Electrical Ring circuit

任何電力裝置做好後一定要測試, 小型電力裝置俾電前最少需要4種測試 :

1. 絕緣測試 = 用500V DC米加 insulation
2. 極性測試 = 可以用電鈴鐘 polarity
3. 水線導通測試 = 可以用電鈴鐘 earth continuity
4. 水線導地電阻測試 = Earth Tester = test earth resistance

環形電路需要多做既

極性測試 = 可以用電鈴鐘 polarity

其實你已經做咗啦。

俾電後

LN 極性測試 = 可以用他筆 test pen
漏電保護斷路器測試 = 需要特別儀器earth leakage tester 或
用一個10W燈泡



2010-05-29 21:21:04 補充：
1. 絕緣測試 = 用500V DC米加來測量 insulation test
至少要0.5MΩ至夠

2. 極性測試 = 可以用電鈴鐘來測量 polarity test
因為測量極向一個係總制一個係廚房，係遠程睇唔到要用來聼

3. 水線導通測試 = 可以用電鈴鐘 earth continuity test
因為測量水線導通一個係總制一個係廚房，係遠程睇唔到要用來聼

4. 水線導地電阻測試 = Earth Tester = test earth resistance
如果冇 Earth Tester 較難測試，你可以用一個較高電壓既直流電同一個電壓表加一個電流表就可以，不過要計算好麻煩。

2010-05-29 21:21:15 補充：
用一個10W燈泡測試LN 極性同漏電保護斷路器

L - N 燈泡亮
N - E 燈泡不亮
L - E 漏電保護斷路器跳制，如果唔跳制就證明漏電保護斷路器無效

2010-05-29 21:23:56 補充：
因爲 RCD 敏感度係 30mA，電壓係220V，30mA = 0.03A

220 X 0.03 = 6.6W

10W 已經超過跳制電流

2010-05-31 18:32:18 補充：
你去買一個用4粒D型乾電池既 Ring 聲電鈴鐘，將按鈕既兩條電線接去 Fuse 箱或 MCB 箱既 E 同 L ，如果 E 同 L 冇短路電鈴鐘當然唔會響，如果 E 同 L 有短路電鈴鐘當然會響啦，你明唔明我既意思呀。

唔明再問l啦

[email protected]

2010-05-31 18:33:58 補充：
記住！唔好開電試呀，如果開電試，你九條命都唔夠死啦

2010-06-01 00:30:36 補充：
希望你成功，如有唔明
[email protected]

點解要用電鈴鍾和10W燈泡?

2010-05-30 18:37:59 補充：
咁我想問下點用電鈴鐘?

2010-05-31 20:27:01 補充：
吾該!!
我買架生!!

Ring Circuit

Normally, ring circuit is formed by 2.5 sq. mm cable (min) and 32A protective device, i.e. each outlet is feed by 2 pairs of 2.5 sq. mm cable in parallel.

In case of breakdown in continuity, each outlet is feed by 1 pair of 2.5 sq. mm cable but protected by a 32A protective device, it will be a risk to overload the 2.5 sq. mm cable without tripping the protective device when the load is concentrated at one of the cables.

Radial Circuit
The cable is sized adequately to carry full load of the circuit protective device, in case of breakdown in continuity, part of the outlet will lost power, hence the circuit loading will be reduced, no any risk and people could be alerted.

My Experience
As breakdown of continuity in a ring circuit would have potential risk of fire and peoples would never been aletred after test, so that I never use 2.5 sq. mm cables in a ring circuit protected by a 32A protective device, My design always use 4 sq. mm cables in the ring circuit to prevent the risk of fire due to continuity broken down.