WEG SRW 01, User Manual

Page: 74 / 148

Parameterization
5-28 | SRW 01
5
External CT application examples (P295 = 7).
Example 01:
Motor Nominal Current: 650 A, therefore, P401 = 650.
Number of the external CT secondary turns through the UMC/UMCT: 1 turn, therefore, P296 = 1.
External CT ratio: 800:5, thus the external CT primary current is 800 A, P298 = 800 and the external CT
secondary current is 5 A, P299 = 1.
Example 02:
Motor Nominal Current: 80 A, therefore, P401 = 80.
Number of the external CT secondary turns through the UMC/UMCT: 2 turns, therefore, P296 = 2.
External CT ratio: 100:1, thus the external CT primary current is 100 A, P298 = 100 and the external CT
secondary current is 1 A, P299 = 0.
NOTE!
The SRW 01 informs the average current, P003, and the percentage current, P002, without the need
of any conversion.
NOTE!
The Control Unit (UC) signalizes through the status led in red and with the message “E0082” on the
HMI, if the motor nominal current (P401/P402) is out of the UMC/UMCT range. Motor starting is not
allowed as long as the relay remains in this condit,ion, but it leaves the error condition without a reset
command as soon as a valid setting is performed, signalizing the new condition through the status led
in green and removing the E0082 message from the HMI.
E.g., message “E0082” using external CTs with a 200:1 ratio, with two CT secondary turns through the UMC1/
UMCT1, so that the number of turns n = 2, and the motor nominal current adjusted in 48 A.
The transforming factor (K) used to calculate the current reading range for external CTs is obtained dividing the
ratio 200:1, resulting in a factor K = 200. As the UMC1/UMCT1 current range goes from 0.5 to 5 A, by using
the external CT with a 200:1 ratio, the maximum current will be 200 A and the minimum will be of 0.5 x K/n,
resulting in 50 to 200 A.
For more information, refer to the Section 3.7 EXTERNAL CURRENT TRANSFORMER (CT) USE on page 3-7
of this manual.
P400 – Motor Nominal Voltage
Adjustable
Range:
0 to 1000 V Factory
Setting:
380 V
Proprieties: Sys, CFG
Description:
It defines the motor power supply voltage.
P401 – Motor Nominal Current 1
Adjustable
Range:
0.0 to 5000.0 A Factory
Setting:
0.5 A
Proprieties: Sys, CFG
Description:
It defines the motor nominal current.
For the operation modes Transparent, Overload Relay, Direct on Line Start, Star/Delta and Reversing Starter, the
motor nominal current is adjusted through the parameter P401.