School of Engineering

Electrical Engineering Division

Six-month Industrial Attachment Programmed

WithCPG CONSULTANTS PTE LTD

Bi-Monthly Second Report for the period

21th APRIL to 15th JUNE Student Name : Sim Boon Chuen

Student Number : S10046265E

Contact Number : 90669564

IAP Group : M&E

Liaison Officer : Chan Chee Hin

Declaration by student:

1. I confirm that my report has been seen by my supervisor

2. I declare that no part of this assignment has been copied from any other person’s work except where acknowledged in the text, and no part of this assignment has been done by any other person on my behalf.

Supervisor Name/Signature Student Signature

Content Page

1) INTRODUCTION

2) AUTOCAD

PART 1 – LIGHTING LAYOUT

PART 2 – POWER LAYOUT

3) VIPCODA

4) APPENDIX

INTRODUCTION

As part of my attachment so far in CPG consultants M&E department at design Team, I have involved in assist the engineer to input data in Vipcoda to simulate the result. I also understand their design requirement and be able to differential the needs to improve on the design and look for mistakes made and require to feedback to the person in charge of the projects or to troubleshoot certain things that we encounter to the design.

As a designer the scope of work involves mainly on operate using AutoCAD and also system design.

In this report I am writing about the electrical software VIPCODE and AutoCAD application that I have used it in my daily works progress and in detail with some attachment.

It has further developed into few sections for easy referencing. For AutoCAD topic I will be explaining in details on light fitting and Power outlet point that were input in drawings and included with design.

AUTOCAD

PART 1 – LIGHTING LAYOUTIntroduction

As a consultant most of our job involve designing and planning for putting our electrical items like PowerPoint, light fitting and projecting audio in the building. In order to give a better explanation, the things example is broken down into a few sections for easy references

AutoCAD set up

In order to save time and trouble to configure the setting of a new drawing, we will open an old drawing that we use in the previous project, and then we delete all the item previous left behind. Next we will set to the architecture layering. After that we will use a UCS command to rotate the UCS world before we begin to bring in the new architecture drawing under external reference, to ensure that the rotation is at its original place.

Lighting Design-overview

Before we start to an idea of how many light fitting is needed in that area, we can start to do a draft on our design, we have to look at the construction of the building in a 3 dimensional way instead of just in 2 dimensional in AutoCAD. We will print the layout in A1 size for better viewing and analysis but before we begin we have to learn to read and study the elevation and section of the building. While we study and look in the drawing we might also want to highlight and mark out some common area like toilet, corridor and plant room to allow easy identification and to save time to search for common areas later on. We might also look into section consider whether there is any obstacle that prevent us from putting the light fitting. For example whether there is a collar that prevents lighting to be mounted or is there a glass wall that does not allow us to mount, the height of the ceiling whether a not we need to suspend the lighting instead of mounting it. We have to be aware of this entire factor in order that our design. Also not to forget to provide a water proof lighting if it is use outside.

Choosing the area to start

We will zoom in to the area we want to start on, example we choose to start on the car park areas. Before we start to design our lighting layout, first we have to do a calculation on the area to determine the number of lighting needed for that particular place. Normally we will start with some common areas like the basement car park area as it is usually the standard and the same as the rest of the basement car park.

Lamp selectionLamp selection has a great impact on us design because it will influence on the qualities of light fitting we are able to put. This will also affect the operating costs of the lighting installation. Before we start to select a particular light, we will have to consider the criteria for the area we are planning.

After we decided what area to start working on, we have to consider what light fitting we will need to use for the car park area. Normally the choice of light fitting is quite standard for common area like basement car park and so we will be using suspended fluorescent light. The reason why we chose suspended fluorescent light rather than surface mounted is because for basement car park there is no ceiling provided for us to mount the light fitting and so suspended type would naturally be the best. After we decided to use suspended light fitting we can now check the catalog to choose the desire watt. For car park we will select the 28W with the luminance of 2600lm.

Suspended light fitting (PICTURE BELOW)

Surface mounted light fitting (PICTURE BELOW)

Catalog on fluorescent lamps (PICTURE BELOW)

Calculation Of Lighting Qty. required

For our calculation we base on the formulate below [ Lux level x Area/ luminous x maintains level x reflection level ]

*lux level is defined as the mount of illumination provided when one lumen is evenly distributed over an area of one square meter.* Luminous flux is to present the total amount of light emitted by a light source, the SI Units is Lumen (lm)

We will need the lux level, area, luminous, maintain level and the reflection level in order to do a calculation. The area will usually be provided by the architecture in their layout drawing but at time they might not have include them in the layout so we have to calculate the area by ourselves, one of the way include drawing the area using polyline then we type in the command list “LI” which will give us the area inside the polyline drawn.

Checking the area using the command LIST “LI” (PICTURE BELOW)

Base on the List in AutoCAD text window we found out the area which is 82meter square, with the area now we can process to find out the others value needed for the formula. The lux level can be found in the catalog for the type of light we choose. This is an important choice because the luminous we choose will affect the number of qualities of light fitting we can put, so it will be wise to go for a low luminous if we find there are not enough light fitting.

Next for the luminous we have to check our SS CP531 Lighting of Work Place, which will give us the luminous for the place. Base on CP531 the parking areas lux level is given at 75, but for security reason we might want the area to be brighter so we round up to 100.

SS CP531 On lux level (PICTURE BELOW)

As for the maintenance level and reflection level we use an assumption of 0.8, 0.6.

Now with the values, we can now calculate the number of light needed. We will substitute in the value using the formula [ Lux level x Area/ luminous x maintains level x reflection level ][100x82/2x2600x0.8x0.6]=3.28

After we calculate the number of light we usually will get a decimal. so in this case the value calculated is 3.3, normally in this case we will round up the value to the next whole number to avoid underestimate of light fitting that would cause insufficient luminous for the eyes. After rounding up the whole number which means we need to install 4 lights fitting for that area.

Design-LayoutNow that we have all the information needed, we can start to plan and position our lighting. But before we place the light fitting, here are two of the things that we might have to consider, firstly maintenance and secondly positioning of the light.

Design-maintenance Also another important thing to consider when we plan our design is maintenance. It is important that we do not just place our light fitting for the particular place, we have to take consideration that whatever design we plan it is actually safe and easily assessable for that maintainer to maintain. In this section, we might have to consider the surrounding area whether a not it safe. For example is there any obstacle that prevents them from reaching or in any case cause inconvenient to them that may expose them to danger. Let take a look at example 1

Lighting Layout Example 1 (PICTURE BELOW)

Lighting legend (PICTURE BELOW)

If we look at the drawing most of us would agree that there is nothing wrong with the design. The design is acceptable as long as it does no contradicts with the code of practice but is that a good design. We must also take in considerate that whether our design can be easily assessable by the maintainer which in this case this design has failed to provide. Just imagine that during normal operating hours in the day what if there is a car occupying under the light, and then the maintainer will not be able to reach the light with a ladder. Let us take a look at the second example.

Example 2 (PICTURE BELOW)

Now with the light positioning center between the car park lots we will provide sufficient space for the maintainer to position their ladder highlighted in red.

Design-position of light

The next thing to look out for is how we place our light whether it is in horizontal or vertical. If we place our light in the horizontal direction the vertical area will get more lighting and vice versa. As we can see in example 3 that how we position our light greatly affect the amount of light it can cover.

Example 3 (PICTURE BELOW)

PART 1 – LIGHTING LAYOUTDesign-overview

Designing where to put our PowerPoint source might seem to be simple but we want to make sure that we take note of the following points.

Design –layoutUsually by our standard for placing a PowerPoint source should be provided near the entrance of the door for convenience. We have to look out for some services like plant room which we have to provide metal clad and emergence source, so that in case of power failure we still have supply for maintainer to rectify the problem. Another important thing to take note of is that PowerPoint place in the toilet have to be at least 2m away from any water supply and it has to

be at mounted at high level. This is to prevent any water from getting contract with the power point from short circuit.

Legend with description (PICTURE BELOW)

Plant room services have to be metal clad and provided with emergence source. (PICTURE BELOW)

Toilet has power point have to be high level and water proof. (PICTURE BELOW)

VIPCODA SOFTWARE

Introduction

We will receive the information from the engineer for the data for the circuit which included the load, the circuit breaker, the type of cable and the distance. With the information given, we will input the value into the vipcoda programmed. At time the information given by the engineer may not be complete, for example the circuit breaker may still be unknown, so we as a designer might have to assume the breaker rating to get a better overall result simulated. For example lighting and power point we will assume it to be 10A and 20A.There are a few thing we might have to take note of when we are inputting the value given by the engineer. Firstly we to take note on the tripping time when selecting a breaker for the motor due to high starting current and it might cause the breaker to trip. After we key in the value we have to do test run to make sure that our circuit is safe and compile to the standard of cp5.Here are the list of test that are require to pass in order that our circuit is safe

Breaker and cable load test Breaker test allows us to check whether the design current, Ib exceeds the protective devices current rating, In.(Ib<In)

Breaker and Cable load test (PICTURE BELOW)

As we can see in the picture above, the value highlighted in blue show us that the breaker and the cable load have fail the requirement. The design current have exceeds the protective device current rating which cause it to fail. So in this case the design current is 20.98A and the protective device MCB is 6A.In order that pass the requirement all we have to do is to change to a higher MCB rating than the design current.

In this case we need to change a higher rating mcb. (PICTURE BELOW)

As we can see that after we change to a higher MCB rating than the design current 20.89<25 we can now fulfill the requirement Ib<In which Vipcoda indicate a pass highlighted in pink.

Now with the breaker test solve we move to troubleshoot the cable load. Cable test check whether our design current Ib under the condition does not exceed our capacity of the conductor Iz. The reason it fail because it does not satisfy the requirement Iz>Ib. Which in this case our Iz is 18A and Ib is 20.89A. If we take a look at our CP5 under the copper conductor (the picture below) we can see that for conductor with cross sectional area of 1.5mmsq the highest value it can support is 18A so we need to consider to upsize the cable which the 2.5mmsq can support up to 25A.

SSCP5 copper conductor single core pvc insulated cables, non armored, with or without sheath. (PICTURE BELOW)

After changing to the 2.5mmsq cable we meet the requirement. (PICTURE BELOW)

Overload protection testThis test put the design circuit to an overload conditions, for vipcoda it will increase the current to 145% of the rated circuit capacity Iz. Also the time taken for the test is 2 hours. Take a look at the picture below as it fail the requirement of I2<1.45 Iz. For this case OL_P_YES = -38.89%, negative value show us how much we fail to provide the protection.

Overload protection test fail. (PICTURE BELOW)

The solution to this is to upsize the cable in which this case 2.5mmsq will pass the test. (PICTURE BELOW)

Voltage dropThis test the voltage drop between the origin of the installation and the final distribution broad should not exceed 4% of the nominal voltage of the supply which is based on the CP5. Before we conduct the test we must first estimate the amount of voltage drop tolerance on each design based on the design. For the example below the design is under the voltage tolerance of 1%.

Voltage drop sample (PICTURE BELOW)

Short circuit protection testThis test the protective device whether it operate quickly in order to prevent damaging the cable insulation. The clearing time of the protective device under both short circuit and earth fault conditions shall not result in the permissible limiting temperature of the conductors being exceed. The example below show that the design does not pass the short circuit protection. The SC_P_YES = -170.4% show that the cable is unable to withstand the fault current. So in this case we might have to increase the size of the cable to meet the requirement.

Short circuit protection test fail. (PICTURE BELOW)

Only when the cable is at least 10mmq then we pass the requirement. (PICTURE BELOW)

Now for the BKC which represent the breaking capacity, if we look at the 16kA highlighted in blue, the value is higher than the 1.5kA our circuit provided so the solution to this might have to change to a higher rating of the MCB but for MCB the highest kA rating is up to 15 so we have to consider to change it to MCCB which can support up to 100kA.

After we change to MCCB with a rating of 25kA our design fulfill the requirement. (PICTURE BELOW)

Earth fault and CPC testIn the event of an earth fault, the circuit protective conductor (CPC) carrying the earth fault current to the main earthling terminal of the installation and form part of the earth fault loop impedance. This test verifies whether the CPC size is adequate to withstand the earth fault current.

Earth fault and CPC test fail. (PICTURE BELOW)

Above picture shows us the earth fault sending is 8kA and the earth fault receiving is 1.61kA.the maximum CPC withstand time is 0.01836 sec where the breaker operating time (T_blk) is 0.02sec. The reason where it fail is due to the breaker operating time is more than CPC

withstand time. This is to say that when there is a fault current our cable will break down first then follow by the breaker tripping, so when this happen the cable may cause fire and endanger the surrounding. So to solve this problem we have to we can use a bigger cable size to support a higher CPC.

So by getting upsizing the cable which increases the CPC size we can pass the test. (PICTURE BELOW)

Conclusion

For the past 4 months attach to CPG Consultant, my job of scope mainly involve in using AutoCAD application to do our designing. At the beginning it might seem to be a routine job but as time goes by I found out that my concept was wrong. Firstly the same discipline use in this project will be different to another one, so the previous discipline that I have done can only serve as a reference. For example a toilet for school is totally different form commercial, for school toilet there is a standard guide line on how their toilet should be as the commercial depend on the client budget. Commercial toilet most likely comes with sensor on their hand wash so power source have to be provided on each hand wash.

Software application like Vipcoda enforce the things I learn in school, in order to understand this application, I appreciate that without my background on electrical I will not be able to understand the concept and let alone troubleshooting problems. I also understand what are the thing that are taught in school can be apply.

There are things I learn here that are not taught in school like using excel to create formulas for others to simulate their result and I also get a chance to do learn proper documenting on the CD containing project that are completed and those currently on hold. The important of proper documenting is to allow item to be retrieve back easily when needed.

There are still a lot of thing to be learn and I will take all the opportunity given and try to make the best out of this 2 months before finishing this attachment.

Appendix

List of reference books and the Code of Practice used during the last 4 months of my Attachment are as follows

1) SINGAPORE STANDARD CP 5: 1998 CODE OF PRACTICE FOR ELECTRICAL INSTALLATIONS

2) SINGAPORE STANDARD CP 530: 2006 CODE OF PRACTICE FOR ENERGY EFFICIENCY STANDARD FOR BUILDING SERVICES AND EQUIPMENT

3) SINGAPORE STANDARD CP 531: 2006 CODE OF PRACTICE FOR LIGHTING OF WORK PLACES