Residual Current is a critical condition impacting hospitals, data centres, industrial plants, etc. It can lead to dangerous situations for both personnel and equipment. Moreover, it can cause unexpected interruptions, malfunctions and EMC problems that cost time and money. Hence, Residual Current Monitoring is critical for safety, high availability and productivity in industrial and purpose-built environments. Inside environments like data centres where shielded cables are present, residual current may spread through cable shielding across different parts of the data centre if the racks are insufficiently earthed. This can lead to fires, unexplained IT systems failures, tripping and disconnecting of critical equipment.

2. RESIDUAL CURRENT MONITORING (RCM)
PREVENT ELECTRICAL FIRE & HAZARDS
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• What is Residual Current and why
you should care
• Types of Residual Current Monitoring
• Residual Current Monitoring Devices
• Janitza APPs and software for RCM
CONTENTS

4. • Insulation Failures
• Bad Practices
• Unsafe Environment
REASONS
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5. • Electrical current that occurs in an unwanted
conductive path
• It flows from either AC or DC circuit in
equipment to the chassis, or to the ground
• Residual currents are typically the result of
insulation faults, defective equipment and
components (power supplies, electrical loads)
causing outflow-related residual currents and
stray currents in TN-S systems
• RCM classification is based on frequency
and waveform of the current that they can
detect - Type A, Type B, Type B+
WHAT IS RESIDUAL CURRENT?
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6. Ensure Continuous System Availability
In Market segments with sensitive applications (e.g.,
Critical power locations, Hospitals, Industrial
Manufacturing), an uninterrupted power system is of
crucial importance.
• Uninterrupted operation (Increased Uptime &
Availability) of an installation is only ensured by
continuous monitoring.
• Continuous Residual Current Monitoring is the only
method to detect dangerous fault currents at an early
stage, thereby avoiding damage to the power system as
well as preventing server or production downtimes.
• RCM measurement in accordance with DIN EN 62020
offers the most reliable and safe alternative wherever the
realization of Insulation Resistance Measurement or
RCDs are not practical in an installation.
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WHY TO USE RCM
(EARTH LEAKAGE MONITORING)?
Alarm Notification of Leakage Current helps pre-empt Breaker
Tripping

7. • Electric Shock
• Breaker Tripping
• Fire Hazard
• Server and Computer Shutdown
• Interruption of Communication Networks
• Temperature Rise in Conductors resulting
in Insulation Breakdown
• Fast Corrosion of Metal Pipes
• Production Shutdown
• VSD / Inverter Faults
• Sensor Malfunction
• Overvoltage Problems
• Overloaded Neutral Conductor
Data Centre Fire Damage
Overloaded N Conductor
Corrosion in Pipes caused by Leakage Current Damage to the insulation
PROBLEMS CAUSED BY
FAULT CURRENTS
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8. • Natural deterioration due to aging
• Accelerated by excessive heat and moisture
• Heat, moisture and dirt are main causes of
insulation failure
• Chemical deterioration
• Mechanical damage
• Sunlight
• Excessive voltage stresses
INSULATION FAILURE-REASONS

9. RCM - HOW IT WORKS?
Fault Current ≈ 0
System = OK
Sum >> 0
Failure in the
electrical system
• Conductors (L1, L2, L3, N) of the specific measurement
point are to be monitored and passed through the RCM CT
• In a fault-free system the sum of all currents is ZERO, so
that in the current transformer no current is induced.
• If a fault current is flowing, the current difference induces
in the differential CT a mA current that is detected by our
UMG device
• Residual currents are typically the result of insulation faults,
defective equipment and components (power supplies,
electrical loads)

10. RCM CT

11. RCM INSTALLATIONS
Main Incomer Busbar
RCM CT

12. RCM INSTALLATIONS
RCM CT
Sub Circuits DB

13. RCM INSTALLATIONS
RCM CT
Sub Circuits DB

14. RCM INSTALLATIONS
RCM CT
Single Phase Circuits Server Rack

15. TYPES OF RCM
TYPE B+
TYPE B
TYPE A
Sinusoidal alternating current pulsed
direct current
Smooth & pulsating direct current as well as
alternating currents upto 2 kHz.
Smooth & pulsating direct current as well as
alternating currents upto 20 kHz.

16. TYPES OF RESIDUAL CURRENT

17. • Verification Standard IEC 60364-6;
NEW! Revision… Edition 2.0 2016-04
• When RCM (Earth Leakage Monitoring) is
installed and operational, there is “NO”
requirement for Mains Power disconnection
• Confirmation of correct rating and setting of
monitoring devices
Where a circuit is permanently monitored by
an RCM in accordance with IEC 62020 or an
IMD in accordance with IEC 61557-8, it is
not necessary to measure the insulation
resistance if the functioning of the IMD or
RCM is correct.
RCM STANDARDS
• The functioning of the RCM or IMD shall be verified.
INTERNATIONAL STANDARD
• Low Voltage electrical installations –
Part 6: Verification

18. Insulation Testing as part of Preventive Maintenance
• Both the ends of the cable need to be disconnected and then
meggered for finding the insulation
• Long testing times results in long shutdown times
• Cumbersome procedure of disconnecting the terminated cables
• Periodicity of the tests needs long term planning as well
Insulation Monitors - Online
• A popular measuring method is to superimpose a measuring DC
voltage between the phase and PE conductor
• This measurement procedure is suitable for monitoring
conventional AC, 3(N)AC systems. If it is used in AC, 3(N)AC
systems containing galvanically connected DC components, these
DC currents will distort the measurement result.
• Cost prohibitive
Residual Current Breakers / Earth
Leakage Relays
• Trip the circuit causing incidents
• Tripping is a surprise factor in the
Facility
• No Prediction only Prevention of
major fire
ALTERNATIVE FOR RESIDUAL
CURRENT MONITORING

19. BENEFITS OF RESIDUAL CURRENT MONITORING
AVOID SYSTEM
FAILURES
MAINTENANCE COST
OPTIMIZATION
SIGNALING
INSTEAD OF
SHUTDOWN
PREVENT
PRODUCTION
INTERRUPTIONS
IMPROVE FIRE
PROTECTION
MONITOR HIGHLY
AVAILABLE ENERGY
DISTRIBUTION SYSTEMS

20. RCM – WHERE IS IT USED?
APPLICATIONS
• Industrial Manufacturing
• Data Centre & Critical Power Applications
• Power Distribution Busbar
• Rail Networks
• TN-S Systems
• Drive Systems (Frequency Converters)
• DC Applications
• Hospital & Medical Facilities

21. LV Main
Distribution
Switchboard
Chiller Plants
Sub-Distribution
Switchboards,
UPS Outputs
PDU, Critical Power
Supply Points &
Busway Feed Box
Out-going Circuits,
Final Sub-
Measurement &
Busway Tap-Offs
MV & LV Supply
(PCC)
UMG 512-PRO UMG 509-PRO UMG 801 UMG 96-PA UMG 96RM-E UMG 96RM-PN RCM 202-AB RCM 201-
ROGO
UMG 20-CM
FROM UTILITY INCOMER TO THE FINAL CIRCUIT – OUR RCM DEVICES

22. UMG 512 PRO CLASS A PQM UMG 509 PRO UMG 96 RM-E UMG 96 RM-PN
TYPE A RCM DEVICES

23. UMG 96 PA
(with RCM module)
UMG 806 RCM 201-ROGO
TYPE A RCM DEVICES

24. UMG 20 CM RCM 202 AB
TYPE A RCM DEVICES

25. UMG 96 RM-E UMG 96 PA
(with RCM module)
RCM 202 AB
UMG 96 PQ-L
(with RCM module)
TYPE B RCM DEVICES

26. UMG 96 PA
(with RCM module)
UMG 96 PQ-L
(with RCM module)
RCM 202 AB
TYPE B+ RCM DEVICES

27. RCM 202-AB
• Two-channel RCM device for measurement and
monitoring according to the IEC 62020 standard
• Comprehensive analytical tools
• Up to a maximum residual current of 20 A
• Measurement and monitoring of AC/DC residual
currents type A/B/B+ in TN and TT systems (grounded
AC systems)
• Warning and alarm thresholds configurable for each
channel separately
• RS 485 interface (Modbus)
• Two digital outputs
• Two analogue outputs (interfaces 4 … 20 mA)
• Harmonics up to 20 kHz (Type B+)

28. GridVis-RCM REPORT
• Analyze and evaluate residual current violations with the
GridVis RCM report
• Receive statistics regarding threshold violations with
graphically highlighted overviews
• Setting of up to 4 threshold levels
• Support of dynamic thresholds (RCM measuring device
configuration!)
• Custom text, customer logo and export in PDF and XLS
format
• Report creation can be carried out at custom time schedule
• Automatically dispatch per E-Mail

29. RCM ANALYSIS APP
• APP with extensive options for setting limit values and
analyzing fault currents in detail
• Up to 20 RCM channels can be managed and
evaluated via a gateway
• The evaluation covers all types of residual current
with an associated frequency analysis
• For example, 50 Hz, pure DC or high-frequency
residual currents in the 20 kHz range can be displayed
individually
• In addition, the application enables the proven
dynamic limit value formation with Janitza energy
measuring devices
• Energy measuring devices can be assigned to each of
the 20 RCM channels and limit values can be
calculated as a function of power

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Contact us
MESSUNG SYSTEMS PVT. LTD.
501, 502 & 503 Lunkad Sky Vista, Viman Nagar, Pune, India - 411 014.
+91 20 6649 2800 | info@messung.com
THANK YOU