socomec ATyS p M - Over-Voltage and Under-Voltage

44
EN
ATySpM - 542935E - SOCOMEC
13.5.7. Over-voltage and under-voltage
The thresholds and hystereses are dened as percentages of nominal voltage.
The hystereses denes a return to normal levels following an under-voltage or over-voltage.
Checked value (voltage)
%
100
T
Source available
Upper threshold (oV. V)
Lower threshold (und. V)
upper threshold
hysteresis (oV. V Hys)
lower threshold
hysteresis (und. V Hys)
13.5.7.1. Voltage unbalance measurement
U 13
3
U 32 U 21
3’
U 1’3’
U 3’2’
N’
N
2’
U 2’1’
1’
1
2
3
1
2
Balanced network Unbalanced network
The unbalance reading is derived from the formula below
U
nba
=
max (
U
12
- U
avg
, U
23
- U
avg
, U
31
- U
avg
)
with U
avg
=
U
12
+ U
23
+ U
31
U
avg
3
Example of an unbalanced network: U
12
= 352 Vac U
23
= 400 Vac U
31
= 370 Vac
U
avg
= (352+400+370)/3 = 374 V AC
U
nba
= 26/374 = 0.069 => Unbalance threshold rate 7%