SMY 133 U 400 X/5A N 4
L1
L2
L3
N
PE
k
l
k
l
k
l
SMY 133 U 230 X/5A N 4
SMY 133 U 400 X/5A N 4
L1
L2
L3
k
l
k
l
k
l
Option S:
10 ÷ 26VAC
10 ÷ 36VDC
Option U:
85÷275VAC
80÷350VDC
Option L:
20 ÷ 50VAC
20 ÷ 75VDC
SMY 133
S
230 X/5A N 4
Figure 4: An example of typical installation of SMY 133 instrument in a low voltage network — option U (left)
with power supplied from the measured channel in a star connection and option S (right) with low voltage DC
power supply, measurement connected as delta connection — based on the power supply option various AC and
DC power supplies can be used including battery backed UPC etc.
SMY 133 U 400 X/5A N 4
L1
L2
L3
N
PE
333 mV CURRENT SIGNAL INPUTS
SI1
SP
SG
SI2
SP
SG
SI3
SP
SG
SMY 133 U 400 X/5A N 4
L1
L2
L3
N
PE
333 mV CURRENT SIGNAL INPUTS
SI1
SP
SG
SI2
SP
SG
SI3
SP
SG
Figure 5: Typical installation of a X/333mV option of SMY 133 instrument in a low voltage network with power
supplied independently. Three RCTs (flexible rogowski probes) powered from the instruments internal power
supply (left) or split core current transformers with secondary output 333mV (right).
8
