Retrofit of Crosshead Motor and Controls on Southwark-Emery 600k Tester
2/25/2009
Figure 1: New crosshead
motor control panel, including
continuously variable speed
controls.
Figure 2: New variable speed
AC motor, before installation.
Figure 3: Relay box of old
crosshead motor before
decommissioning.
Figure 4: New variable speed
AC motor controller.
With the replacement of the old AC crosshead motor, Stage 2 of the full rehabilitation of the Southwark-Emery universal testing machine is complete. Dreadfully slow crosshead jog speeds are now a thing of the past. The old single-speed motor has been replaced by a brand new computer-controlled AC motor, which has quadrupled overall crosshead speeds. The new system provides programmable acceleration and deceleration rates as well as continuously variable speed control. For added safety, limit switches have been installed to prevent the movable crosshead from impacting the fixed crosshead. This retrofit will allow the lab to perform materials testing at a significantly swifter rate, especially if testing is performed on specimens of different length, requiring significant jogging of the crosshead.