5.4 Electrical Installation Information
The IPD Integrated Protection Relay is a microprocessor based protection relay that has the facility for
connecting intrinsically safe remote monitoring equipment. This can be in the form of either the Remote
Display Module or other peripheral equipment such as PLC’s.
These instructions have been designed to assist users of the IPD Relay with installation and special
wiring techniques required maintaining the integrity of the intrinsically safe circuits.
The connections to the IPD Relay consist of a mix of intrinsically safe circuits through to “high” voltage
supplies and relay contact circuits. To ensure the integrity of the intrinsic safety is maintained and to reduce
induction from high voltages, care needs to be taken in the layout of the wiring and the installation.
For installations on high voltage systems (>3.3kV) it is advisable to install a power supply filter, e.g.
Schaffner FN612-1106 (1A, 250VAC chassis mounted filter) adjacent to the IPD Relay. The earth should be
connected to Pin 7 on the relay as directly as possible.
The IPD Relay’s approval requires that the relay is installed in accordance with the Australian Standard for
Intrinsic Safety Installation AS/NZS 60079.14. This makes it necessary for anyone installing IPD Relays to
be familiar with, and have a good understanding of, AS/NZS 60079.14.
The IPD Integrated Protection Relay is typically installed into a system along with appropriate devices
providing input signals (sensors) and output control, per IPDE001. The following information should be
considered in conjunction with this typical installation drawing.
5.4.1 Earthing
The IPD must be infallibly connected to the main system earth via the three earth terminal provided on
pins 2, 7 and 12. To maintain the intrinsically safe properties of the relay it is vital that the earth pins 2,
7 and 12 are all individually connected with a minimum earth conductor size of 1.5mm
2
. The intrinsic
safety circuits have been tested to IEC60079.11 and require at least three independent connecting
elements for ‘ia’ circuits to maintain the intrinsic safety properties. These three earth connections shall
be connected in parallel back to the main earth point and are not to be connected in series.
The IKD interface must be infallibly connected to the main system earth via at least one of the earthed
mounting bolts on the chassis.
The earth on pin 29 connects to the earth shield of the IPD Relay’s internal transformer. This earth is a
protection earth and is not an intrinsic safety earth.
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