VFD temperature sensitive?

[gmcooper]

I am planning to install a new vacuum pump with a VFD this year. I noticed that some VFD have a lower temp limit as well as an upper limit. Do they need to be in a heated building? Some VFD's when I read specs on were good to -10 C and at least one was only rated to 0 C. My current pump house is not heated. Anyone have any issues with cold temps effecting a VFD?

[S.S.S]

have never had a issue and mine sits right outside.

[GeneralStark]

The bigger issue with VFDs is typically heat, but just follow the manufacturer's recommendations and you should be fine.

[DrTimPerkins]

There can be issues with VFDs that are very cold when they are first started. The correct procedure in that case (and a good idea for all times) is to turn on power to the VFD first, allow it to warm up for 5 min, then turn on the pump. Otherwise you're asking the device to go from very cold to pump start-up (when the amperage draw is high) immediately. This can fry the electronics. Typically though we aren't starting VFDs when it is terribly cold, so we've not seen any problem with them.

[sapman]

The cold can also affect your vacuum pump, depending on which kind you are using, so I've heard. I've got a Busch pump with electric releaser, so a heated space was necessary. But I heard of another producer with a Busch that had lots of trouble because he had no heat.

[gmcooper]

Thanks everyone. I met with my electrician today and he did not know of any issues with cold temps effecting VFD. He did make same recommendation as Dr Perkins about start up vfd and warming up before starting motor.

[Tweegs]

Yes, any electronic device that has anything to do with “frequency” should be given a moment for the components to warm up and stabilize before being put into service.
Weird stuff can happen if you don’t, greatly increased inrush current being one possibility.

There’s a real opportunity for a dissertation here, but I don’t want to write it and you don’t want to read it.

The short of it is:
Greatly increased inrush current has a tendency to let the magic smoke out of electronic components.
Magic smoke is the key ingredient to all electronics, and once set free, the components quit working...every single time.

I’ve been on a rant lately and I’m still not ready to get off that horse, so…
Stay away from cheap Chinese knock-offs purchased through e-bay.
I could detail why, but again, you don’t have that kind of time.
Suffice to say, they’re cheap for a reason and a CE stamp on these products means absolutely nothing.

Now another thought, and just a thought:
The oil in a vacuum pump is going to get a little thick in cold temps, I'd assume.
This is going to provide resistance to start-up, which in turn is going to increase the inrush current.
(Maybe this is why it’s recommended to keep some pumps warm?)
Would it be possible to put a small block heater, small battery blanket or ceramic space heater on, near or around the oil reservoir? As opposed to heating a room, that is.

[DrTimPerkins]

Magic smoke is the key ingredient to all electronics, and once set free, the components quit working...every single time.

Perfect explanation.

I've had at least a couple of very memorable occasions when the "magic" managed to escape from various components I was working on. It can be quite spectacular, but as you say....always results in inoperable equipment.

[Tweegs]

Blowing up capacitors is a personal favorite.
I once set off a bank of 14 electrolytic’s in rapid succession because I wired them wrong.
Had to endure a couple of years’ worth of jokes for that little stunt.

Ever see a chip do that Fourth of July glow worm thing? I have.
(Soldered it in 180 out)

Why just yesterday I sent a sweet little microcontroller to the trash.
You’d figure that after over three decades of fooling around with this stuff I’d know not to short 5V directly to ground.
Nope, apparently not.
:lol:

[Shiftman]

We once had a VFD produce magic smoke... And even magic fire. We were lucky our pump house didnt burn down. We think it was a lose termination.