[dunnitagain]

Hello All. We have a 4 year old SL20 that on start up gives a Low DC Bus Voltage Error. Haas said it could be the Vector Drive? It will clear and work all day. But errors first thing on start up. Anyone else have this problem? I would think a vector drive would last longer than 4 years and 1000 HRS. Thanks

[Bryan33]

The Vector drive sends 1 volt to every 100 volts of your dc buss to your mocon pcb. It plugs in on P17 of your mocon. What is your dc buss right now. It should be 225v to 245v dc

[double a-ron]

Yup, I got that problem. Did you read my post? Weird.

[Andy S]

Had thet same problem with our mill. Had a local service guy replace some little black micro chip on the vector drive to cure our problem. our vc had the correct dc voltage but it was not reading correctly at the control panel, giving a low voltage error. That cured our problem for about a year before we finally had to replace the drive.

[dunnitagain]

Well I checked the DC voltage at the drive. At turn on the voltage on the taps at the drive instantly goes to 345 VDC. The taps at the drives are the same. I checked the signal at P17 on the Mocon Board ,it slowly builds from 2.300 VDC to 2.55 VDC as you watch it. Also the fan on the VD doesnt run at fire up, is it a temp controled fan? One more question is it better to err on the lows side of the voltage taps on the transformer? my voltage measures 214 at the breaker. But drops to 207 with the spindle running. The voltage taps change at 210. Thanks for all your help. Dwayne

[haastec]

If it has fans, they should be running. Do the fans come on at all?

If they do not turn on, this is the root cause to your problems; overheating of the components.

While your are in there, check all the other fans to make sure they are running.

[dunnitagain]

The fan on the VD comes on after some use. The fan on the amplifer cards runs as soon as you turn on the power. We only get low bus volt error at start up after the machine is cold.

[eclipseseal]

Hi Andy, do you have any idea which chip your repair guy replaced?
I know this has been a while, we are having start up issues, and if we let the machine set in the alarm state for 5 minutes and do a restart, it comes up which tells me, something is warming up. If we shut down during the day and turn it back on, it comes right back up with no alarms (everything nice and warm temp wise)
Thanks in advance,
cliff

[mactec54]

Well I checked the DC voltage at the drive. At turn on the voltage on the taps at the drive instantly goes to 345 VDC. The taps at the drives are the same. I checked the signal at P17 on the Mocon Board ,it slowly builds from 2.300 VDC to 2.55 VDC as you watch it. Also the fan on the VD doesnt run at fire up, is it a temp controled fan? One more question is it better to err on the lows side of the voltage taps on the transformer? my voltage measures 214 at the breaker. But drops to 207 with the spindle running. The voltage taps change at 210. Thanks for all your help. Dwayne

Your Dc Bus voltage is right where it should be 336v to 345v if you are using 240v Supply, do you have 3Ph power or are you using a RPC

[airjet]

Hello All. We have a 4 year old SL20 that on start up gives a Low DC Bus Voltage Error. Haas said it could be the Vector Drive? It will clear and work all day. But errors first thing on start up. Anyone else have this problem? I would think a vector drive would last longer than 4 years and 1000 HRS. Thanks

325-340 DC bus is what you want to see on Haas machines.
When you start the machine in the morning it’s probably not reading this voltage (checked in diagnostic page ... page down ) you will see DC BUS ...
Most coming problem with vector drives. You just have to wait 10 min before the voltage will gets to 320 and reset it.

[mactec54]

325-340 DC bus is what you want to see on Haas machines.
When you start the machine in the morning it’s probably not reading this voltage (checked in diagnostic page ... page down ) you will see DC BUS ...
Most coming problem with vector drives. You just have to wait 10 min before the voltage will gets to 320 and reset it.

If you have to do this then you have a capacitor problem

[airjet]

If you have to do this then you have a capacitor problem

When you getting right voltage from the vector drive - it’s not a capacitor

[airjet]

Well I checked the DC voltage at the drive. At turn on the voltage on the taps at the drive instantly goes to 345 VDC. The taps at the drives are the same. I checked the signal at P17 on the Mocon Board ,it slowly builds from 2.300 VDC to 2.55 VDC as you watch it. Also the fan on the VD doesnt run at fire up, is it a temp controled fan? One more question is it better to err on the lows side of the voltage taps on the transformer? my voltage measures 214 at the breaker. But drops to 207 with the spindle running. The voltage taps change at 210. Thanks for all your help. Dwayne

it slowly builds from 2.300 VDC to 2.55 VDC as you watch it.
That is your problem - sensor not reading the voltage from drive