Setting Example - Siemens SIPROTEC 5 7UM85 Manual

Setting Example

I-DIFF Fast
(_:11071:3) Threshold = 6.0 I/IrObj
I-DIFF Unrestrained
(_:18002:3) Threshold = 10.0 I/IrObj
Step 2: Overcurrent Protection, Phases
Definite-T 1: (_:662:3) Threshold = 4.5 A
Definite-T 1: (_:662:6) Operate delay = 0.20 s
Definite-T 2: (_:662:3) Threshold = 6.5 A
Definite-T 2: (_:662:6) Operate delay = 0.10 s
Step 3: Protection for the Unbalanced Load
Negative-Sequence Protection
Definite-T 1: (_:1981:3) Threshold = 10 %
with the reference value I
Definite-T 1: (_:1981:6) Operate delay = 50 s
Definite-T 2: (_:1982:3) Threshold = 50 %
with the reference value I
Definite-T 2: (_:1982:6) Operate delay = 1.5 s
If the current is greater than the maximum current limitation of the Negative-sequence protection function,
the Overcurrent protection, ground function can be activated to protect the unbalanced load.
Overcurrent Protection, Ground
Definite-T 1: (_:751:3) Threshold = 0.20 A
Definite-T 1: (_:751:6) Operate delay = 0.00 s
Step 4: Motor-Starting Time Supervision
Inverse-T 1: (_:11551:104) Start.cur./mot.rated cur. =
5.2
Inverse-T 1: (_:11551:102) Max.start.time,cold motor
= 15.0 s
Inverse-T 1: (_:11551:103) Max.str.time, warm motor
= 8.2 s
The motor secondary rated current is calculated as follows:
The motor starting current is calculated as follows:
26 SIPROTEC 5, Additional Information on the Protection of Explosion-Proof Motors with Type of Protection Increased Safety e,
= 1 A
rated
= 1 A
rated
The pickup threshold for the differential current
The pickup threshold for the differential current
The pickup value of the 1st Definite-time overcur-
rent protection stage
The operate delay of the 1st Definite-time overcur-
rent protection stage
The pickup value of the 2nd Definite-time overcur-
rent protection stage
The operate delay of the 2nd Definite-time overcur-
rent protection stage
The pickup value of the 1st Definite-time negative-
sequence protection stage
The operate delay of the 1st Definite-time negative-
sequence protection stage
The pickup value of the 2nd Definite-time negative-
sequence protection stage
The operate delay of the 2nd Definite-time negative-
sequence protection stage
The pickup value of the 1st Definite-time overcur-
rent protection stage
The operate delay of the 1st Definite-time overcur-
rent protection stage
The rated starting-current value which is a per-unit
value with the motor rated current as reference
The rated starting time for the cold rotor state of the
stage with inverse-time characteristic curve
The rated starting time for the warm rotor state of the
stage with inverse-time characteristic curve
C53000-H5050-C078-1, Edition 03.2019
Manual