Portable Earthing Devices
Portable Earthing Devices (portable earths) are personal protective devices which are used to protect electrical workers if the high voltage equipment they are working on is re-energised. In the even that a conductor is energised inadvertently, the aim of a portable earth is to:
• Provide a controlled path for the short circuit current away from an exposed worker to allow short circuit detection equipment to operate and disconnect supply quickly, and
• To minimise the voltage rise and reduce the chance of electric shock occurring.
In Australia and New Zealand, portable earths must be used when working on high voltage (>1000V) networks. They are not generally required for work on low voltage networks.
Earth set configurations for almost any type of installation, including overhead and underground networks, and substations can be designed. They have been tested to 0.5 second ratings to meet IEC- 61230.
Product Range
Portable earth configurations vary by the was that connections are made of the phase leads and earth leads. The connection configuration of any earth set is determined by its application and the particular operating practices and experience of the user.
Sicame Australia generally manufactures earth sets to the requirements of the user, and also has a standard range of earth sets from which to choose that use aluminium cable made by Olex in Australia, and clamps made by CATU in France.
The major types of connection configuration are summarised below.
- Three Phase Shorting Circuit sets and separate earth lead
- Looped shorting and earth sets
- Three phase trifurcating plate sets
- Fixed Stick Earth Sets
- Single Phase Earth Sets
- Equipotential Bonds (EQB’s)
The CATU range of earthing clamps are available in three distinct connection types. The hexagon, shotgun and bayonet fitting. When ordering our range of CATU clamps, please refer to the table below for appropriate connection type.
| Ordering Suffix | Product number (example) | Description |
| C | MT-815-C | Hexagon Fitting |
| S | MT-815-S | Shotgun Fitting |
| E | MT-815-E | Bayonet Fitting |
10Ka for 0.5 seconds
16KA for 0.5 seconds
25KA for 0.5 seconds
‘Snap-on’ spring-loaded clamps are easy to use and very quick to place on a conductor compared to traditional screw type of clamps. The produce code for these clamps is MT-613/3.
CATU ‘Snap-on’ clamps offer the quickest and easiest way to apply phase clamps to a conductor.
To apply these clamps, the operator sets the spring-loaded jaw on each clamp, and then mounts the clamps onto an application plate on the end of a removable operating stick. The clamps can then be lifted over the conductor and ‘snapped’ onto it.
To remove the clamps, a clamp removal tool is used to pull each clamp from the conductor. Refer to product code series, CRA for the clamp remover, also know as a ‘pigtail’.