Woodward WIC1 Series, Оригинальное техническое руководство, Страница: 41 / 58

Technical Manual WIC1 Woodward
DOK-TD-WIC1E, Rev. L 41
5.12 Adjustment instruction for inverse characteristic
In the introduction phase of the WIC1 it came to understanding problems during the adjustment of the protection re-
lay, in particular when using inverse characteristics. In the following now the connections are for this described.
Notion definition:
I
S
= Setting value of the load current
With the parameter Is the operating current of the protected equipment is set. Due to the application of wide range
CT’s the use of only one CT for a wide primary current range is applicable. All further setting parameter are related
to the parameter Is.
I> = Pick up value of the over current element
With this parameter the pick up value of the over current element is set. Here for it is to distinguish between the use
of an defined time characteristic or inverse time characteristic.
At the use of a defined time characteristic the parameter I> specified the pick up value of the overcurrent element.
Exceed the measured current the factor Is

I> the WIC1 will pick up.
At the use of a inverse time characteristic the parameter I> specified the starting point of the characteristic curve.
Means, that the factor Is

I> is the starting point of the characteristic curve at one times of
1 ×
𝐼
𝐼
𝑆
×𝐼
>
.
t
I>
= Delay time of the over current element by use of DEFT
a = Time multiplier of the characteristic curve by the use of INV
This parameter serve to delay the trip of the WIC1 after a pick up occurs. By the use of a defined time characteris-
tic the WIC1 trips when the pick up still exist at the time elapsed.
By the use of a inverse characteristic the factor a shift the characteristic curve (see diagram).
I>> = Pick up value of the short circuit element
With this parameter the pick up value of the short current element is set. Exceed the measured current the factor IS

I>> the WIC1 will pick up.
t
I>>
= Tripping time of the short circuit element
This parameter serve to delay the trip of the WIC1 after a pick up occurs. The WIC1 trips when the pick up still exist
at the time elapsed.
I
E>
= Pick up value of the earth fault element
With this parameter the pick up value of the earth fault element is set. Exceed the measured current the factor IS

IE> the WIC1 will pick up.
t
IE>
= Tripping time of the earth fault element
This parameter serve to delay the trip of the WIC1 after a pick up occurs. The WIC1 trips when the pick up still exist
at the time elapsed.