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Rockwell Automation Publication 750-UM006C-EN-P - March 2022
Chapter 6
Troubleshooting
2. Turn off the Main 400/480V AC input circuit breaker.
3. With the main breaker open, determine if the cover-mounted HIM is
energized.
• If yes, then the 24V DC control power (CP) is present. Control
Power must be present to monitor the Input I/O status.
• If no, then energize the 24V DC control power. See
for more details.
4. Turn the Main circuit breaker on before proceeding to
. See
and follow the instructions to energize the system.
5. Check
00:11 [DC Bus volts]
:
• If it is between 515…670V AC then the main incoming (400/480V
AC) is present through the L123 receptacle and the main input
circuit breaker is closed.
• If it is not between 515…670V AC, then either the main input rotary
breaker is open or there is no power present on the L123 receptacle.
• If there is no power present at the L123 receptacle, go to the customer
Power Distribution Panel (PDP) and verify the power source to the
M35 trunk line is energized (400/480V AC).
6. If 24V DC (CP) control power circuit breaker from
is energized
and the main input power is present, then the only breaker that can be
open is the brake circuit breaker. Reset the breaker and recheck
07:01
[Dig In Sts]
bit 1 to confirm that all three breakers are now closed.
Notes:
• You must use a tool to open the auxiliary circuit breaker door on the
front cover to inspect the mechanical brake and 24V DC control
circuit breakers.
• There are two types of brake circuit breakers:
(1) 24V DC breaker for brake Option B2 or B3 (CPBR).
(2) 400/480V AC breaker for brake option SB (L123).
•
07:01 [Dig In Sts]
should always be assigned and used as one of the
Datalinks (to the PAC Network) for remote monitoring of the brake
contactor status (Bit 0), CB status (Bit 1), and the P0 & P1 status
(Bits 2, 3, 4, 5).
ATTENTION:
Do not cycle 400/480V AC power more frequently than one
cycle every 1 minute - failure to comply will result in serious equipment
damage.
