Enatel DC System Manual
Page 15 of 31
7.0
DC
E
ARTHING
The 1U micro system is available with two DC Earthing options. The first is fixed by hardware as
a positive earth system where the positive DC output is tied to AC earth. This cannot be
changed in the field.
With the second option, AC earth can be tied to either the positive or negative output by simply
inverting the -/+ earth PCB. The monitor signals are modified by rotating the second PCB as
shown in figures 9 & 10. The two PCB’s mechanically interlock, preventing incompatible
connections to be made.
+ve Earth
-ve Earth
+ve earth
-ve earth
Fig 9 & 10, +ve earth and -ve earth options
For systems that require no connection to earth, the PCB can be cut as indicated in figure 11 to
isolate DC output from AC earth. This modification should be made with both -/+ earth PCB’s in
the +ve earth position (or with the fixed positive earth system)
Fig 11, isolated earth option
