DMC написал :
Возвращаясь к теме:
Никто не ставит узо только для защиты оборудования.
Узо ставят, чтобы они отключали линию питания аварийного оборудования, для исключения попадания человека под опасные напряжения и токи.
Да это понятно. Насколько мне известно, и разрабатывалось УЗО именно для защиты человека, а не оборудования.
А байка про "защиту оборудования" идет, imho, от пиндосов. Как и надписи "не глотать силикагель".
Стандарты у них жесткие, в тюрьме сидеть не хочется...
Поэтому и пишут: до 6ма - защита жизни, а выше - оборудования. Типа - моя хата с краю, никого защищать не обещал.
Тут вот, несколько цитаток от производителя:
Q. Some of TRC's HD-PRO units are called GFCI's others are called ELCI's.
Why the two definitions?
A. GFCI's (Ground Fault Circuit Interrupters) are considered personnel protection devices, whereas ELCI's (Equipment Leakage Circuit Interrupters) are considered equipment protection devices.
Q. What is the difference?
A. Effectively they work the same way. They both sense unwanted current to ground and shut power off, however, a GFCI (by commonly accepted US standards) must shut power off when it senses current leakage of 6mA maximum, whereas an ELCI can be set to shut off power at almost any current leakage level.
Q. Why not have all devices set to sense 6mA?
A. The main reason is nuisance tripping. The higher the voltage (example: 480V vs. 120V) or the heavier the current (example: 80A vs.15A) the more likelihood of natural leakage. TRC has selected levels that are in line with heavy-duty machinery and applications.
Q. Does that mean that anything over 6mA will not offer human protection?
A. No, what it really means is that personnel protection standards for high current and voltage higher than 120V above ground, have not been established by UL. Consequently, until this issue is addressed, any trip level over 6mA can only be called an ELCI. If a person touches a 120V line (across the line and neutral conductors), approximately 100mA's will flow through their body. An ELCI with a 10 or 30mA trip level will shut off the power long before maximum current is reached.
Q. Why do the Europeans have a different standard than the US?
A. It is difficult to set up tests that are consistent because of all the variables: The human body varies in size and conductivity, the area of contact and the location of contact with voltage and ground varies, the amount of water or moisture and the amount of minerals in water or moisture varies, and the conductivity of the ground varies. Add to that the varying sensitivity of each person's heart to defibrillate when subjected to 50 or 60Hz of alternating current. UL has taken an ultraconservative approach to personnel protection by setting standards that try to protect the entire population. The Europeans set standards premised on protecting the vast majority or approximately 95% of the population.
