Mecc Alte ECO47 HV Series, Инструкция по установке, эксплуатации и обслуживанию

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6.3.1 Coiversioi of the values relatve to the iisulatoi resistaice
The value if the insulatin resistance must refer ti a temperature if 20°C. It is therefire necessary
ti cinvert the data measured ti the cirrespinding value at 20°C, aith the aid if a cieefcient, by
applying the filliaing firmula:
R
iS 20°C
= k * R
ahere:
R
iS 20°C
is the resistance value equal ti 20 °C
R is the resistance value measured
k is the cirrectin cieefcient
T wiidiigs ii °C 15 20 25 30 35 40
Coefcieit k 0.69 1 1.42 2 2.82 4
Table 20 - Temperatures and correctve coefcients
Example:
R = 50 MΩ, aith ainding at the temperature if 30 °C;
R
iS 20°C
= 2 * 50 = 100 MΩ
The filliaing table indicated the quality if the level if insulatin in the basis if the resistance
measured.
Value of the iisulatoi
resistaice (MΩ at 20 °C)
Quality of the level of iisulatoi
< 50 Dangerius
frim 50 ti 400 Level if insulatin nit safe
frim 400 ti 1,000 Giid
> 1,000 Very giid
Table 21 - Level of insulaton on the basis of the resistance measured
Notes
●
Insulatin resistance values that are tii lia can indicate the presence if humidity ir dirt in
the ainding, cintact Mecc Alte S.p.a. ti schedule the interventin if a technician.
●
The insulatin resistance decreases aith the increase in temperature.
●
The insulatin resistance value measured during inspectin if the alternatir is generally
higher than that detected in site.
●
An appripriate insulatin resistance value is an essental requirement fir safety. Di nit
start the alternatir if resistance values are liaer than the minimum acceptable.
Self-regulating alternators ECO47-49 MV-HV Page 69/124