How To Do Wiring For 1 Way, 2 Way and Intermediate Switch?

As for wiring for light fitting, there 3 method of switching that can be used; 1 Way, 2 Way and Intermediate Switch.

1 way is the basic of all switching method. The circuit only using single switch to control all lighting connected to that particular circuit.

2 way switch normally used for a long span of corridor, staircase, sharing toilet (with 2 doors) and room that has a two access doors.

User will have an option to switch ON or OFF the light fitting at either side of those switches. This is the advantage of using the 2 way switch compared to 1 way switch.

The other switching method is using the intermediate switch whereby more than three switches being used to control the same lighting.

These 3 types of wiring using different type of switches. Therefore, it is crucial for you to identify what type of switch to be use…otherwise the wiring won’t work.

At the front plate of switches..all looks the same, you only can identify the differences by looking at the back of those switches (the cable terminal). Figure below illustrate the differences of those switches.

Okay, by now you should knew the concept and switches to be used..this is the final part, how to do the wiring!

Figure below illustrate the wiring diagram for 1 way, 2 way and intermediate switch.

Wish you all the best..tq.

Generator Set..What Supplier Might Not Telling You!

Today I learned a very important thing...the thing that some of the Generator Set (genset) supplier hidden from you or maybe something that the supplier overlook into...the coolant for genset!

Due to some incident at other projects..the Client requesting us to inspect on the coolant’s  liquid for those genset installed at site.

Surprisingly, we notice that those genset are only filled with water inside its radiation system but there are no coolant being added in. We taking sample of the coolant liquid and the colour are plain white. It indicate that, no coolant liquid being added and the radiator is only filled with water.

Normally, the coolant liquid are coloured green (some might colour red).

Water is actually one of the cooling agents. However, as the genset generally made from metal, using water are not advisable as the metal tend to rust.

So, those water need to be drained out and the radiator must be fully flushed. Then, refill the coolant into the radiator...make sure you witness the process!

So guys, BEWARE..do check the coolant liquid for your genset.

How To Calculate The Size Of Projection Screen

Below is the sample calculation to calculate the projection screen.

You must first indentify the furthest distance of audience. Let says10m.

By using the aspect ratio of 10/6 (based on AV formats: video or NTSC (4:3), HDTV (16:9)), you can identify the screen height.

Screen Height           = 10/6

                                                            = 1.67m

                                                            = 5.5 ft

                                                            = 66 inch

Then, you need to define the video format screen (assume you using 16:9 format)

Therefore, screen width       = 16/9 x 66 inch

                                                                        = 117.3 inch @ 2.97m

Based on the calculation above, the standard projection screen of size: 116" x 65" is proposed.

Once you have the size of projection screen, you need to determine the projector luminance.

           

Projector luminance = (Width x Height x Room Lux Level) / screen gain

Normally the screen gain will be unity = 1 and Room Lux Level = 300 lux

            Therefore projector luminance = (2.97m X 1.67m x 300 lux) / 1

                                                                = 1487 ANSI Lumens

Therefore the standard luminance of 2000 ANSI for projector will be proposed.

Below is the size of projection screen according to their aspect ratio for your reference.

Video Format (4:3 Aspect Ratio)
Image Diagonal	Image Height	Image Width
60"	36"	48"
72"	43"	57"
84"	50"	67"
96"	57"	77"
100"	60"	80"
120"	69"	92"
150"	87"	116"
180"	105"	140"
200"	120"	160"
210"	123"	164"
240"	141"	188"
HDTV Format (16:9 Aspect Ratio)
Image Diagonal	Image Height	Image Width
92"	45"	80"
106"	52"	92"
110"	54"	96"
119"	58"	104"
133"	65"	116"
159"	78"	139"
188"	92"	164"
216"	106"	188"
220"	108"	192"
AV Format (1:1 Aspect Ratio)
Image Diagonal	Image Height	Image Width
71"	50"	50"
85"	60"	60"
99"	70"	70"
108"	60" (5')	90" (7.5')
119"	84"	84"
120"	72" (6')	96" (8')
130"	72" (6')	108" (9')
136"	96" (8')	96" (8')
151"	84" (7')	126" (10.5')
153"	108" (9')	108" (9')
170"	120" (10')	120" (10')
173"	96" (8')	144" (12')
204"	144" (12')	144" (12')
238"	168" (14')	168" (14')
272"	192 (16')	192 (16')
305"	216 (18')	216 (18')

Source: www.da-lite.com