Page 176 - Electromechanical Devices and Components Illustrated Sourcebook

138 Electromechanical Devices & Components Illustrated Sourcebook

Flip Lever Output Terminal High-Voltage Insulators
Terminals
Input
Terminal
On
20 AMP Body
240 VAC
Tripped
Condition Label ON
Current Rating 20 Off
Vacuum Vessel
Mounting
Socket
Inspection Ports
Figure 8-10 Power Center Circuit Breaker

Figure 8-12 240,000-Volt, 40,000-Amp Power Transmission
Circuit Breaker
terminal that allows a wire to be easily connected. These
breakers have a flip-type actuator that is up when on, down
when off, and in the center when tripped. Figure 8-11 shows
a typical home power center. Always select a power center Arc Suppression
with a main breaker as shown. It is also a good idea to label
the breakers. Labeling can make de-energizing a circuit a sim- The formation of arcs during the opening phase of contacts
ple matter instead of an arduous chore. can be extremely damaging. This is the principal reason for
Circuit breakers are manufactured in extremely large sizes to snap and pseudo-snap action switches. The contacts are
provide circuit protection for large power distribution systems. opened very fast, mitigating the damaging effects of the arc.
Figure 8-12 shows a 240,000 volt, 40,000 amp circuit breaker As voltages and currents get higher, special provisions must
which is used to protect cross-country transmission lines. be made to limit arc damage.

200 200 Main Circuit Breaker
MAIN ON ON MAIN
Internal Panel
Double Pole Breaker

Air Conditioner ON 40 50 ON Stove
Air Conditioner ON 40 50 ON Stove
Cabinet
Dryer ON 30 20 ON Water Heater
Dryer ON 30 20 ON Water Heater
Hot Tub ON 50 Blank Space
Hot Tub ON 50
Bed Rooms ON 20 20 ON Kitchen
Bath Room ON 20 20 ON Garage
Front Porch ON 15 15 ON Patio Circuit Label
Living Room ON 15

Single-Pole Breaker
Door
Figure 8-11 Home Power Center