6730S MK (ELECTRIC), 6730S Datasheet - Page 2

• Manufacturer Part Number: 6730S
• Description: RCD, 32A
• Manufacturer: MK (ELECTRIC)
• Series: SENTRYr

Specifications of 6730S

• No. Of Poles: 2
• Voltage Rating Vac: 230V
• Svhc: No SVHC (18-Jun-2010)
• Approval Bodies: BS EN61008, IEE
• Cross-section Area Max: 35mm2
• Current Rating: 32A
• External Depth: 76mm
• External Length / Height: 81mm
• External Width: 36mm

TECHNICAL DATA SHEET
Sentry
Residual Current Devices
(RCDs)
2:5
Standards and approvals
All Sentry RCDs are designed to fully comply with
the requirements of BS EN 61008: 1995.
They all feature positive contact status indication in
accordance with 16th edition IEE Wiring Regulations
(537-02-03 and 537-03-02).
©2001 MK Electric Limited The Arnold Centre, Paycocke Road, Basildon, Essex SS14 3EA, United Kingdom Tel: [phone] Fax: [phone] email: [e-mail] www.mkelectric.co.uk
TECHNICAL SPECIFICATION
Electrical
Rated making and breaking capacity:
Normal (/m) 630A (16 - 63A) and
residual (/ m) 800A (80 - 100A)
Rated conditional short-circuit current:
Normal (/nc) 10,000A and
residual (/ m) 80A Fuse (16 - 40A)
100A Fuse (63 - 100A)
Fault breaking capacity:
3,000A
When used in conjunction with a Sentry MCB, the RCD
will withstand fault current up to the breaking capacity
of the MCB, i.e. 6,000A.
When backed up by a BS 88 fuse, then the breaking
capacity of the RCD is increased to 10,000A.
Operating frequency:
50Hz
Operating voltages:
2 pole devices, 100V and 230V
4 pole devices, 230V to 400V
Physical
Ambient operating temperature:
a.c.: –5°C to +60°C
d.c.: –25°C to +60°C
IP rating:
Front face IP4X, screw IP2X
Max. installation altitude:
2000 metres
Application
The choice of the most suitable RCD for a par-
ticular application should take into account
the following considerations:
1. Sensitivity
— 10mA RCDs offer a high degree of
— 30mA RCDs offer a high degree of
— 100mA RCDs may, in some circumstances,
— 300mA RCDs provide protection against
It is important to note that a current of less
than 500mA flowing in a high resistance
path is sufficient to bring metallic parts to
incandescence and, potentially, initiate a fire.
2. Requirements of the IEE Wiring
Regulations
RCDs may be used to provide additional
protection against both Indirect and Direct
Contact.
The 10mA and 30mA RCDs are the only RCD
sensitivities acceptable under the 16th Edi-
tion Wiring Regulations for direct contact
protection.
— Indirect Contact
Defined as the “contact of persons or livestock
with exposed conductive parts made live by a
fault and which may result in electric shock”.
Effective earthing in conjunction with
automatic disconnection should always be
employed to protect against the effects of
protection against electrocution in an
accidental shock hazard situation. They are
of particular value in a high risk area where
resistances external to the body are likely to
restrict the earth fault current flowing
through the body to less than 30mA and
where 110V supply is being used.
protection in an accidental shock hazard
situation and are by far the most popular
sensitivity used in the United Kingdom. In
a shock situation, the current flowing
through the human body at 240V 50Hz
could be between 80 and 240mA,
depending on the resistance of the body
in question. To ensure that there are no
harmful physiological effects in such a
situation, it is necessary for the RCD to
operate within 300mS at 30mA and 40mS
at 150mA. As the Sentry RCD typically
operates well below these times, it clearly
more than satisfies this requirement.
provide protection against electrocution in
an accidental shock hazard situation,
however, it is important to note that there
is a likelihood that the earth fault current
may be below the sensitivity of the RCD.
This
additional resistances to that of the
human body are in the current path.
the risk of fire only. They do not provide
protection against electrocution in an
accidental shock hazard situation. A
typical application would be lighting
circuits where it is deemed that the risk of
electric shock is small.
becomes
increasingly
likely
if
indirect contact. The provision of a low
resistance path back to the supply from the
fault should ensure that the overcurrent
device operates before damage occurs. This
is the earth fault loop impedance.
In circumstances where the earth fault loop
impedance in the circuit is too high to ensure
operation of the overcurrent device, then the
IEE Wiring Regulations allow the installation
of an RCD. To comply with the Regulations,
the earth loop impedance of the circuit (in
ohms), multiplied by the rated tripping
current of the RCD (in amperes) must not
produce a value greater than 50. With this in
mind, the maximum values of earth loop
impedance permissible when installing an
MK Sentry RCD are as follows:
Z3 (max) = ——– = ——– = 1666 ohms
Rated Tripping
Current of RCD
10mA
30mA
100mA
300mA
(Regulations 413-02-15 and 16 apply). RCDs
are further specified for protection against
indirect contact on TT systems. (Regulations
413-02-19 and 20 apply.)
— Direct Contact
Defined as “contact of persons or livestock with
live parts which may result in electric shock”.
The Regulations recognises four main means
of providing protection against direct contact
which include enclosures and the use of extra
low voltage systems.
However, the use of RCDs is specified by the
regulations in the following instances:
G A socket outlet rated at 32A or less which
may reasonably be expected to supply port-
able equipment for use outdoors shall be
protected by an RCD having the charac-
teristics specified in Regulation 412-06-02.
(Regulation 471-16-01 applies.)
G Where socket outlets are used to supply
caravans on caravan sites, then they must be
protected by an RCD having the charac-
teristics specified in Regulation 412-06-02.
Although RCDs must never be used as the sole
method of direct contact protection, they are
invaluable in providing supplementary pro-
tection in high risk environments where
damage may occur. Typical applications in-
clude situations where equipment may be
used outside or fed by trailing sockets, equip-
ment accessible to children or equipment
used in wet areas. Fore these reasons RCDs are
commonly found in schools, hospitals and
residential installations.
lo n
50
Maximum Permissible
Earth Fault Loop
Impedance
5000 ohms
1666 ohms
500 ohms
166 ohms
0.03
50
Edition 07-01