EpDc House

In 2013, someone gave me a layout drawing paper, He wanted to build his elder sister's 3-storey house. He was my coworker in  small contractor company Rawasari, Jakarta.
He needed my help to design of electrical construction of his paper layout, I was glad to help him plus practiced developing my ability in electrical. That was my second experiences designing for electrical.

In this Blog, I"ll show some tricks of electrical consultant company to design electrical construction of  Public Houses, Goverment, Business , High Risk , and Industrial Building with limiting voltage 220V, 380V and 20KV, also Electrical Network Distribution Low Voltage and Medium Voltage.
( With f = 50 hz, PUIL standard is adopted from IEC, NEC Standard). Each problem and solution that  Autocad File ( Autocad 2009 version or above) is enclosed

Example 1:
1.See this layout figure 1.1 pdf below, all these pdf file in high quality are suggested to download.

Figure 1.1 Layout Public House

After consulting with owner, he need some lamps and electronic devices placed into each room as shown figure 1,2 below

                  Figure 1.2  Electrical Equipments Position that were needed by Owner

NOW QUESTION, according to both figures above, try to make it,s electrical construction !


SOLUTION
Follow These Steps
Step 1 : Calculate the Total of Electrical Load in WATT unit , then convert into VA unit
Step 2 : Find the Main MCB and Main Cable refer to the Table or formula
Step 3 : Divide into several smaller groups ( Branch MCB ), then make the Single Line Diagram
Step 4 : Find the Grounding Cable on stick rod by formula
Step 5 : Describe  all groups  into Layout

Step 1 
By seeing all layout, there are 15 of Downlight Lamp 18 Watt , 3 of TL Lamp 18 Watt, 5 of Downlight plc Lamp 18 Watt, 1 of Park Lamp 8 Watt, 4 of Wall Lamp 8 Watt, 1 of AC 2Hp ( 1 Hp=736 Watt ), 2 of AC 0.5Hp, 1 of Exhaust Fan 100 Watt, 3 of TV 100 Watt.
But we need Sockets, sometime we have to use electrical equipment mobile such as Hair dryer, Ironing Cloths then plug in. Assume a socket about 200 Watt,
so the Total Watt of Electrical Loads would be:
(15 x 18) + (3 x 18) + (5 x 18) + (1 x 8) + (4 x 8) +  (1 x 1472) + (2 x 368) + (1 x 100) + (3 x 100) = 4770 Watt.
Now convert Watt into VA with formula VA = P/Cos Ø, where  P = Watt and Cos Ø=power factor In Indonesia the cos Ø usually about 0.85 or 0.8.
In this Blog we use Cos Ø = 0.85 So, VA = P/Cos Ø = 4770/0.85 = 5612

Step 2 :
As described aboved that Rating Power 5612 VA associated with yellow color on the table 1.a below

Table 1a MCB and Cable Sizing According To VA

Note :
The content of the table is adapted to the size of the MCB available in Indonesia Electrical Stores, or you can adjust the size of the MCB or Cable is available in your country by formula :

I = P / ( Vln x Cos Ø ) = VA / Vln       with Vln = V line netral = 220 Volt         …… for 1Ø
I = P / (1.73 x  Vll x Cos Ø ) = VA / ( 1.73 x Vll )    with Vll = V line line = 380 Volt  ...… for 3Ø

Example: A dozen lamps and 3 Electric Fan in your home with total 800 Watt,
So,  I = P ( Vln x cos Ø ) = 800 ( 220 x 0.85 ) = 4.3 Ampere, then you want to buy MCB at electric store, the clerk of the store simply  give you MCB 6 A, since MCB 4.3 A is not available at the store.

Step 3 :
As describe above, The Main MCB is 25A we can make it into 3 groups MCB, there are MCB 20A, MCB 6A and MCB 6A.

But as you know the total would be 32A , that’s not problem because if one MCB overload the electricity will  trip itself securely. The groups can be shown as figure 1.3 below

Figure 1.3  Single Line Diagram

If several Lamps are set in one group ( one MCB ) that highly recommended   total Watt not exceed 1500 Watt. If an Electric Motor ( AC, refrigerator, etc ) exceed 1500 Watt, generally it’s set to one group except in this case.

Step 4 :
Grounding Cable sizing ( usually BC Type )  that connected to stick rod is found as follows:
if S ≤ 16 mm² ,  so BC grounding’s size is S mm²
If 17 mm² ≤  S ≤ 35 mm³ , so BC grounding’s size is only 16 mm²
But if S ≥ 35 mm² , BC grounding’s size is S/2
Where S = Cable Size
So, according this equation, we got BC cable grounding that connected to stick rod about BC 4 mm²

Step 5 :
Finally, by set all cable, MCB and others we get Electrical Construction as describe this figure 1.4

Figure 1.4  Electrical Construction Design

KWH meter is usually placed  outdoor 1.8 meter high from floor and must be easy to be reach by electrical technician company. Panel is usually placed  indoor 1.6 meter high from floor and mus be easy to be reach by owner's house. Socket and Switch is usually placed  indoor 1.2 meter high from floor near rooms or doors and but the switch or socket is not hidden or covered while we open the door,You can download Autocad File version here of the PDF fictures above if you need to

Example 1  Example 2