earthing diagram (ed) benches - schneider electric ... with protection devices based on...
TRANSCRIPT
S.L.T.-XM200 Bench
Study and operate the
protection features
associated with the
neutral plans with manual
troubleshooting
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S.L.T.-XM200 Bench
1. Presentation of the kit
This bench illustrates the rationale underlying the current regulations and standards concerning the physical protection of individuals as regards the TN or TT systems (first working
surface) and the IT system (second working surface).
1.1 Overview
On each of the totally independent surfaces, 3 single or three-phase receivers have been represented, with protection devices based on magneto-thermal circuit-breaker, differential
circuit-breakers, differential switches, contactors.
Power resistors and a rehostat located in the base of the bench are connected to the panel by cables (supplied) fitted with safety jacks for operations under the supervision of a qualified
teacher.
IT system TN or TT systems
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S.L.T.-XM200 Bench
1.2 Characteristics
Mechanical characteristics
Dimensions: height: 1900 mm, width: 770 mm, depth: 600 mm (920 shelves unfolded)
Weight: 152 kg
Electrical characteristics
The bench is powered by a 400 V three-phase electrical network with earth power ≥ 4 kVA.
Voltage: 400 V three-phase ± 10 %
Frequency: 50 Hz ± 5 %
Current: 16 A, connection by 3P + earth socket
The conventional short-circuit current is set to 10 kA.
Rated impulse withstand voltage: 2,5 kV
Protection class: l
The electrical network must be fitted with a RCD (Residual Current Device) of sensitivity ≤ 30 mA of AC class upstream the bench (not supplied).
Technical characteristics of built-in components
Isolation controller
– Vigilohm XM200 380-415V
Transformers
– Transformer 48VA u : 230/400V S : 24 VA
– 2 Star-triangle three phase transformer
Circuit breaker
– Three pole magneto-thermal circuit-breaker 4 to 6,3A
– Two pole magneto-thermal circuit-breaker 1A and 0,5A
– Four pole circuit breaker 16A
– Three pole circuit breaker 10A
– Two pole circuit breaker 12A, 0,5 et 6A
– Differential bipolar circuit breaker 240V 25A 10mA
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S.L.T.-XM200 Bench
1.3 Functional description
The S.L.T. XM200 bench allows the users to perform exercises on the various neutral plans.
The two surfaces may be used at the same time, one for TN and TT neutral plans exercises, the other for the IT neutral plan exercises.
Two single-phase receivers (R1 and R2) and a three-phase receiver have been represented.
It has been assumed, for the sake of clarity and to assist in training, that receivers are in premises of various classes. The R3 receiver is supposed to be installed in fire risk premises.
The user can then perform the various exercises on the two surfaces of the bench as well as on
the power resistors located in the base of the bench.
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S.L.T.-XM200 Bench
2. Teaching
2.1 Teaching presentation
S.L.T. XM200 Bench allows:
Theoretical study of the various neutral plans.
Circuit cabling and study of device responses
On the IT neutral plan: manual troubleshooting system.
It is intended to the following studies:
Professional High School University &
Engineering school
Automated Systems Industrial Computing
Monitoring and Regulation
Electrical Engineering
Engineering Equipment Energy
Industrial Maintenance
Automated Production
Mechanical Industrial Automated Systems
Miscellaneous Industrial Automated Systems
Exercises to be performed from the S.L.T.-TR22 bench:
The exercises are composed of a teacher document and a student document.
TT neutral plan:
– Interconnection and earthing of groundings are necessary conditions but not sufficient to ensure protection.
– The magneto-thermal circuit breakers do not ensure the protection against the indirect contacts.
– The use of a RCD is a necessary condition but not sufficient to ensure protection (threshold selection).
– The use of a RCD is a necessary condition but not sufficient to ensure protection (RA maximum value).
– Selective activation by RCD located at various level.
– The earthing connection values must be measured regularly.
– Fire risk.
– Mobile receivers.
TN neutral plan:
– An earth fault leads to an overcurrent which is eliminated by standard circuit breakers.
– Does a given circuit-breaker ensure protection in every case?
– What to do if the conditions are not fulfilled?
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S.L.T.-XM200 Bench
IT neutral plan:
– Interconnection and earthing of frames are necessary and sufficient conditions for protection in case of a first fault.
– Permanent insulation monitoring of the network with respect to earth and indication of a first fault.
– Single fault: location of faulty feeder by successive opening of the various circuit-breakers.
– Single fault: location of faulty feeder by injecting ac current at very low frequency.
– Single fault: location of faulty feeder by injecting ac current at very low frequency and fixed detectors
– Double fault: full fault on R2 (phase 3) - full fault on R3 (phase 1): need to provide RCDs on long feeders.
– Double fault : full fault on R2 (phase 3) - full fault on R3 (phase 1): circuit-breaker protection are sufficients with protection.
– Single fault: taking into account of the transitions causing transient fault.
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S.L.T.-XM200 Bench
3. Items provided with the kit
3.1 Equipment provided
A ready-to-use S.L.T.-XM200 bench assembly with two double-sided working surface reference MDG99603.
A set of safety cables
3.2 Documentation
A technical manual and exercise book (reference MDG9AD603EN)
4. Contact details
Schneider Electric France Activité Didactique 3F 35 rue Joseph Monier CS 30323 92506 Rueil Malmaison - France “Indigo” phone No.: 0 825 012 999 http://www.schneider-electric.com/educationalequipments e-mail: [email protected]