• # Can we connect multiple electrical bulbs on single wire connection?

Want to save electrivcity by connecting many bulbs to one wire? Searching for techical advice regaridng whether possible and safe? Find responses from experts here.

We have one electrical point outside house but we wanted to add more lights ( surface or spot lights) so question is can we connect multiple lights lets say 7 lights using one light connection?
We are ok if all lights glow on single switch, only question is if we wanted all 7 lights ( 5 spot lights , 1 hanging light and 1 connection for small led lights) on one connection is it possible? if Yes then how to do it?

• Yes. You can connect. But the wire you are using is to be good enough and should have the required load-bearing capacity.
There are two methods. You can connect in series or you can connect in parallel.
Connecting in parallel will be a good way so that if one bulb goes also the remaining bulbs will work. Even if you want individual switches in between you can provide. This will make to operate individually also.
In fact, in all our house we will have incoming single wire only. From that single source, we have multiple connections in parallel. We will not have a separate source for each wire.
The voltage in a parallel circuit is the same at each point but the flowing current is different. Any number of lighting points or load can be added, But the wire used should be of required strength. The same concept is used in serial seta we will using for decoration on Deepavali day.
You can connect in series also but if there is any problem in one bulb point from there the other bulbs will not work.

drrao
always confident

• You have one electrical point outside. You have not told what is its strength means how much current load it can take. Normally it would be a 5 Ampere point which means that a total of 5 Ampere current can flow through it and if you draw more than that then the wires which are coming to this point from the house wiring may get burnt due to the excessive heat generated in them. By chance if it is a power point then one can comfortably go up to the load of 15 Ampere.

Let us understand it now through your case. In all probability you would be using the CFL bulbs as they are drawing less current and giving good light as compared to the conventional glass filament bulbs. Let us assume that you are using CFL bulbs of 12 watt rating. So, one such CFL bulb will be drawing some current from the mains (220 volt) and that current value can be found as -

current drawn by one 12 watt CFL bulb = 12/220 = 0.55 Ampere.

Now you want to use 7 bulbs. You have to use them in parallel only as in series they would glow very dim or may not glow at all. Please note that the whole wiring in a house is in parallel mode only and each appliance gets directly the 220 volt for its operation.

So, 7 CFL bulbs would draw a current of 7 x 0.55 = 3.85 Ampere which is well below the 5 Ampere which is normally the capacity of household points. Hence you can use 7 CFL bulbs comfortably from that single point.

Knowledge is power.

• You have mentioned that there is only one electrical point outside the house but have not mentioned what is the current rating of the point, that means how much current the point can deliver to the load. I am sure the switch for that point is fitted inside a switchboard where multiple switches and sockets are also there for other points inside the room and either connected to a fuse or MCB which trips if there is overload. Normally, the switchboards inside our rooms can deliver up to 10 Ampere current and is sufficient for a good number of lights and fans but they are not suitable for heavy loads like refrigerator or AC for which a separate point with heavy load capacity is required. Now, let's come to the calculation of current supplied to the loads. I am not complicating this by adding power factor (cos phi) in the formula and making a simple calculation. We will use the formula W=V * I, where W(Watt)=Power, V(Volt)= Line Voltage across the load which is 230V in India and I(Ampere)= Current consumed by the load.

For one 20Watt LED baton, the consumed current is 20/230 = 0.09A, for a 70Watt ceiling fan the consumed current is 70/230 = 0.3 A. For example if there are 10 such LED batons/bulbs of 20W each, the total consumption is 0.9A and if there are 2 ceiling fans of 70W each, the total consumption of current will be 0.6A. By adding these two: 0.9A+0.6A = 1.5 A. So out of 10A, you are using only 1.5A inside that room. Generally, we do not connect a load of more than 100W in a point and if the load is 100W then the current consumption of the load is 100/230 = 0.43A. So, in your case, if the total number of lights connected to that point which is outside of your house is within 100W, you can safely connect them without worrying. Nowadays, we use LEDs and they consume very less power. A 10W LED lamp provides enough light and in that particular point, you can connect 10 LED lamps in parallel. Do not make the connection series since it will deliver less current to the lamps and will glow dimly.

One precaution, if the wire of that point outside is lying naked for a long time check the condition of the wire and if there are leakages you need to replace the wire. The connection is shown with the help of a diagram.

Sankalan

"Life is easier when you enjoy what you do"

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• You have indicated that there is one external electrical point out side your home but the rating of ampere has not been provided for such an arrangement where the wire is to be used for glowing seven bulbs. However, rating in terms of ampere is always indicated such as 5 amp, 10 amp, 15 amp etc.
However, for a middle sized family consisting of six members provision of 10 amp is enough to take care of your varied electrical consumption sand for a large family they may go in for 15?amp.
Now let us calculate the power drawn for each 12 watt LED bulb per hour. LED bulbs are ideal for saving the power. Now according to the formula, Volt * Amp = Watt, we can calculate our consumption in terms of ampere.
Here the supply voltage is 220 V, watt of the LED bulb to be utilised is 12 watt, hence current drawn for each LED bulb is equivalent to 12/ 220 =0.054 amp
Hence for the arrangement for seven such bulbs would consume 7* 0. 0.54 amp = 0. 378 amp indicating that power consumed is much less than the minimum rating of 5 amp.
In case of 60 watt ordinary lamp consumption already calculated will be five times higher and it would correspond to 1.890 amp, still below the rating of 5 amp.
We have chosen the parallel arrangement for better glowing of the bulbs.
The arrangement can be changed to series arrangement but in that case, the glow of the bulbs will be feeble.
Now consider the characteristics of the wire to be chosen, the following conditions would be ideal-
1) It should have sufficient rigidity and corrosion does not take place with the passage of time, otherwise the flow of current would not be continuous.
2) it should have high electrical conductivity for the uninterrupted supply of current. Aluminium wires are considered having best electrical conductivity and cheaper than the copper wires.
3) Aluminium wires are lighter than the copper ones and such a provision is cheap.

• Dear friends,
Total 7 lights with 5 of them of 3W each and 1 light of 6W and remaining lose end planned to connect for LED multicolor lighting which we put on parapet wall of gallery during festival approx with 150 small lights.
Existing power supply is given with 5amp and in 1sqmm wire. Please tell me if this will work?

Avi
Life Is Beautiful

• When you talk about connect 7 lights using one light connection, it means that you would like to have a series connection i.e. in a series connection, the current through each light is the same and the voltage across the lights is the total of the voltage across each light connection. Most of the house connections are not connected in series as adding or removing any additional light/connection in the circuit will affect the overall circuit. It is best prefered to connect in parallel because adding or removing one lamp from the circuit does not affect other connected devices or lights as the voltage at each device or point is same but only the current flowing is different.

Q: Can we connect multiple lights lets say 7 lights using one light connection? if Yes then how to do it?
A: Yes, you can connect all the lights as mentioned in your query in parrel as diagram attached. You can even control every connection by having a hanging switch as shown in the attached diagram.
1. Take the 2 wire which is Line or live shown in red colour and denoted as "L" and the wire in black denoted as "N" in parallel.
2. Connect a wire to your light from each wire as shown in the diagram. One from the red wire "L" and the black wire "N".
3. You can even install a switch in between each light on the Line/live wire shown in red "L" in the diagram. This will allow you to switch "ON" or "OFF" as and when required, without closing the complete line.

Advantage of Parallel wiring for multiple connections:
- Parallel connections are easy, safe and trustworthy to install and do the wiring.
- At any point in time, you can add more light or points in the circuit without overloading the circuit.
- Any problem with a single light in the connection won't disturb the other connections and they will work as normal without affecting the other lights or circuit.
- Parallel connection helps to get an independent connection for each light which can be easily switched ON / OFF using a switch.
- If you need to add more points to the circuit, you just need to extend the Line(L) and Neutral(N) wire and add the connection point.
- Always select good quality wire for parallel connection with high gauge for more connection.

“The most important thing in life is to learn how to give out love, and to let it come in." — Morrie Schwartz

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• Yes, you can safely connect 5 lamps of 3 Watt, 1 lamp of 6 Watt and an LED chain. In my previous reply @#160505, I have said that if the switchboard from where this particular electrical point is taken has more points connected to it, say 10 LED batons and 2 ceiling fans, the maximum power consumption would be 1.5 A.

For this particular point, the total calculated power becomes 5*3 + 1*6 + 3 = 24 Watt. The maximum power consumption of the LED chain having around 150 lights is 3W. By applying the formula, given in my previous reply the current requirement for this particular point is 0.1A. If the current required for the lights and fans inside is 1.5 A, the total current comes to 1.6 Ampere which is much less than the rated power of 5 Ampere. A good quality copper wire of 1 sq mm can safely withstand 5 Ampere of current and you can connect the lamps according to the diagram shown in the previous reply without any problem.

Sankalan

"Life is easier when you enjoy what you do"

• Most of our experts have given their best responses yet I wanted to give my version that connecting so many bulbs with a single wire is not advisable nor safe. Because each bulb is having wattage and if the connection grows beyond the acceptable watts, then the load would be more on the single wire and the entire connectivity and there would be flareup and even electrical short circuit. Normally we have seen serial bulbs of zero watts are connected to each other and made as the big line of connectivity to adore the buildings and even made to blink at intervals. But connecting the bulbs same way would prove to be dangerous and not advisable.

K Mohan @ Moga