Chiller starter vfd cabinet

[Sparkie010]

New chiller with starter cabinet was wired with the line side landed on the load side and load side was landed on the line side. The start up guy said that a board blew up and is now trying to charge 40,000 for fixing it. 480 volts on the load side would still be 480 volts on the line side. Would hooking up the load side of starter cabinet with line voltage cause damage to the components inside?

 

[paulengr]

Sounds like total BS. No control power as you are on the wrong side of the drive/starter and no way to close things in. Call a competent motor shop in your area. I’m betting they got a wye delta and messed up the motor wiring and didn’t do SCCR with cheap 5 kA contactors or drive without the correct OCPD so they smoked the motor and welded contactors or wiped out the drive. So now they expect you to pay to fix it plus pay for the third party inspection to prevent this. The wiring is utter total BS.

Plus if you paid for a certified drives/chiller startup tech you start with the motor uncoupled and unwired and do a basic continuity and insulation resistance test as a safety measure before you energize anything. That is in the startup tech paperwork. The drive/control companies require this with documentation as it is cheap liability protection.

Plus 40k are you kidding me? Way out of line.

If you are in the South or mid Atlantic PM me. That company should be ashamed of themselves.

While you are sitting down to eat your turkey next week or getting your Pfizer vaccine chances are I’m THAT guy. So I’m not buying anything you are being told.

 

[ptonsparky]

Did someone put 480 to the load side of the VFD? That would be a big OOPS!

 

[paulengr]

Did someone put 480 to the load side of the VFD? That would be a big OOPS!

How? It is well within the voltage rating of the IGBTs. And they don’t have any gate voltage so it can’t operate. Please explain your comment as you are making my point.

One of the occasional issues I see with VFD retrofits is 90% of drives have L1, L2, L3 on left and T1, T2, T3 on the right with DC bus and various brake options in the middle. A small number do something different, mostly opposite order. So it happens occasionally when you can’t readily identify the wiring but I haven’t seen it do anything except drive won’t power up. So...huh?

 

[don_resqcapt19]

From a product engineer at Yaskawa America, Drives and Motion Division.

Switch the VFD input and output power leads — Even though nearly every major VFD manufacturer defaults to input power terminals on the left and output power terminals on the right, it’s still a regular occurrence that said manufacturers’ repair departments receive damaged drives where the connections are reversed. Some of today’s VFDs can withstand being powered up with the power leads reversed, but the failure rate increases if the RUN button is pressed.

 

[Jraef]

Your title says VFD, then you talk about a starter. A Starter, no, it would not damage anything. A VFD, absolutely possible. I've seen it happen, twice. Total destruction of the VFD.

$40k to "rebuild" it in the field might be excessive, but we don't know the size of the VFD. 400-600HP chillers are not unheard of. But if that is for a field re-build, forget it. Just replace the entire drive. I've been down that route, you fix one damaged part, then the next weak part blows, so you fix that, then the next one blows, right on down the line until you have replaced the entire drive, one component at a time. It's just like a car; the sum of the replacement parts is WAY more than the entire unit.

 

[winnie]

How? It is well within the voltage rating of the IGBTs. And they don’t have any gate voltage so it can’t operate. Please explain your comment as you are making my point.

If you connect 480V to the output of a drive, I'd expect the diodes in the output bridge to conduct and try to charge the DC bus. Well within the voltage handling capability of the devices, but without any sort of precharge current limiting.

Depending on the size of the cap bank and the impedance of the AC supply, fireworks would certainly be possible.

Jon