Standard 210 instrument and control switches are used in conjunction with circuit breakers, transformer tap changers, motor-operated rheostats, and many other types of electrically-controlled apparatus. The switches are available as either maintained or spring return contact types. They’re designed for panel mounting and are furnished with a choice of handles.
All type 210 switches are made for partial for full 360 degree rotation, with 2 to 12 radial positions. The spring return switches are made for three positions, but they can be furnished for a maximum of seven positions – three from either side of the center position.
On circuit breaker control switches, there’s a window in the position place with a red and green flag indicator to show the last operation of the switch. A signal lamp circuit is available as an option. In the trip position, it can be opened by pulling the handle into the latch position. The lamp is not lighted when the handle is in this position, indicating that the circuit controlled by the breaker is not in use. The flag indicator and pull-out features aren’t usually furnished on switches for voltage control, speed control or motor control.
Positive Positioning Assured
Even under the most severe operating conditions, Type 210 rotary switches will give you reliable service. They feature a positive positioning device with a star-shaped position wheel, two roller arm assemblies and two tension springs. The peaks around the position wheel virtually eliminate any hang-up area. This, combined with the push-pull effect of the roller, make in-between positioning impossible.
Since there’s no possibility of hang-up, arcing and burning of contacts are reduced. Since it’s impossible to overshoot or momentarily place a switch in an unsafe position, you save contact segments from undue wear. And the snap action of the positioning device gives the control board operator a definite feel of the control operation.
Tests indicate that you can expect the new positioning feature to perform reliable for more than two million operations. To minimize corrosion, we’ve treated the roller arm assemblies and positioning wheels, and used stainless steel for the springs. We’ve also provided a self-cleaning wiping action to give you good contact under all conditions. Moveable segments with star-shaped holes are used to provide extremely accurate positioning. The holes engage a square insulated shaft which moves the segments. That shaft is machined to closer-than-normal clearances, and the corners are extra sharp. This eliminates any possibility of play between parts.
Extra-long creepage over insulation surface prevents a low-resistance leakage path or flashover due to condensation or dust on the insulator surface. We’ve used insulation of heavy linen base and industry-quality phenolic throughout the switch.
All contacts are readily accessible. Simply remove the snap-on cover from either side, top or rear. The cover, provided with the switch, eliminates the need for side plates. And the terminal arrangements permits wiring without removing the switch cover.
It’s an easy matter to replace contacts or add stages for special applications. Each pair of stationary contact fingers is mounted on an individually-molded phenolic block.
The switch can be mounted quickly on a panel, and secured with three mounting screws.
The Test of Time
Under the most extreme and adverse operating conditions, the Standard 210 switch has proved its reliability. Time and time again.
Components & Quality Construction
Handles – Made of block molded composition, handles are available in oval, round and pistol-grip shapes. For a slightly higher price, you may choose colored handles in blue, brown, grey, green, red, white and yellow. Instrument switches are normally furnished with round handles. Voltage, motor and speed control switches come with oval handles, and circuit breaker control switches come with pistol-grip handles.
To prevent operation by unauthorized people or simultaneous operation of more than one switch controlling the same circuit, you may order removable handles with a key shaft. These handles can be used with all instrument switches, although ammeter, regulator, transfer and temperature indicator switches are not normally key operated.
Switches for synchronizing two machines require a removable handle for each machine.
Handles can be turned only in one direction. Removable handles are labeled and constructed so that they can be inserted only in the proper switch or switches – and then only in the “off” position.
Locks – A lock can be mounted directly above the position plate of the switch. The switch can be arranged to lock only in selected positions.
Position Plate – In addition to listed switches with proper titles and markings, position plates requiring special titles and markings can be supplied.
Face Dial Plate – The black position plate, with inscription, is held in slots of the face plate. In addition, the face plate serves as a holder for the flag indicator on control switches.
Shaft – A 3/8 inch square, cold-rolled steel shaft is insulated with a covering of linen-base phenolic tubing.
Cover – The black protective covering is made of laminated phenolic. This formed, snap-on cover is heat resistant and will retain its springiness. It is easily removed from the top, from either slide, or by sliding off to the rear.
Contact Fingers – Heavy phosphor bronze contact fingers are silver plated for long wear. The contact pressure is about 12 ounces.
End Plates – Both end plates are 7/32-inch thick. They are made of die cast aluminum to prevent corrosion.