Rolla regularly supply corner units as part of a Motor Control Centre or Switchboard. They are aften used to limit the length of the board and make maximum use of the available space.
The main busbars, earth bar and all control wiring must be directed around the corner (usually 90 degrees). As standard our main earth bar is located in the top front chamber for easy access, along with any control wiring.
Sometimes two corners are used to allow an MCC to fit into a very confined space. Although most corners are "inside", with the front of the MCC facing inwards, we also supply outside corners where appropriate.
Often only the main bars are required around a corner so can also supply a top-box only version as shown above.
In some cases the space within the corner can be utilised for equipment such as power factor correction etc.
Corner units contain an offset to one side to ensure adjacent doors can be opened without clashing.
Rolla corner units have been extensively type tested at 50KA and 80KA.
Test at 50KA, top covers removed for inspection after the test.
Test at 80KA, including the earth bar around the corner.
After the short circuit test, the continuity is checked and an impulse test carried out.