Residual Current
Circuit Breakers
RCCB
B
C
Contents
General Information..............................................................
24
Application............................................................................
24
How To Identify An RCCB From Its Markings...........................
24
Technical Specifications.......................................................
26
Working Principle...................................................................
27
Protection Against Hazardous Shock Currents........................
27
Protective Action...................................................................
28
The Installations Standards.....................................................
29
Selective Tripping..................................................................
29
Protection Against Transient Currents............................................ 30
Precautions................................................................................. 31
31
Dimensions............................................................................
32
Order Information.................................................................
33
R
C
Circuit Connection................................................................
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1
RCCB
Residual Current
Circuit Breakers
General Information
Sigma RCCB’s are designed to protect equipment and people from
low level ground faults. Typical applications include resistance and
impedance heating systems; submersible pumps; semiconductor process equipment and wet location equipment.
The RCCBs use the residual current sensing method to detect ground
faults. The units monitor the load currents and will trip immediately
should they detect any imbalance greater than the rated trip level.
Sigma RCCB’s derive the energy required to trip from the ground fault
current alone. They will operate normally even if the system voltage
drops or if the neutral wire is disconnected. They will also operate
normally during long periods of over voltage.
Application
Sensitivity
Application
30mA
Tripping current designed for additional protection against direct contact, the 30 mA RCCB protects against leakage currents and
indirect contact with earth loop impedance up to 167 ohms; for use as additional protection against direct contact, residual tripping
current must not exceed 30 mA.
300mA
A lees sensitive protection suitable for large installations having high levels of leakage current: 300 mA RCCB’s protect against
leakage current and indirect contact up to 167 ohms earth loop impedance
How To Identify An RCCB From Its Markings
Test button
Rated conditional
short-circuit current
On-Off indicator
Rated current
Rated Residual Current
Lowest operational
Ambient Temperature
Rated residual current IΔn is the value of residual current
IΔ specified by the manufacturer at which the residual
current circuit breaker must switch out under specified
conditions. Alternating residual current must release the
residual current circuit breaker within (0.5 ÷ 1) IΔn
Rated current In is the value of current specified by the
manufacturer, which can be transferred by the residual
current circuit breaker continuously. So the current In can
pass through the contacts for an unlimited time. Therefore
it is, for instance, possible to use a residual current circuit
breaker with In = 25 A in 16 A circuit.
Ambient temperature T for the residual current circuit breakers is (-5 ÷ +40) °C according to almost all international
standards. Some residual current circuit breakers work in an extended range (-25 ÷ +40) °C. This possibility is identified by the following symbol on the
rating plate.
Rated operating voltage Ue is the voltage the residual current circuit breaker is to be connected to and which properties are related to. The connected
voltage has no effect on the device function but on the function of the test circuit and isolation properties.
Rated frequency fn is the frequency the residual current circuit breaker is designed for and at which it works correctly under stated conditions. Majority of residual current circuit breakers are designed for fn = 50 to 60 Hz. As the residual current circuit breaker function is based on the induction
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Residual Current
Circuit Breakers
RCCB
principle, the residual current behaviour and frequency show an effect upon tripping. When using a device designed for 50/60 Hz in a network with a
different frequency, the user must count on a change of the tripping threshold i.e. a change of IΔn
Rated conditional short-circuit current Inc – short-circuit strength. The function and design principle does not allow for the residual current circuit
breaker use for protection against short-circuit. For circuit protection it is necessary to use a circuit breaker or a fuse. These elements cut the shortcircuited circuit safely off . The residual current circuit breaker must only withstand the through-going short-circuit current. The amplitude of the
maximum through current is defined as rated conditional short-circuit current Inc. The short-circuit strength is then expressed by the current Inc. For
example, on the rating plate, Inc = 10 kA is expressed by the following symbol:
Residual current circuit breaker – type AC – reacts to sine-wave residual current – it is used in conventional AC networks.
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Residual Current
Circuit Breakers
RCCB
Technical Specifications
Type
SGM-2
SGM-4
SHM-2
SHM-4
SDM-2
SDM-4
No of Poles
2
4
2
4
2
4
Rated Current
In
A
25, 40, 63
25, 40, 63, 80, 100
Rated Residual Current
I∆n
mA
30, 300
30, 300
Hz
50-60
50-60
Rated Frequency
Current Sensitivity
AC
AC
AC
Tripping Time
s
< 0.3
< 0.3
0.13<t<0.5
Delay Time
ms
Without Delay
Without Delay
min. 130
240
240
Rated Voltage
Ue
V
Rated Inslutaled Voltage
Ui
V
660
660
Rated Impulse Voltage
Uimp
kV
6
6
A
10000
6000
4000
4000
20000
20000
IP 20 (IP 40)
IP 20 (IP 40)
Rated Short-Circuit Withstand Current
(With NH Fuses)
Electrical Life
ope.
Mechanical Life
ope.
V
Degree Of Protection (After Assembly)
AC
230
415
415
240
Ambient Operational Temperature
o
C
-25 / +40
-25 / +40
Storage Temperature
o
C
-40 / +55
-40 / +55
Dimensions
W
mm
H
mm
70
35
70
35
80
83
Colour
RAL 7035
RAL 7035
Assembly Way (EN 60715)
35 mm DIN rail
35 mm DIN rail
1.5 - 35
1.5 - 35
Connection Capacity (Min./Max)
mm2
Weight
gr
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35
194
334
203
339
203
415
70
339
Residual Current
Circuit Breakers
RCCB
Working Principle
RCCB works on the principle that in an electrical circuit the incoming current
is the same as out going current as shown in the diagram. RCCB incorporates a core balance transformer having primary and secondary windings
and a sensitive relay for instantaneous detection of fault signal. The primary
winding lies in series with the supply mains and load. Secondary winding is
connected to a very sensitive relay. In a faultless situtation, the magnetized
effects of the current carrying conductors cancel each other out. There is no
residual magnetic field that could induce a voltage in the secondary. During
flow of leakage current in the circuit an imbalance is created in the circuit
which gives rise to leakage flux in the core. This leakage flux generates and
electrical signal that is sensed by the relay and it trips the mechanism thereby disconnecting the supply.
When pressing the TEST button ‘T’, a fault is simulated via the test
resistance & RCCB trips.
The structure of electro mechanical RCCB
Protection against hazardous shock currents
Application
• Protection against indirect contact (indirect personnel protection). Protection is provided by disconnecting hazardous high touch voltages caused by a short
circuit to exposed conductive parts of equipment.
• When using RCCBs with I∆n ≤ 30 mA, protection from direct contact (direct personnel protection) is also provided. Supplementary protection measure by
disconnection when live parts are touched.
Current ranges acc. to IEC 479
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RCCB
Residual Current
Circuit Breakers
Protective Action
While RCCBs for rated fault current I∆n > 30 mA provide protection against indirect contact, the installation of RCCBs with I∆n ≤ 30 mA provides a high
level of additional protection against unintentional direct contact with live parts. The above diagram shows the physiological responses in the human
body when current flows through it, classified into current ranges. Current/time values in range 4 are dangerous, as they can initiate heart fibrillation
which can result in death. The tripping range for RCCBs with rated fault currents of 10 mA and 30 mA is also indicated. On the average, the release time
lies between 10 ms and 30 ms. The permissible release time, according to EN 61 008 of max. 0.2 s (200 ms) or 0.3 s (300 ms) is not reached.
Thus, RCCBs with rated fault currents of 10 mA or 30 mA provide reliable protection even if a current flows through a person as a result of unintentional
direct contact with live parts. This level
of protection cannot be achieved by any
other comparable means of protection against indirect contact. Wherever
RCCBs are used, an appropriate protective ground conductor must also be provided and connected to all of the equipment and parts of the system. Thus, a
current can only flow through a human
body if two faults are present or if the
person accidentally touches live parts.
Examples for unintentional direct contact
If a person directly touches live parts, two resistances determine the level of the current
flowing through the human body, i.e. the
internal resistance of the person RM and the
local ground leakage resistance RSt. For the
purpose of accident prevention, the worst
case must be assumed which means that
the local ground leakage resistance is almost
zero. The resistance of the human body is
dependent on the current path. For example,
measurements have shown for a hand-tohand or hand-to-foot path, a resistance of
approximately 1000 W.
I M:
Shock current
R M : Internal resistance of
human beings
R St : Standard ground leakage
resistance
R A : Grounding resistance of
all conductive parts
exposed to the grounding electrodes
For 230 V AC fault voltage, this results in a
current of 230 mA for the hand-to-hand path.
Schematic drawing: Additional protection when directly touching live parts
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Residual Current
Circuit Breakers
RCCB
The Installations Standards
RCCBs may be used in all three distribution network types (DIN VDE 0100 Part 410) and in an IT network system provided that the capacity of the network to ground is sufficient to allow a fault current to flow which has the same level as the rated fault current. The IT network can still be monitored
using an insulation monitor. Both protective systems do not mutually interfere with one another.
Selective Tripping
Residual current operated circuit-breakers normally have an instantaneous release. This means that a series connection of such residual current operated circuit-breakers with the aim to provide selective tripping will not operate correctly when a fault occurs. To achieve selectivity when RCCBs are
connected in series, the devices connected in series must be graded both with regard to the release time as well as with regard to the rated fault current. Selective RCCBs have a tripping delay.
Selective RCCBs have the symbol
S
.
The table opposite shows a possible grading of RCCBs for selective tripping when the RCCBs are connected in series without time delay.
Main
distribution
board
Sub distribution
board
RCCB
RCCB
S
Selective version
RCCB
For undelayed
disconnection
undelayed
n = 300 mA
10 mA or 30 mA
= 500 mA
10 mA or 30 mA
n = 1000 mA
10 mA or 30 mA
n
0,3; 0,5
AI2_06168d
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Residual Current
Circuit Breakers
RCCB
I∆n1= 300mA
I∆n2= 30mA
(ms)
1000
S
G
500
500
300
300
200
150
130
Tripping time
100
60
40
150
150
50
40
40
S
Delayed type
40
G
10
10
10
10
10
Without delay type
Undesired tripping
region
Tripping time span
Her iki anahtar üstte:
1
10
15
30
60
I∆n2
2I∆n2
100
150
5I∆n2
200
300
600
I∆n1
2I∆n1
I∆n1
I∆n2
Type
In (A)
I∆n (A)
General
(Instantaneous)
All Values
All Values
Selective
>25
>0,030
1500 (mA)
500A
I∆n
5I∆n1
Rated residual current values for delayed
type
Rated residual current values for without
delayed type
Standardised Value Of Operating And Non-Operating Times (in seconds) At:
I∆n (A)
I∆n (A)
2 I∆n (A)
500 A
0,3
0,15
0,04
0,04
Max. Operating time
0,5
0,2
0,15
0,15
Max. Operating time
0,13
0,06
0,05
0,04
Min. Operating time
Protection Against Transient Currents
In order to avoid nuisance tripping (unwanted tripping due to an impulse voltage) due to lightning surges, switching on high capacitance circuits and
switching surges, Rcd's series have a high level of immunity to transient currents.
Type A, AC..............................................................250 A 8/20µ
Type S, AC.............................................................3000 A 8/20µ
Transient current at 250A (peak current) at point on wave 8/20ms
(VDE 0664)
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Transient current at 200A (peak current) at minimised point on wave
0.5ms-100kHz (pr EN 61.1008)
Residual Current
Circuit Breakers
RCCB
Precautions
•
Wiring should be done by a trained & qualified electrician as per the wiring diagram.
•
All wiring necessary for operation shall be passed through the RCCB.
•
The neutral conductor must be insulated against earth to the same extent as the live conductors.
•
All equipments used must be properly earthed.
•
To ensure correct functioning care must be taken that the neutral conductor on the load side of the RCCB must not be connected to earth, otherwise
nuisance tripping may occur or tripping may be impaired.
•
Suitable device either MCB or HRC fuses shall be used for short circuit and overload protection of the circuit under installation.
•
Don’t expose the circuit breaker to direct sunlight, rough weather and keep it away from the influence of magnetic field.
Circuit Connection
2 poles RCCB
4 poles RCCB
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RCCB
Residual Current
Circuit Breakers
Dimensions
SGM-2 / SGM-4
SGM-2 / SGM-4
SHM-2 / SHM-4 / SDM-2/ SDM-4
SHM-2 / SHM-4 / SDM-2 / SDM-4
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32
SHM-
Residual Current
Circuit Breakers
RCCB
Order Informations
2P 30 mA 6 kA RCCB's
4P 300 mA 6 kA RCCB's
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
SHM-2
2
25
30
SHM2025030
SHM-4
4
25
300
SHM4025300
SHM-2
2
40
30
SHM2040030
SHM-4
4
40
300
SHM4040300
SHM-2
2
63
30
SHM2063030
SHM-4
4
63
300
SHM4063300
SHM-4
4
80
300
SHM4080300
SHM-4
4
100
300
SHM4100300
2P 300 mA 6 kA RCCB's
2P 300 mA 6 kA selective type RCCB's
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
SHM-2
2
25
300
SHM2025300
SDM-2
2
25
300
SDM2025300
SHM-2
2
40
300
SHM2040300
SDM-2
2
40
300
SDM2040300
SHM-2
2
63
300
SHM2063300
SDM-2
2
63
300
SDM2063300
SHM-2
2
80
300
SHM2080300
SDM-2
2
80
300
SDM2080300
4P 30 mA 6 kA RCCB's
4P 300 mA 6 kA selective type RCCB's
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
Type
Code
No Of
Poles
Rated
Current
(In) A
Rated Residual
Current
IΔn (mA)
Order code
SHM-4
4
25
30
SHM4025030
SDM-4
4
25
300
SDM4025300
SHM-4
4
40
30
SHM4040030
SDM-4
4
40
300
SDM4040300
SHM-4
4
63
30
SHM4063030
SDM-4
4
63
300
SDM4063300
SHM-4
4
80
30
SHM4080030
SDM-4
4
80
300
SDM4080300
SHM-4
4
100
30
SHM4100030
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Residual Current
Circuit Breakers
RCCB
2P 30 mA 10 kA RCCB's
Type
Code
No Of
Poles
Rated Current Rated Residual Current
(In) A
IΔn (mA)
SGM-2
2
25
30
SGM2025030
SGM-2
2
40
30
SGM2040030
SGM-2
2
63
30
SGM2063030
Order code
2P 300 mA 10 kA RCCB's
Type
Code
No Of
Poles
Rated Current Rated Residual Current
(In) A
IΔn (mA)
SGM-2
2
25
300
SGM2025300
SGM-2
2
40
300
SGM2040300
SGM-2
2
63
300
SGM2063300
Order code
4P 30 mA 10 kA RCCB's
Type
Code
No Of
Poles
Rated Current Rated Residual Current
( In) A
IΔn (mA)
SGM-4
4
25
30
SGM4025030
SGM-4
4
40
30
SGM4040030
SGM-4
4
63
30
SGM4063030
Order code
4P 300 mA 10 kA RCCB's
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Rated Current Rated Residual Current
( In) A
IΔn (mA)
Type
Code
No Of
Poles
SGM-4
4
25
300
SGM4025300
SGM-4
4
40
300
SGM4040300
SGM-4
4
63
300
SGM4063300
Order code
QUALITY CERTIFICATES
ISO 9001:2008
Do not risk your safety!
Ekşioğlu Mah. Yeni Şile Cad. No:40 34794 Alemdağ - Çekmeköy / İstanbul / TURKEY
Tel: +90 216 429 72 01 (pbx) Fax: +90 216 484 41 01
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sigma@sigmaelektrik.com