light intensities or comparing current measurements at various load locations will isolate the
(1) Figure 24 illustrates a typical airfield circuit using an S1 cutout (S1-A) and an
S1 arranged as an "Intentional Ground Switch" (S1-B). The intentional ground is not being
applied to the load. To do so we would have to remove the handle on the intentional ground
switch. Notice in the figure that the ground current indicating light is off.
45 W EDGE LIGHT
45 W ISOLATION
S1-A: TYPICAL INSTALLATION ON LOAD CIRCUIT
S1-B: INTENTIONAL GROUND SWITCH WITH GROUND CURRENT INDICATING LIGHT
SCHEMATIC ILLUSTRATES S1 HANDLES INSTALLED.
CAUTION: OPERATE S1 HANDLES WITH LOAD DE-ENGERGIZED
Regulator Connected to Typical S1 Cutout and Intentional Ground Switch With Ground Current
(2) Figure 25 illustrates what happens to the lights when the handle of the
intentional ground switch is removed. The ground point on the load is providing an alternate
path for the circuit current, causing the lights between the intentional ground and the ground fault