Tuesday, April 26, 2011

Neutral Link Pictures

I just wish to show a few pictures of electrical neutral links here.
Picture 1 – Neutral links on electric meter panels at a commercial shops building

Electrical fuses and neutral links are among the most commonly discussed items on consumers’ discussion forums such as Yahoo Answers, etc.

Many times, the higher the number of people who gets involved in a trying to answer a simple electrical question, the more confused the issue becomes.

Instead of understanding more, many beginners often get confused and sometimes misled.

A few pictures or diagrams could have made a significant difference to the beginners who were trying to understand some basics of electrical installations. But then I guess many of those forums do not provide facilities for attachment of graphics.

Now, the pictures.

(Note: I took the above photograph at a commercial shop-lot building a few months ago. Never mind the blue pieces of paper below the electric meters. They were survey stickers left by the national statistics department. The department was doing a survey of the local population when I took the picture.)

There are two kilowatt-hour meters on the picture.

So there are two units of neutral links there.

Picture 2 – A neutral link unit

This is a close-up view of one of the unit on the panel. I did not look at the rating of the cut-out fuse there.

However, it could not have been less that 100A. A standard cut-out fuse rating for single phase supply to a normal house is 60A. A commercial lot like this would need more usually.

I have not been doing design or supervision on commercial lots of this types for some time. I am getting rusty.

Picture 3 – Neutral link, cut-out fuse and kWh meter connections

Here is a good picture to use if you wish to test how good you are in electrical connections.

The electric meter panel on the left has not yet been installed by the electricity supply company.

This is a newly completed building and a number of the shop units have not yet been occupied.

The electric supply company would only install the meter if the owner or the tenant of the unit submits the supply application form and pay the necessary connection fees and deposit.

Apparently the owner or the new tenant has not yet done so.

The good thing is you can understand more clearly how the wiring on the meter panel including the connections to the neutral link are run.

The cartridge of the cut-out fuse also has not yet been installed. So you can see the inside of the fuse base more clearly. The picture below shows them at a closer view.

Picture 4 – Base of cut-out fuse installed but not yet wired

Now see the picture below and test yourself if you can mentally complete the wiring of the meter panel on the left. You can use the completed panel on the right as a guide.

Picture 5 – Meter panel wiring test

If you think the neutral link on a house electric meter panel is kid’s stuff, then look at the photograph below.

Picture 6 – Internal wiring of a three-phase electrical distribution board

This is a three phase electrical panel for the lighting and power of an office floor.

If you look closely, you will notice that the incoming power cables are not yet terminated to the panel’s incoming circuit breaker.

The incoming cables are still dangling down from the top of the panel going wown on the right side.

Observe also the rows of miniature circuit breakers (MCB) near the top of the panel. The is no wiring yet on one side (the lower side) of the MCB terminals.

This is because this distribution boards is factory manufactured. All internal wiring are done at the factory.

The wiring that goes out of the panel would be don’t at the construction site. Here the supply cable to the panel has been installed. Only the termination to the main circuit breaker has not been carried out.

Back to neutral links. Look at the picture below:

Picture 7 – Neutral link of main incoming circuit breaker

Here is the neutral link of the main incoming circuit breaker.

This neutral link is installed inside a protected compartment. That is why it look so different from the neutral on the electric meter panel in the earlier pictures above.

The meter panels were exposed. So there has to be some enclosure to protect the component inside and also the connections of the cables.

Inside a protected compartment like this distribution board, many of electrical components are simply bare.

The neutral link here is just one example.

Picture 8 – A closer view of the neutral link

Notice that only one side of the neutral link hase been connectied by a cable. This the internal wiring that has been done at the factory.

The terminal without cable connection yet is the one to be connected to the neutral cable of the incoming supply.

Observe also that the cable is terminated to the neutral link terminal using an “O” ring type of cable lug.

This is very important in the connection of power electric cable and wiring. A ring type of cable lug has a hole at the center. The bolt would go through this center and hold the cable firm with two nuts above and below the cable lug.

(Note: If you are not sure what a cable lug is, it is a conductor extension that is installed at the end of a cable conductor so that the connection to a terminal can be made much easier, faster and much much more reliable.)

Even terminal connections of an 11kV high voltage cable are done using a similar ring type of cable lug.

Picture 9 – 11kV cable terminations

Picture 10 – A closer view of the ring type of cable lug for high voltage cable

I added this picture on 11kV cable termination just to emphasize this very important point in electrical installations: the soundness and reliability of power cable connections.

Well, I guess that is all I wanted to say on neutral links today. I just wanted to show the pictures so beginners have a “confirmed” view of what it is.

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1 comment:

prolix said...

I loved ur blogs and wat information that u issued is really very usefull for us .. thanks...............
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