
MANUAL MOTOR STARTER GUIDE
APRIL 19
16/80
2.1.6 Phase loss sensitivity
Phase loss sensitivity is a characteristic of an inverse time-delay and thermal over-current releases. A strong imbal-
ance between phases can damage motors and other loads. Manual motor starters are designed to detect these
conditions and trip to prevent load-side circuit and motor damage.
2.1.7 Single-phase and direct current (DC) loads
In order for manual motor starters to protect single-phase loads or direct current (DC) loads, all three main poles
must be connected in series (see figures below).
Figure 4: Connection diagram for single-phase and direct current.