294 Rockwell Automation Publication 750-TG100B-EN-P - June 2019
Chapter 11 Start Up After Repairs
Frames 7…15
1. For regenerative drives and bus supplies, measure the AC input and DC 
bus voltage at the following testpoint sockets in the power bay to verify 
that there is no voltage present:
• Use the circuit breaker output (CB1 SEC) testpoints R/L1, S/L2, and 
T/L3 to measure L to L and L to chassis GND.
• Use the fused disconnect output (FD1 SEC) testpoints R, S, and T to 
measure L to L and L to chassis GND.
• Use the DC bus testpoints +DC and –DC to measure +DC to –DC, 
+DC to chassis GND, and –DC to chassis GND. 
ATTENTION: To avoid an electric shock hazard, verify that there is no AC input 
and DC bus voltage by taking these measurements:
• Verify that there is no AC input voltage present at the circuit breaker by using 
the R/L1, S/L2, and T/L3 testpoint sockets in the input bay and by measuring L 
to L and L to GND.
• Verify that there is no AC input voltage present at the fused disconnect by using 
the R, S, and T testpoint sockets in the input bay and by measuring L to L and L 
to GND.
• Verify that there is no DC bus voltage present by using the +DC to –DC test 
points in the input bay and by measuring +DC to –DC, +DC to GND, and –DC to 
GND.