The most daunting part of working with electricity, namely installing an automatic switch in the electrical panels of residential buildings, does not have to be dangerous. Here are some simple, step-by-step steps to help you do it safely.
Step 1. Turn off the power to the electrical panel
Find on the panel of the shield "Introductory" or General machine and turn it to the "Off" position. This switch is likely to be the largest and most likely to be at the top or bottom of the panel. If you did not find such a switch on the panel, then it is probably on another switchboard in the house or built into the meter body. Look for other shields to find the switch you need.
Step 2. Check the placement of circuit breakers for unused locations
Pay special attention to unused spaces at the top and bottom of the lid. Some manufacturers of electrical panels have removable plugs or plates in these places, but the panel itself lacks the internals necessary for installing the distributor. Simply put: don't rely on the cover alone to determine if you can add switches to the panel - check the bus.
Step 3. Remove the shield cover
Remove the latches while the assistant is supporting the cover, then immediately pull the cover off.
Step 4. Check the electricity in the panel
Using a tester or meter set to the highest possible AC range (120 volts minimum), test it for current by touching one sensor to ground (strip where bare or green and white wires are connected - or strip where only bare wires are connected or green wires). Touch the other sensor to the switch terminal to which the black, red, or blue insulated wires are connected. If it shows 120 (or more) volts, the shield is still energized. If the input or general machine is on this panel, the voltage will always be indicated at the terminals to which the cable is connected. If the general or input circuit breaker is located on the panel, it is connected to the bus. When it is off, there should be no current in the bus. It is not recommended to check on a service input or general machine because of its "possibly conflicting" indicators. "Do not proceed if there is current on any distributor other than the input or common distributor until the power supply has been turned off." '
Step 5. Find unused space above, below, or between existing breakers
A single-pole or single-line breaker creates a 120 volt circuit (or, in the case of a "daisy-chained circuit breaker" or "half-circuit breaker," creates two 120 volt circuits, rather than one 240 volt circuit), while a double or two-way circuit breaker the switch forms a 208 or 240 volt circuit. Compare this location carefully with the previously removed cover. It is very important that there are blanks in the lid in order to open the new switch by removing the metal blanks. If there are no blanks, then the circuit breaker must be installed in a different place on the panel.
Step 6. Select the appropriate switch
The panel label will list all the circuit breakers that are permitted to be installed. Deviation from the list is a violation of the instructions and voids the approval of UL, FM or other registration services. Usually it is allowed to install only switches of the same manufacturer as the manufacturer of the switchboard - even if the switches of other brands say that they “fit the switchboards (here is the brand name)”. In the United States, Canada and other countries, a single pole switch is used for a 120 volt circuit and a double pole switch is used for a 240 volt circuit. The circuit breaker must have a permissible current load that does not exceed the standard of the circuit conductor. Typically 15 amps for # 14 copper conductors or wires, 20 amps for # 12 copper and 30 amps for # 10 copper. You need to consult the instructions to determine the dimensions of other chains. Breaker terminals must be selected to suit the conductor material, CU for copper and AL for aluminum. The terminal must be large enough to connect the wire. The need to remove the cores of the cable in order to fit it to the terminal is an indicator of an error somewhere on the wire.
Step 7. Locate the attachment points for the circuit breaker
The switch will have two attachment points. Both are mechanical contacts; one of them also serves as an input electrical contact. Both contacts are either at the bottom or very close to the bottom of the circuit breaker.
- The non-electrical contact is at the screw terminal end of the circuit breaker. This end is used first during installation. The contact consists of a clip, bracket or protrusion and works with a supporting structure on the outside of the flap, specially designed for this. The clip is pressed and latched onto the raised rail of the Square D QO and other circuit breakers to clip the clip from the panel. Well, the protrusions used in other types of switches are simply connected to the groove on the bus.
- The electrical contact is at the opposite end of the circuit breaker. This end is used last during installation. The contact mechanism is often located inside the switch; it can be partially seen through a groove or hole in the housing. It fits snugly against the “bus” (metal ribs or hinges in the center of the backboard) after mechanical contact has been applied. The electrical contact is established when the switch is fully connected to the busbar: a simple downward push is all it takes to fully engage.
Step 8. Set the machine lever to the OFF position
The circuit breaker has 3 possible positions: ON, OFF and middle position when fused. Push the lever toward the OFF position until the switch moves to that position.
Step 9. Install the circuit breaker by placing it in an unused location on the panel
Turn the switch so that the mechanical contact enters the base element (rail, groove or clamp). When it enters, fasten the circuit breaker to the mechanical contact and twist towards the center of the panel - making sure that the shield bus remains attached to the groove or hole in the breaker body. Press down firmly on the surface of the switch to ensure that it is fully seated. If you need constant, even pressure to insert it, no force is needed. Compare it with those switches that were installed earlier.
Step 10. Connect the chain
After making sure that the switch is in the OFF position, connect the conductors or wires to the terminals of the switch, which are neutralized by the contact screws. Use an oxidation inhibitor when connecting aluminum conductors.
Step 11. Get rid of all foreign objects
Remove tools, wire cuttings, etc. from the inside of the shield. Look for and remove "stray conductors" in the switchboard that could cause a short circuit when the current is restored.
Step 12. Install the cover
Move the lid to the panel to compare the position of the new vending machines with the holes in the lid. Remove metal blanks in appropriate places. Slide the cover over the shield to ensure that the switch is fully seated at both points of contact. The circuit breaker should not "protrude" under the cover. Remove the cover and push it into the shield as far as necessary to make the cover sit properly. Secure it with snaps to the shield.
Step 13. Verification
Standing on the side of the switchboard, restore the power supply to the panel by switching the input or general circuit breaker to the "On" position, and then switch the new circuit breaker to "On". If it constantly turns off, then eliminate the cause of the short circuit before turning it back on. Check the correct operation of the new switch (light, output, etc.) with a test indicator or test device.
Step 14. Designate the chain
Find the "chain location" on the panel. It is usually found on the inside of the dashboard door. Determine the location that the switch is responsible for (or "circuit number") and label the circuit (load type - for example, "refrigerator", or location - for example, “living room”) in a designated spot. Be sure to change the entry if any circuits have been removed to install a new one.
- Under certain conditions, a voltage of 50 volts can also be fatal. For most electrical systems in residential buildings, this value is 2-5 times higher. Always turn off the current when working on circuits, and never proceed unless you are sure of the next step or are uncomfortable with taking it.
- Never place a circuit breaker in an enclosure for which it was not designed. Many switches will fit different panels physically, but only those indicated on the panel label are allowed for use. Use of circuit breakers not listed will result in the loss of UL, Factory Mutual and all other “registrations”. The use of unregistered devices is a violation of the instructions, and in extreme cases can lead to the refusal of the claim by the insurance company in the event of losses.
- Always stand to the side when turning on the machines. The amount of energy transmitted is directly proportional to the current values in the circuit breaker. If shorting one pole at 15 or 20 amps does not cause catastrophic harm, then a short on two poles at 100 or 200 amps can definitely do it. If a person stands to the side at a distance, this largely (though not completely) renders him “inaccessible”.
- In the United States, 120/240 systems (most commonly installed in apartments and houses) use color codes for wiring: black, red, blue “high voltage wires” and white neutral. In addition to the 120/240 volt systems found in residential environments, many commercial and industrial installations also have 277/480 systems. These higher voltage systems use a different color scheme to alert an electrician immediately to a high voltage switchboard. The color scheme used for these systems is brown, orange, yellow "high voltage" and gray neutral. Make sure the new wiring is installed in the correct panel.
- Before using any tester or measuring device, make sure it works from the first test on a live working circuit you are familiar with. If the instrument does not display normal data, do not use it until it is repaired or replaced.