System Manual Oxford Instruments Plasma Technology OIPT Systems
Int
ernational standard IEC950, section 5.2, requires that a label is attached at the point
where the system is connected to the factory electricity supply: either to the safety
isolation box, or to the transformer, or to the electrical supply outlet socket. This label
must contain the following text:
“WARNING.
High leakage current.
Earth connection essential before connecting supply."
3.1.2 Neutral supply bonding
WARNING
THE NEUTRAL CONDUCTOR MUST BE BONDED TO THE EARTH (GROUND) CONDUCTOR.
IF THIS IS NOT DONE ALREADY IN THE FACTORY SUPPLY, THEN IT MUST BE DONE AT
THE SAFETY ISOLATION BOX AS SHOWN IN Fig 3.1. IF AN ISOLATING TRANSFORMER IS
FITTED, THEN THE NEUTRAL CONDUCTOR OF THE TRANSFORMER SECONDARY MUST
BE BONDED TO THE EARTH (GROUND) CONDUCTOR.
3.1.3 Residual Current Circuit Breakers
Customers sometimes wish to fit a Residual Current Circuit Breaker (RCCB), also known as
an Earth Leakage Circuit Breaker (ELCB, or ELB) to the electrical supply to the system. This
is not recommended for this type of equipment, and a 30mA breaker is likely to trip
often, due to the leakage caused by the filters on the power lines. This leakage is in
accordance with International standard IEC950 section 5.2.
a) If you must fit an ELB, we strongly recommend a minimum current of 100mA.
b) Even a 100mA circuit breaker may trip, and we accept no responsibility if this
turns out to be the case.
3.2 Mandatory Specifications for electrical installations
• Connection: In accordance with local regulations via a safety isolation box,
lockable in the OFF position, mounted adjacent to the machine.
• Configuration: 3-phase, star ("Y") with a grounded neutral supply connected to
the centre point. An independent earth (ground) is required.
• Maximum
Current:
The Maximum Current required by the system is given in the
relevant system installation data sheets.
• Voltage &
Frequency:
380V -10% to 415V +6% or 208V +/-10% phase-to-phase.
Frequency to be 50Hz or 60Hz. Note that voltage and frequency
cannot be changed from the values specified at the time of
ordering.
• Safety Earthing: The system safety earthing must be in accordance with local
Electrical Regulations. See Fig 3.1.
4. Compressed air
A dry and clean compressed air supply at a minimum pressure of 6 bar (90 psig) must be
fed to a customer-supplied air filter/mist separator/pressure regulator unit mounted
Services Specifications
Printed: 6-Jan-10, 8:53 Page 11 of 22 Issue 21: January 10
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