Mounting Bracket Arrangements for the OSM Recloser System

With the launch of the cantilever bracket for NOJA Power’s OSM Recloser system, this brief article provides an overview of bracket options for installations.

There are three primary installation methods for NOJA Power’s OSM Recloser as shown in figure 1.

The first option is the conventional design, as it offers the greatest flexibility. A separate bracket is used for the OSM (the OMB-18 Bracket), and the Auxiliary Voltage Transformer (VTMB-10). The smaller bracket option allows for most compact shipping design, and is the most cost effective method from a raw materials standpoint.

The key advantage of the latter two designs is to allow for live line approach distance to the clean side of the pole. Placing all the high voltage equipment on one side of the pole gives greater clearance for live line work. Let’s consider the two options for a one-sided installation.

Option 2, the Combined bracket, uses the same bracket for both the Aux Voltage Transformer and the OSM Recloser. They are installed on the downstream side of the pole. This is common where a pre-dressed Recloser solution is selected, minimising site works but increasing the physical dimensions of the shipped equipment.

Lastly, the Cantilever bracket allows the NOJA Power OSM Recloser to directly replace legacy switchgear designs which had the VT and Recloser installed on the source side of the pole. This option is the most costly design from an equipment perspective, but it minimises re-engineering costs. Operators familiar with older generations of equipment can use an OSM Recloser as a direct replacement for prior designs, maximising legacy equipment compatibility.

“Having a dedicated VT on the same pole allows for everything to be connected to the same MV earthing system and will provide the best impulse integrity for the installation,” says NOJA Power Group Managing Director Neil O'Sullivan.

All these bracket options are in common use throughout NOJA Power’s 100,000 OSM Recloser installations worldwide. NOJA Power’s technical staff are available to discuss your application requirements, to help you maximise your reliability benefits from your investment.

For more information, visit www.nojapower.com.au or contact your local NOJA Power Distributor.