Toshiba GRL100-701B Instruction Manual page 260

default setting of the UVCV is 48 V.)
•
Choose a test current IT by referring to the table below, which shows the relation of setting
reach UVCZ, test current IT and measuring error.
UVCZ
0.0- 2.0Ω
(0 - 10Ω
2.1 – 10.0Ω
(11 - 50Ω
10.1 – 20.0Ω
(51 - 100Ω
20.1 – 50.0Ω
(101 - 250Ω
(*) Values shown in parentheses are in the case of 1A rating. Other values are in the case of 5A
rating.
•
Set the test voltage and test current phase relation as shown below. That is, V a , V b , and V c
are balanced, and IT lags V a by UVC characteristic angle UVC θ .
(The default setting of UVC θ is 85°.)
•
Adjust the magnitude of V a while retaining the conditions above and measure the voltage V a
at which the element operates.
• The theoretical operating voltage is obtained by (IT × UVCZ + UVCV) when the setting
reach is UVCZ. Check that the measured voltage is within the above-mentioned error of the
theoretical voltage value. (The default setting of the UVCZ is 2.0 ohm for 5A rating and 10
ohm for 1A rating.)
Element UVCV
UVCZ
6.5.1.5 Directional Earth Fault Element DEF
The testing circuit is shown in Figure 6.5.1.7.
DEF elements and their output signal number are listed below.
Measuring element
DEFF
DEFR
The following shows the case when testing DEFF.
IT
10A
5A) (*)
5A
1A)
2.5A
0.5A)
1A
0.2A)
V a
θ
V c
UVCZ IT
Signal number
611
612
 259 
Error
±5%
±5%
±5%
±7%
IT
V b
Measured voltage
IT×UVCZ + UVCV
6 F 2 S 0 8 5 0