DYN4 Overcurrent, but only on initial startup

[prodiemaker]

yes, logic come on when I power up cabinet, e stop does not engage until oak board runs thru startup sequence. DMM thinks initial amp requirement is too large to put contactors in and have drives come on one at a time. But I have a 30 amp breaker on system and it does not trip. I have also unplugged motor power from other two drives only powering up 1 drive. still get alarm. but I can power up motor power on all three thru a standard surge protector strip on 110v and system will not alarm out for over current/ Voltage. ?

[mactec54]

yes, logic come on when I power up cabinet, e stop does not engage until oak board runs thru startup sequence. DMM thinks initial amp requirement is too large to put contactors in and have drives come on one at a time. But I have a 30 amp breaker on system and it does not trip. I have also unplugged motor power from other two drives only powering up 1 drive. still get alarm. but I can power up motor power on all three thru a standard surge protector strip on 110v and system will not alarm out for over current/ Voltage. ?

The control should be the first thing to power up then the Drives with a power on button, it could be your Estop circuit that is causing the problem

[Jim Dawson]

Here is how I have mine wired

System: Four DYN4 1.8kW drives, plus a 7.5kW spindle servo drive
Main machine breaker/main power switch: 100 Amp
Each DYN4 drive has its own 30 Amp breaker and 30 Amp contactor

Wired per the DMM manual with logic (L1, L2) powered by the contactors.

Controller is on a separate 120V circuit, so it is always on.

Main power switch powers up the 120VAC control transformer and 24VDC control power supply, also brings up a couple of cabinet fans

Control Power button turns on the rest of the cabinet fans, hydraulic pump, and the spindle servo drive

After resetting the controller, pull out the E stop button and press the Enable button.

If the controller allows (no errors) (controller E stop permissive), the following happens:

The DYN4 drives are powered on one at a time with a 1 second delay between, the drive enable inputs are still low at this time (disabled) by the controller. Again DYN4 logic is powered by the contactors.

Once the drives are stable and no errors (about 500ms), then the software enables the drives.

I tried powering the DYN4 logic on control power enable, but I was getting servo trips on startup. Wiring and controlling as above eliminated that problem.