Rockwell Automation Publication 750-TG100B-EN-P - June 2019 17
Before You Begin Tests, Maintenance, or Repairs Chapter 1
Frames 7…15
The following procedures must be followed before attempting to service any part 
of the drive system.
1. Turn off and lockout all input power, including any external power sources 
(such as an Active Front End or other DC power source).
2. If present, turn off and lockout any external, single-phase 120/240V power 
source.
3. For regenerative drives and bus supplies, complete steps a…e.
a. On the input bay, turn the AC precharge disconnect switch to the 
“Off ” position.
b. Wait 15 minutes.
c. Open the enclosure door.
d. Close and lock the hasp on the circuit breaker.
e. Lock the fused disconnect switch.
WARNING: Remove power before you remove or make cable connections. 
When you remove or insert a cable connector with power applied, an electric 
arc can occur. An electric arc can cause personal injury or property damage in 
theses ways:
• An electric arc can send an erroneous signal to system field devices, which can 
cause unintended machine motion
• An electric arc can cause an explosion in a hazardous environment
Electric arcs cause excessive wear to contacts on both the module and its mating 
connector. Worn contacts can create electrical resistance.
ATTENTION: To avoid an electric shock hazard when servicing the drive, a 
means for lockout/tagout of the external, single-phase 120/240V power source 
and, if present, external 120V uninterruptible power supply source, must be 
provided.