VFD and cold weather.

[ptonsparky]

We installed a VFD for an irrigation well a couple years ago. Pump Panel type enclosure designed for the use and supplied with the VFD. They tried to run it today to water cattle. Temperature in the low 30s to upper 20s this afternoon. Yaskawa Drive. Is there a minimum temperature range to operate them in with this type of enclosure I see for open and type 1 enclosures its -10C to +40 C. Should it have a heater, might be the better question? It will have to run at least twice a day regardless of the temp.

The LCD display for that thing is just lovely to look at with the bright afternoon sun reflecting off snow cover. I'll have to hook up the laptop tomorrow, to find the fault code, and that's marginally better. Add the temp is supposed to drop and winds come up as the morning progresses. Fun.

 

[drcampbell]

... for open and type 1 enclosures its -10°C to +40°C. ...

The manufacturer's specification should answer your question. An LCD display might be dim and/or slow to change, but that won't affect the drive's basic operation.
I would be more suspicious of ice in the pipes or pump than a drive problem.

 

[ptonsparky]

The manufacturer's specification should answer your question. An LCD display might be dim and/or slow to change, but that won't affect the drive's basic operation.
I would be more suspicious of ice in the pipes or pump than a drive problem.

No ice, pump turns, drive has a fault code but I can’t see the display well enough to read the code. The motor starts to ramp slowly and the load reactor sounds wierd before we shut it down. Yes I’ve heard arcs and sparks, not that.

 

[Jraef]

If the capacitors freeze and are energized, they can explode. Sometimes it’s a big bang explosion, sometimes they just pop and spew their goo all over inside. So yes, you definitely need panel heaters and if there is a risk of frequent power outages (our power disconnection) where there will then be no heat, you need further precautions. There is also the problem of running the drive in the cold, then turning it off and the warm drive collects condensation all over the innards, shorting things out inside. So the goal is to keep the inside of the enclosure above the dew point st all times.

 

[Besoeker]

If the capacitors freeze and are energized, they can explode. Sometimes it’s a big bang explosion, sometimes they just pop and spew their goo all over inside. So yes, you definitely need panel heaters and if there is a risk of frequent power outages (our power disconnection) where there will then be no heat, you need further precautions. There is also the problem of running the drive in the cold, then turning it off and the warm drive collects condensation all over the innards, shorting things out inside. So the goal is to keep the inside of the enclosure above the dew point st all times.

Agree. IIRC, 0-40C was the usual temp range permitted. For us, the VFD was usually in a panel along the associated controls including an anti condensation heater and thermostat. And yes, the electrolytic bucket caps were a limitation.

 

[junkhound]

Have tested aluminum electrolytic caps down to -55C and never have seen one damaged.
What happens at about -30C is that the ESR goes way high and it is like the cap has a kilohm series resistance.
An aluminum electrolytic at -30C in a DC link in VFD the ripple may increase to levels where the VFD Fets or IGBTs would get overvoltage transients and blow, especially if the front end is a PFC circuit.
The OP description is that the VFD does start to operate but shuts down - probable that there are overvoltage/overcurrent protective controls that shut down the PFC or H bridge drivers when the DC link voltage goes too high.

HAVE seen aluminum electrolytic caps blow up when HOT, but never at sub freezing temperatures.

In the OP, were the 20 and 30 degree references supposed to read MINUS 20 and 30 C? Us south of the border folks may have interpreted that as 20F and 30F which makes no sense as being a capacitor problem.

 

[ptonsparky]

Have tested aluminum electrolytic caps down to -55C and never have seen one damaged.
What happens at about -30C is that the ESR goes way high and it is like the cap has a kilohm series resistance.
An aluminum electrolytic at -30C in a DC link in VFD the ripple may increase to levels where the VFD Fets or IGBTs would get overvoltage transients and blow, especially if the front end is a PFC circuit.
The OP description is that the VFD does start to operate but shuts down - probable that there are overvoltage/overcurrent protective controls that shut down the PFC or H bridge drivers when the DC link voltage goes too high.

HAVE seen aluminum electrolytic caps blow up when HOT, but never at sub freezing temperatures.

In the OP, were the 20 and 30 degree references supposed to read MINUS 20 and 30 C? Us south of the border folks may have interpreted that as 20F and 30F which makes no sense as being a capacitor problem.

Yesterdays temps were degree F.

 

[Besoeker]

Have tested aluminum electrolytic caps down to -55C and never have seen one damaged.

Was that under operating conditions like say, in a VFD?

 

[Besoeker]

Yesterdays temps were degree F.

Aren't your terminations rated in deg C?

 

[junkhound]

Was that under operating conditions like say, in a VFD?

Yes, a switching power supply and motor drive for a military aircraft.
A supplier wanted to try using common cylindrical aluminum electrolytics vs. film or ceramic caps for dc output and dc link holdup, tested to show supplier they would not work.

Note: have tested the CDE flat pack electrolytics and those specific caps DO work at -55C. A different type part ( and 10X the $$ also) from the common cylindrical can aluminum electrolytic caps.

edit PS: IF OP temps were +20 deg F as updated, then cap temperature not a factor IMP.

 

[Besoeker]

Yes, a switching power supply and motor drive for a military aircraft.

If the ESR goes way high as you put it, wouldn't there be self heating which would take it above the operating ambient?

 

[drcampbell]

Yesterdays temps were degree F.

Aren't your terminations [and the VFD] rated in deg C?

Yes, we Americans use two (or more) different measurement systems in order to achieve the maximum possible confusion.

 

[ptonsparky]

Aren't your terminations rated in deg C?

Yes the terminations are rated in C. My yesterdays outdoor ambient temperatures I stated are in F.

 

[Besoeker]

Yes, we Americans use two (or more) different measurement systems in order to achieve the maximum possible confusion.

I like that........
My dear wife, as you may know, is from Georgia. US Georgia that is. I do the conversions for her so right now it is 8.3°C or 47°F. That's an easy enough conversion.
But it's different matter when it comes to baking cakes. And my wife does a lot of that. US measures are often by volume - a cup of sugar for example. UK recipies are usually by weight. Maybe 100g of butter.

Sorry mods.
Pretty much all of our VFDs were indoors and had forced air cooling.

 

[Jraef]

Yes, a switching power supply and motor drive for a military aircraft.
A supplier wanted to try using common cylindrical aluminum electrolytics vs. film or ceramic caps for dc output and dc link holdup, tested to show supplier they would not work.

Note: have tested the CDE flat pack electrolytics and those specific caps DO work at -55C. A different type part ( and 10X the $$ also) from the common cylindrical can aluminum electrolytic caps.

edit PS: IF OP temps were +20 deg F as updated, then cap temperature not a factor IMP.

Well, maybe you were testing MIL spec components or something, but I had an ABB drive explode on the side of Mount Hood in Oregon when the rock crusher operator fired up the generator after being off all night (meaning no panel heater) and the simple act of closing the breaker to feed power to the drive was the event trigger. Those caps exploded like a bomb going off, it blew the door off of the drive enclosure and sent it sailing down the mountainside like a frisbee. The temperature was about 20F when that happened, although we don’t know how cold it got at night up on the slope (we were down the mountain in a cozy motel).

 

[ptonsparky]

Its tripping on Drive Overload. OL2. Drive is sized correctly.

Disconnecting all load from the motor still causes trip. We increased the torque compensation and time to no avail. Manuals says to decrease torque compensation. Will try that after thawing feet. Temperature was in the upper 20s this morning but is dropping steadily. Nice 30mph breeze makes this more fun.

Phases are there. Not too high. Might disconnect motor entirely to see what happens then.

Motor was stuck tight this morning when I first got there. We freed it up and the owners tell me they checked for that yesterday. Upper bearing oil is thick.

 

[Jraef]

I don't know if yours has it, but some VFDs offer an option to use the VFD as a trickle heater for the motor, wherein it puts a small about of DC through one winding (i.e. DC injection braking) just to keep it warm. Worth checking into.

PS:
I have a manual for an A1000 Yaskawa and it doesn't appear to have that feature. But it DOES allow you to enable a "pre-start" DC injection braking of up to 75% current for up to 10 seconds. 10 seconds isn't likely long enough to make enough heat, but if you do it multiple times in a row it might be.

 

[ptonsparky]

It was the motor, even though it passed the smell test. Checking 1-2, 1-3, and 2-3, one set showed 0 ohms, the others .04-.05. It didn’t meg well either.

Farmer drained old and put new new oil in upper bearing reservoir. found ice in old oil. To late.

 

[ptonsparky]

The manufacturer's specification should answer your question. An LCD display might be dim and/or slow to change, but that won't affect the drive's basic operation.
I would be more suspicious of ice in the pipes or pump than a drive problem.

You were close.

 

[ptonsparky]

By my calcs via a mfg worksheet and a vendors suggestion it looks like a 400 watt heater will be sufficient. That will load up the 500 watt control transformer pretty well, but I can interlock via controls to shut the heater off whenever the control is in hand or even if the drive is in run.

How much added heat will the transformer give me while it is powering the heater? I'm not concerned about too much heat, but some added heat won't bother if and when we ever see -20F again.