14
|
6.5 CONNECTION OF ALARM CIRCUITS
6.6 INSTALLATION ARRANGEMENT FOR AUSTRALIAN MEN SYSTEMS
The SRF secondary surge diverters are continuously monitored
and their internal protection status is identified by the green LED
on each phase blue secondary Unit (SRFSUAC for phase 1, and
SRFSU on phases 2 and 3 if present).
Reduction in surge handling capacity activates a set of voltage
free alarm contacts which can be used to shut down the load or
to activate an external warning.
When mains voltage is applied to the SRF and the surge
diverters are fully functional, the alarm contacts will be in the
energized or normal state. The NC contact will be in short circuit
with the COM contact. Should the surge handling capacity
fall to below the alarm threshold, these contacts will be in the
de-energised or alarm state and the NO contact will be in short
circuit with the COM contact.
The contacts are "Fail-Safe ' in that, if power to the unit fails, the
contacts will revert to the de-energised or alarm state.
The alarm contacts should only be connected by an
appropriately qualified person owing to the possibility of mains
voltage being present in the SRF cabinet. Care should be taken
to route the alarm wiring away from the input circuit and any
other current-carrying conductors.
Alarm contact ratings:
• 5A
@
250VAC
• 54 @ 30 VDC
• 4kV Isolation
See section 7 "Servicing and Trouble Shooting " for further
information.
Under Australian Standards classification, SRFs are considered
a piece of equipment to be connected to the mains supply. They
are not intended for use as switchboards, distribution boards or
other equipment. As these devices are classified as "electrical
equipment AS 3000 Wiring Regulations apply to the installation
and operation of the units.
AS 3000 specifies minimum requirements for electrical
equipment that is connected to switch boards or distribution
boards. For a point of entry application in the multiple earth
neutral (MEN) distribution system, the SRF equipment should
be installed as close as possible after the MEN point and after
both the main disconnect switch/over-current protector and any
metering equipment. The SRF therefore, may not be installed at
the physical "point of entry " of the mains power to the building.
It must be earthed and installed in accordance with all other
applicable electrical and safety standards. As the protection
equipment is hardwired, the installation must be inspected by
an appropriately authorized electrical authority official prior
to commissioning.
Figure 12. Typical connection detail for SRF point of entry installation in MEN system.
Installation and Operating Instructions