Page 290 - L . V S W I T C H G E A R

intelligent
RING MAIN hNIT

Earth fault indicator (EFIS):

In the case of one of cables went down and touch the earth,
ƚŚĞƌĞ ĂƌĞ ϭ ĐŽŝů ƚŽ ĞĂƌƚŚ ĨĂƵůƚ ŝŶ Ϯ;<>Ϳ н ϭ;<>&Ϳ ZDh͘
Ϯ ĐŽŝů ƚŽ ĞĂƌƚŚ ĨĂƵůƚ ŝŶ ϯ;<>Ϳ нϭ;<>&Ϳ ZDh͘
/ƚ ĐŽŶƐŝĚĞƌ ƐĞŶƐŽƌ͕ ƐĞŶĚ ƐŝŐŶĂů ƚŽ ĞĂƌƚŚ ĨĂƵůƚ ƐŽ ŝƚ ƐŚŽǁ ŇĂŐ ĂŶĚ
ŝƚ ƚĂŬĞ ϮϮϬǀ͘
/W͗ ŶLJ ƌŝŶŐ ŵĂŝŶ ƵŶŝƚ ŚĂƐ /W
/W͗ ͞ŝŶĮůƚƌĂƟŽŶ ƉƌŽƚĞĐƟŽŶ͗͟ /WŶϭ ŶϮ
N1: for dist.
N2: for water.
ŶĚ ǁŚĞŶĞǀĞƌ ƚŚĞ ŶƵŵďĞƌƐ ŝŶĐƌĞĂƐĞ ŝƚ ŝƐ ŵŽƌĞ ƉƌŽƚĞĐƟŽŶ ĂŶĚ
safety.

Kiosk The kiosk In the case of maintenance:

The volume of kiosk depends on the consists of:
size of the transformer which will Ring main unit – 1. The earth knife is open.
be used. transformer – low 2. Open electrical knife then close earth
There kiosk 12kv and 24kv. knife to any electric seep to it.
voltage. 3. ŌĞƌ ŵĂŝŶƚĞŶĂŶĐĞ ŽƉĞŶ ƚŚĞ ĞĂƌƚŚ ŬŶŝĨĞ
Consist of: ƵŶƟů ŝƚ ŝƐ ĐůŽƐĞ ĞůĞĐƚƌŝĐĂů ŬŶŝĨĞ͘

Primary coil – secondary coil – iron core.
The idea of working:

1. dŚĞ ĐƵƌƌĞŶƚ ƉĂƐƐ ƚŚƌŽƵŐŚ ƚŚĞ ƉƌŝŵĂƌLJ ĐŽŝů͕ ŐĞŶĞƌĂƚĞ The transformer:
ƚŚĞ ǀĂƌŝĂďůĞ ŵĂŐŶĞƟĐ ĮĞůĚ͘ ƚƌĂŶƐĨŽƌŵĞƌ ŝƐ ĂŶ ĞůĞĐƚƌŝĐĂů ĚĞǀŝĐĞ ƚŚĂƚ
2. dŚĞ ǀĂƌŝĂďůĞ ŵĂŐŶĞƟĐ ĮĞůĚ ĐƵƚ ƚŚĞ ƌŽůůƐ ƐĞĐŽŶĚĂƌLJ ĐŽŝů͕ takes electricity of one voltage and changes it
ŐĞŶĞƌĂƚĞ ŝŶĚƵĐƟǀĞůLJ ĞůĞĐƚƌŝĐĂů ǀŽůƚĂŐĞ͘ into another voltage.
3. dŚĞ ŝŶĚƵĐƟǀĞ ǀŽůƚĂŐĞ ĐĂƵƐĞ ƉĂƐƐ ĐƵƌƌĞŶƚ ǁŚĞŶ ƉƵƚ ƚŚĞ
load.

DrLJ transformer – oil transformer.

The oil transformer:

The oil help in cool the transformer, the oil transformer must re-
ŵĂŝŶ ƐƚĂďůĞ Ăƚ ŚŝŐŚ ƚĞŵƉĞƌĂƚƵƌĞƐ ĨŽƌ ůŽŶŐ ƟŵĞ ƚŽ ŝŵƉƌŽǀĞ ĐŽŽůŝŶŐ
of large power transformer.
Kŝů ĮůůĞĚ ƚƌĂŶƐĨŽƌŵĞƌƐ ǁŝƚŚ ƉƌŽƚĞĐƟǀĞ ƌĞůĂLJ ŵĂLJ ŚĂǀĞ Ă ŐĂƐ ĚĞƚĞĐ-
ƚŽƌ ; ƵĐŚŚŽůnj ƌĞůĂLJͿ͘ dŚĞƐĞ ƐĂĨĞƚLJ ĚĞǀŝĐĞƐ ĚĞƚĞĐƚ ƚŚĞ ĂĐĐƵŵƵůĂƟŽŶ
of gas inside the transformer due to corona discharge, high tem- Dry transformer:
ƉĞƌĂƚƵƌĞ͕ Žƌ ĞůĞĐƚƌŝĐ ĂƌĐ ŝŶƚĞƌŶĂů͘ dŚĞ ƐůŽǁ ĂĐĐƵŵƵůĂƟŽŶ ŽĨ ŐĂƐ͕ Žƌ
the rapid rise in pressure, used to either alarm or de-energize the It used for cooling the
transform. (Oil transformer more used). air or fans.

The important in the transformer room:

Ex: Input 11kv.
ZĂƚĞĚ ƉŽǁĞƌ ϭϬϬϬǁ͘ KƵƚƉƵƚ ϰϬϬǀ͘

292