A circuit breaker is designed to stop the power flow through a circuit if there is an excessive amperage drawn on said circuit. Occasionally, these breakers go bad and will need to be changed. It is highly recommended that you hire a licensed, competent, and insured electrician to perform this task, as electricity can be deadly. However, if you choose to replace a circuit breaker yourself, you’ll need to know how to find the breaker box, take note of any issues, and replace a faulty breaker to get your power working again.
Sooner or later, each of us may face the moment when it is time to replace the circuit breaker in the electrical panel.
How to replace an electrical outlet
Why does the electric breaker need to be changed
-the machine stopped holding the load
-frequent false positives, etc.
If the machine you have started to knock out, and there are no signs of damage to it (blackened housing or burnt insulation on the wire), first find the reason for its operation and never rush to change the machine for a large amount.
Remember that the machines are selected primarily based on the cross-section of the cable connected to them, and only then look at the load.
How to change a breaker in the dashboard
The expression “replacing the breaker with a voltage release” means that not only this switch must be disabled, but all the voltage before it must be removed. As a rule, to do this, turn off the input machine, the switch, or the bagger that feeds the entire switchboard.
After disconnecting using an indicator screwdriver or voltage tester, check and make sure that there is no voltage on the contacts.
Next, loosen the screw clips on the switch at the top and bottom.
You can do this with either a cross or a flat screwdriver since the profile of the screws in modular breaker is designed for any of them. If the contacts were previously heated and melted, then you will not be able to Unscrew this screw. This happens very often on aluminum wiring. This metal eventually weakens and begins to flow. The contact relaxes more and more.
So, if it is impossible to Unscrew the screw, just snap the wires themselves with side cutters or pliers in a clean place where there is no melting or blackening of the insulation.
You only need to connect the cleaned, clean ends of the wire to the new machine. Otherwise, the whole situation will happen again very soon. Then pull the wires to the side and proceed to dismantle the switch.
How to remove the machine from the rack
Almost all modern modular vending breakers are mounted on a DIN rail. It may differ in size and profile, but the principle of mounting any switching devices on it is the same.
Find the U-shaped eye at the bottom of the switch. Insert a small flat screwdriver into it and pull it down. If you have a two or three-pole machine, ouzo or diffstat such eyelets maybe two pieces. You will have to delay each of them.
Then, without removing the screwdriver, use it as a lever to make a slight upward movement and release the lower part of the machine from the Din rail.
Then lift the body of the machine up and completely remove it from the fastener.
It seems to be simple and elementary, but in the cramped conditions of a small shield, all these fragile eyes often break. This is not a problem with old switches, but the new one is worth saving.
Another nuance is that some of the eyelets are spring-loaded. Once you pull the screwdriver out of them, they immediately come back.
This is especially inconvenient on two and three-pole models. You have to show miracles of dexterity.
In addition, the above-described dismantling is easily performed on a single breaker or devices connected both from above and from below using a conventional single-core wire. But there are switches that stand inside the entire Assembly, powered through a so-called phase comb.
This is a very convenient and reliable thing that has long been used by all electricians. So, if you need to change the machine in such a row or chain, you will have to Unscrew all the contacts, all the switches where this comb goes.
Then pull it out and only then remove the desired switch. You will not be able to do this in any other way.
If you have an old-style machine that is firmly attached to the screws with a thread, directly to the metal base, then the main problem will be associated with unscrewing these very screws.
Instead, it is recommended to install modular instances. To do this, a short piece of DIN rail is attached to the screws, and a new breaker is mounted on it.
Installation of the breaker in the panel
The installation of the new modular device is performed in reverse order. First, the upper part of the switch sits on the DIN rail.
Then the eye is pulled back with a screwdriver and the lower one is pressed. After that, the lower grip is lowered and snaps into its seat.
All you have to do is connect your contacts. If you have previously had stranded conductors compressed by the corresponding tips, then you simply wind them back into the upper and lower clips and tighten the screws.
If the vein was without a tip, then there is a high probability of its deformation, bending, etc.
In this case, if there is a stock of wire, it is better to bite out the old tip and clean it again. After that, use a screwdriver to clamp a fresh, not deformed conductor.
At the same time, do not overdo the tightening effort. On inexpensive modular circuit breakers, the screws are very easy to break. It is also dangerous to “tighten” the contacts.
Each clip-in such devices must be “pulled” with a certain force calculated by the manufacturer of the device.
What other mistakes can you expect with such a seemingly simple operation as replacing the machine?
1. Getting just in time’s clamp contact with the insulation.
- Connect several cores of different cross-sections to a single terminal. Quite often, under the same machine start two veins at once. This is mainly used on the upper terminals, where such cores act as jumpers. In this case, it is better to use the factory comb. After connecting the wires, apply voltage to the machine by turning on the input switch. Next, you need to check how the new device behaves under load. Plug-in electrical appliances at home and make sure that the contacts of the switch do not have any cracks, crackles, heating, and other extraneous effects.
Replacing the machine under voltage
Now let us consider the case when you cannot turn off the voltage, and the burned machine, one way or another, needs to be replaced. This may be due to the absence of an input switch or switch. Alternatively, you need to replace it. Sometimes the package is changed to this switch, which will then play the role of an introductory one. By the way, in this case, instead of a simple machine, put a load switch.
The first thing I would like to note is that if you have no experience in working with electricity, never replace live protection devices yourself. Invite experienced electricians to do this.
Remember the main rule
- Work under voltage should only be performed with a special insulated tool that has passed the test up to 1000V and designed for this type of activity.No screwdrivers with bare Stingers or pliers with their handles wrapped in duct tape.
- .You should not work with your bare hands, but with gloves. If you have a dielectric, this is the best option.
At the same time, the feet should also be shoes, not simple Slippers. It would be appropriate and dry the rubber Mat from the bathroom.
- All the work in the electrical panel under-voltage, like a surgical operation. And as with any operation, you must have a second person present next to you. Never do this alone.
Step-by-step instructions and hazards when replacing an electric switch under voltage
Now let’s look at the procedure itself. First, turn off the machine that needs to be replaced.
You will change it, although under-voltage, but without load. Next, it is very important to determine which side of the power supply is suitable and which of the conductors you have remains energized.
The power supply to the machine is not always supplied from above, so check both clips with an indicator screwdriver. One of them will have a light bulb, the other will not. It is worth making an important digression here. If you have a voltage on the machine is fed through a comb bus, then I hasten to disappoint you – it is easy and safe to replace one switch without de-energizing, you probably will not succeed. You will not be able to simply disassemble the old machine from this very tire, without disconnecting it from all the other devices in the chain. This makes it very difficult. After you find out where the supply conductor is, Unscrew the screws with an insulated screwdriver. First, the one with no voltage. Then on the second, where there is.
When you Unscrew the second screw, the second-hand pliers, be sure to hold the vein. At the moment of loosening the contact, the conductor can jump out or spring in the most unexpected direction.
You must anticipate and prevent this situation in advance. This is especially true in cases when the feeding vein is stretched by a branch from the nut from the driveway riser. If you do not Unscrew the phase wire, but bite it out with side cutters, do it as far as possible from the metal bar in the shield. Since at the moment of biting the core, the blades of the pliers are automatically energized. And if you accidentally touch any part of the case with them, there will be a big boom! Since all metal parts in the electric panel are a common zero. Accordingly, accidental contact with them will immediately cause a short circuit.
Moreover, in a common panel with the counters of other apartments, this single-phase short circuit can quickly switch to interphase, with much more serious consequences. After the dangerous wire is removed, a piece of shrink wrap is put on its end or it is simply wrapped with duct tape. Your task is to isolate it in any way possible while you change the machine.
When replacing a three-phase input module under-voltage, all these operations are performed alternately with each phase. Just don’t forget to mark and remember the phasing and the correct position of the phases. When the reserve allows, pull the disconnected conductor as far away as possible. At the same time, be careful with its second end, which it is connected to, for example, a bag or nut in the riser.
With strong bends, the core may break off or simply pop out of a poorly clamped contact. And then you will have more to do. If such trouble still happened on the nut, then reconnect the wire on it without paying off the entire riser will not work. In this case, it is much safer to fork out a little and buy one piercing clip. Often there are cases when you need to go through the entire 3-phase panel in the entrance, but they do not allow disconnections.
In this situation, you bite off the old taps from the riser, made on nuts, and throw out all the excess. Then, without tension, calmly and safely assemble a new circuit and connect everything again to the riser through the piercing clips. But back to our machine. After removing the wires from it, remove the old machine according to the instructions described at the beginning. Mount a new one in its place.
Connect the wire to it first without voltage, and then, removing the insulation from the tip of the phase core, gently pliers it into the machine. All that is left is to tighten the contacts well. Turn on the load and check the device’s performance.