Model 27 True RMS Current Monitor has a display that shows the current with an accuracy of +/- 0.5%. The display is updated every second and re-initialized every 30 seconds. Model 27 has a rotary encoder with switch on the unit. By pressing the encoder switch for more than 5 seconds, the unit will enter the setup mode. This unit has a user selectable relay option for High-Low or DPDT. It can also be user-selected to energize on fault or de-energize on fault. The user can select automatic or manual restart on the Model 27. The SG version of the Model 27 has silver with gold flash contacts for low current applications. Model 27 True RMS Current Monitor can be either calibrated using a True RMS Multimeter or can be restored to factory defaults in the field.