The use of neutral busbars in-circuit distribution boards is common. But did you know that there are other ways to derive the neutral in the QDC? In this article, we will cover the main ways to perform the derivation of the neutral within the QDC. Come on guys!
Three ways to derive neutral cables
From the input standard supply comes the general neutral cable, which normally has the largest section, and the thinner neutral cables in the circuit will come out from this general cable, so neutral must be derived between the circuits inside the QDC, that is, each circuit will receive its neutral cable.
Adequate mechanical tightening must be carried out in the cable derivation, the gate is not just to wrap the cables with each other, as this type of connection does not guarantee the proper tightening of the conductors, thus there may be great heating of the cables.
Connecting the cables through a split bolt connector is the first solution to avoid cable bundles in the QDC. To use the split bolt connector, simply place the cables in the connector slot and tighten with two spanners or some suitable hexagonal wrench. In the case of the split bolt connector, it is necessary to do the insulation because the connector is loose in the frame and can touch an energized part, causing a short circuit.
Its biggest disadvantage is that when it is necessary to disconnect the neutral of only one circuit, you will have to disconnect all other cables because when the connector is opened all the conductors will come loose.
Neutral bus with screws
Our second solution is the neutral bus with screws, which is already known by many professionals. The neutral bus with screws is widely used in electrical installations, due to its ease to make the cable connections, as it is only necessary to connect the main cable to the larger diameter terminal and on the other smaller terminals connect the neutral cables that go to the circuit.
A great advantage of this bus is that it does not need to be isolated because it is fixed to the panel and there is no risk of touching anything energized. Another advantage is that when measuring voltage with the multimeter using the bus neutral, the access point for neutral is already exposed and there is no need to remove the insulating tape. The disadvantage that we can mention of the bus with screw is that from time to time it is necessary to retighten the screws.
Pressure clamping busbar
The pressure clamping bus is an evolution of screw busbars. In the pressure clamping busbar only the main cable with the largest diameter is connected with screws and the other cables are only fitted to the busbar.
To fit the cables that go to the circuit, just place a small screwdriver in the smaller hole, above the largest hole, where the neutral cable of the circuit goes, then force the key upwards that the space for connecting neutral cable opens, allowing cable connection. After the cable is connected, just remove the key and the cable is already secured by the mechanical system of the bus.
The advantages of the pressure-tight neutral bus are the agility to connect the cables to the bus and you do not need to retighten all cables because only the main one has a screw. This type of bus usually came in QDC, but there are several bus models on the market with this same technology. It is worth researching more and discovering this new option.
Below is a video of the Mundo da Elétrica channel, showing the main connectors for electrical installation.