- Excellent heat dissipation.
- Resistant elements attached mechanically by solid bands that are at relatively low temperature compared to the active part.
- An increased service life for the resistant elements as well as holding and insulating parts. Moreover, the mechanical studiness of assemblies is preserved.
The Gridex U system is made from collections of expanded metal grids (RU) edged :
- on the two short sides, by adhering solid band designed for mechanical attachment and for the electrical connections,
- on the two long sides by U section stainless-steel stiffeners. A flexible insulating tape (mica paper) housed inside the stiffener, whilst considerably protruding, provides insulation between the latter and the edge of the grid.
Grids are stacked together on two steel tie rods threaded at the ends. Insulation between the grids and rods is obtained by shouldered ceramic rings. The assembly is locked by nuts and “contact washers”.
The connection between grids designed to ensure continuity of the electrical circuit are obtained by a stainless steel jumper hot spot welded to consecutive grids. Welded jumpers confer excellent mechanical rigidity of the whole unit. They are duplicated in case of high current.
Gridex U Grids design allow us to obtain different types of grids with standard dimensions (180 x 360) with resistance values varying from 0.0114 à 12.7 ohms according to the grid thickness (from 0.4 to 3 mm) or resistance material alloy of mesh type. Each grid can withstand 600V or 1.2 kV BIL
- Neutral Earthing Resistor
- Harmonics filter for SVC or HVDC Sub-stations
- Load banks
- Rheostatic control
The different type of used alloys are :
- Nickel chromium stainless steel (18% Cr, 10% Ni AISI 304, 20% Cr, 32% Ni 32/20)
- Aluminium chromium steel Cv AP