Sonel MPI-540 - Additional accessories

MPI-540 – USER MANUAL
186
Additional uncertainty caused by serial interference voltage for 3p, 4p, 3p+clamps functions
(for 25 V and 50 V)
R
E
Additional uncertainty
<10 Ω
)026,0%100))10131012()10331032(((
3325
4



ZZEZE
UURUR
≥10 Ω
)26,0%100))10191014()1011046(((
5829
4



ZZEZE
UURUR
Additional uncertainty caused by resistance of electrodes
[%]105
1
1103
200
300
10
43
2
6























H
EHE
H
S
S
dod
R
RRR
R
R
R

Formula is valid for R
S
> 200 Ω and/or R
H
≥ 200 Ω.
Additional uncertainty due to interference current for 3p + clamps function
(for 25 V and 50 V)
R
E
Uncertainty [Ω]
≤50
)104(
2
2
zaklE
IR 

>50
)1025(
22
5
zaklE
IR 

Additional uncertainty due to interference current for double clamps function
R
E
Uncertainty [Ω]
<5 Ω
)105(
2
2
zaklE
IR 

≥5 Ω
)105,2(
22
2
zaklE
IR 

Additional uncertainty for the ratio of the resistance measured with clamps on a branch of a
multiple earthing, to the resultant resistance the as a function of 3p + clamps.
R
C
Uncertainty [Ω]
≤99.9 Ω
)105(
2
3
w
C
R
R


> 99.9 Ω
)109(
2
2
w
C
R
R


R
C
[Ω] is a value of resistance measured with clamps on the branch displayed by the device,
whereas R
W
[Ω] is a value of resultant resistance of multiply earthing.
10.4.5 Additional uncertainties according to IEC 61557-6 (RCD)
I
A
, t
A
, U
B
Significant parameter
Designation
Additional uncertainty
Position
E
1
0%
Supply voltage
E
2
0%
Temperature 0°C...35°C
E
3
0%
Resistance of electrodes
E
5
0%
Mains voltage 85%...110% U
n
E
8
0%