking considerable loads.

Fig. 2,215.—Pacific swivel type blade for Baum pole top switches. The twist type of blade, here shown, is especially adapted to switches operating in freezing or sleety weather. It will be seen that the first few degrees through which the rotating insulator is moved have the effect of twisting the blade between the shoes of the contact, which breaks any seal through freezing, or corrosion.

Fig. 2,216.—Pacific 22,000 volt, 100 ampere, pole top switch equipped with fuse tubes; designed to meet the need for a small group controlled disconnecting switch, having several features making it suitable for use with service transformer installations and line branches. The switch is made with clamped pipe arms permitting adjustment. It is equipped with fuse tubes and fittings, but should the fuses be not desired, the arm may be shortened. Provision is made for fitting insulator pins to the top of the arms, when the switch is mounted vertically, which will hold insulators at right angles to the switch, making it possible to end a line on the top of these arms and then drop down through the switch to the bank of transformers. The switch is so constructed that gravity tends to hold it in either the open or the closed position. Provision can be made for locking.

Fig. 2,217.—Horn break switch. In operation, the arc formed at break, will travel toward the extremities of the horns because of the fact that a circuit will tend to move so as to embrace the largest possible number of lines of force set up by it. Hence, the arc that starts between the horns where they are near together rises between them until it becomes so attenuated that it is extinguished.

Fig. 2,218.—Westinghouse rear connected motor starting switch, for pressures up to 600 volts. It is used for starting rotary converters and direct current motors of large capacity having starting torque small enough to permit cutting out the starting resistance in few steps. The clips can be connected to any type of resistor, the steps of which are successively short circuited as the switch closes; the amount of resistance in the armature circuit is thus gradually reduced. A pause should be made after each step of resistance is thrown in to allow the motor speed to accelerate. If the starting switch do not have to carry the full load current and can be short circuited by another switch, a starting switch of smaller capacity equivalent to 50 per cent of running current of the machine can be used. The switch is of the single pole, single throw, rear connected, four point, knife blade type.

Fig. 2,218.—Westinghouse rear connected motor starting switch, for pressures up to 600 volts. It is used for starting rotary converters and direct current motors of large capacity having starting torque small enough to permit cutting out the starting resistance in few steps. The clips can be connected to any type of resistor, the steps of which are successively short circuited as the switch closes; the amount of resistance in the armature circuit is thus gradually reduced. A pause should be made after each step of resistance is thrown in to allow the motor speed to accelerate. If the starting switch do not have to carry the full load current and can be short circuited by another switch, a starting switch of smaller capacity equivalent to 50 per cent of running current of the machine can be used. The switch is of the single pole, single throw, rear connected, four point, knife blade type.

Fig. 2,219.—Baum disconnecting switch with horns and auxiliary contacts (Pacific Mfg. Co.). This switch is for use on systems operating at 100,000 volts or over. It has a spacing of five feet between outer insulators, is equipped with auxiliary shoes that break the circuit between the horns, diverting it from the current carrying contacts so that they are not attacked by the arc.

Fig. 2,220.—Kelman switching mechanism. The pantograph arrangement of the contact blades gives a double horizontal break deep down in the oil. This gives over the break a heavy head of oil which immediately closes in around the thin blades as they leave the contacts in opening, thus effectually extinguishing the arc. The opening spring acts within the pantograph itself without any intervening mechanism, and the light weight of the few moving parts enables the spring to accelerate the blades rapidly, thus obtaining a quick break. The contacts are of the return bend type, which makes a flexible contact, to obtain alignment with the blades at all times. The pantograph and contacts are supported on corrugated porcelain insulators on a hardwood base or insulator board. The insulators are fitted with iron ends for securing the different parts. At each end of the insulator board is an upright or lifting board which serves to lift the switching mechanism out of the tank. The leads are heavily insulated.

Fig. 2,221.—Sectional view of Pacific weatherproof oil switch for use in places exposed to the weather. All moving and contact parts are supported from the cast iron top and are readily removable for inspection or repair.

Fig. 2,222.—General Electric central station triple pole single throw oil switch; view of switch in tank. This type is for pressures up to 110,000 volts, being adapted for stations employing open wiring, since the connections are made at the top of the switch and its construction obviates the need for isolating it in a cell. One tank with two breaks in series are used for each phase.

Figs. 2,223 to 2,226.—Westinghouse indoor, two pole double throw oil switch for pressures not over 6,600 volts. Fig. 2,223, open position; fig. 2,225, closed position. This type of switch is suited for a wide range of application, being made in both switchboard and wall mounting styles; also for remote mechanical control by the use of bell cranks and connecting rods. The wall mounting style is adaptable to motor installations on account of the facility with which it may be mounted on any support, convenient to the motor operator. The lever and handle extend outward over the oil tank, so that the switch may readily be mounted against a wall, post or any vertical support. The characteristic features of this type of switch are: knife blade contacts submerged in oil; live parts carried on a porcelain base affording a permanent insulation between adjacent poles, and between the frame and live parts; compactness and accessibility; enclosure of all live metal parts; and low first cost. Each contact jaw has attached to it an arcing piece which takes the final break, thus preventing any burning of the jaws. These arcing pieces are inexpensive and readily replaced when worn or burnt away. The contact making parts are enclosed in a sheet metal oil tank which has an insulating lining. The leads are brought out at the top. Connections to the outside circuit are made inside the switch and a porcelain insulator is slipped over the joint, thus providing a straight continuous connection from the line with maximum insulation. On the 6,600 volt switch, insulation is obtained by the use of porcelain bases for supporting the live parts. In the 3,300 volt switch specially treated wooden bases are used, suitable barriers being provided between the poles where necessary to prevent arcs communicating.

Fig. 2,227.—Kelman electric control unit for oil switch. It consists of an iron frame which contains the opening and closing coils and the bearings for the operating bell crank. A small switch on the frame automatically opens the coil circuit at the end of the stroke in either direction and operates signal lamps to indicate the open or closed position. The automatic overload release opens the switch by closing the opening coil circuit. This electrical operating unit gives satisfactory service through a wide variation of voltage. It requires a momentary expenditure of energy of from 1,500 to 4,000 watts, depending on the size.

Figs. 2,228 and 2,229.—Views showing mechanism of hand operated remote control switches. Fig. 2,228, straight mechanism; fig. 2,229, angular mechanism.

Fig. 2,230.—Pacific oil switch with solenoid control, designed for 60,000 and 70,000 volt installations; it is capable of handling a 25,000 kw. generating station. The break is horizontal, made by the rotation of a flat member edgewise through the oil. The solenoid, at its extreme outer position, has a free start before commencing to move the control parts of the switch. As it approaches the extreme inner position, where the opening spring and the contacts begin to offer the greatest resistance, the magnetic action is, of course, most powerful, and the leverage by which it is applied moves to an increasing radius, by means of rollers working in the curved slots of the control shaft levers. These curved slots and rollers have the additional advantage of making the opening action very free and smooth. The tripping coil does not act on the latch directly, but gives a hammer blow that is positive. The latch proper is a roller having a powerful hold and easy release. Current can not be left on either the closing or opening coils, as they are automatically cut out by the movement of the switch.

Fig. 2,231.—Diagram of connections of motor operated remote control switch. The motor which operates the switch is controlled by a small lever generally mounted on the panel with the instruments which are in the circuit controlled by the switch. The standard pressure for operating the motors is 125 volts.

Fig. 2,232.—General Electric motor operated three phase oil switch. The operation of the oil switch is accomplished by a small hand controlling switch, generally mounted on the panel, with the instruments which are in the circuit controlled by the oil switch. The standard pressure for the operating motor is 125 volts. The switch has six breaks, each break being a separate tank. In addition to this isolation of the breaks, each phase is enclosed in a fireproof brick compartment, making it impossible for trouble in one phase to be communicated to another. The cells are constructed of brick with top and bottom slabs of slate. The capacities of such switches, range from 2,500 to 60,000 volts, and from 100 to 1,000 amperes.

Figs. 2,233 to 2,235.—Diagrams showing connections for General Electric single, double, and triple pole, solenoid operated remote control switches. The operating coils are shown connected to main switch circuit, but may be connected to an entirely separate control circuit. Connections are the same for either alternating or direct current.

Fig. 2,236.—Westinghouse three pole hand operated remote control oil switch, adapted for the control of alternating current circuits of small and moderate capacities, the pressures of which do not exceed 25,000 volts. Each unit is installed in a separate masonry compartment. The open position of contacts is maintained by gravity. Up to and including the 600 ampere capacity, the contacts are cone shaped with an arcing tip, as shown for capacities in excess of 600 amperes, brush contacts are furnished with auxiliary arcing contacts of the butt type. Each pole has two sets of contacts, thus providing a double break in each line. With both types of contact, the final break of the arc is taken and the main contacts protected by auxiliary arcing contacts which are inexpensive and readily renewable. The upper or stationary contacts are mounted on porcelain insulators secured in the soapstone base. The lower or movable contacts are carried by a wooden rod connected to and moved vertically by the operating mechanism. The operating mechanism of the hand operated breaker consists of a simple system of levers, bell cranks, and rods. The necessary energy for making a positive contact is small owing to the use of a toggle mechanism. The leads are brought out of the top of the breaker through heavy porcelain insulators. On breakers above 3,500 volts, the connections to the line wires are made by means of a union which can be tightened with a socket wrench fitting inside the insulator. As the leads coming into the switch are necessarily insulated wire or cable, this arrangement eliminates all exposed live parts and is well adapted to making connections readily to bus bars located above or in the rear of the circuit breakers.

Fig. 2,237.—Cutler-Hammer enclosed float switch, designed for the automatic control of alternating current motors operating pumps used to fill or empty tanks, sumps or other reservoirs. The switch is operated by the rise and fall of a copper float which is connected to the switch lever by a brass rod or copper chain. As the water level rises and falls, the float moves up and down. This movement is transmitted to the switch lever and the switch (if the movement be sufficient) is tripped to make or break the motor circuit. To insure the best operation it is necessary that the float rod be provided with a guide so that the float will move up or down in a vertical line, as shown. The minimum difference in water level at which the switch will operate is approximately 10 to 12 inches. When the float is placed in a closed tank, the minimum height inside from the bottom of the tank to the top should be at least 6 inches greater than the difference in water level to provide sufficient clearance for the float. When this type switch is used as a tank switch, the contacts are closed when the water level is low, putting the motor, driving the pump, in motion. When the water in the tank reaches a predetermined high level the float arm opens the switch contacts, and the motor is disconnected from the line. For sump pump purposes, the contacts open on low level and close on high level, the lever being reversed for this purpose. Two pole, three pole and four pole switches of this type are made, all arranged to completely disconnect single phase, two phase and three phase motors from their circuits. When used with small motors which may be thrown across the line to start, the switch may be used without a self starter if desired.