VFD's and Cold

[Amber Gold]

Got to the woods this morning and the pump was off and the VFD was acting weird. On light on, and display looking weird. This is the second night this week where we've had frigid temps and high winds, and I woke up to the same situation. The VFD is inside the pump shed, but it's next to the door which doesn't seal tight. Do VFD's not like the cold? When it happened the other day, I went back to the woods a couple hours later, the VFD was back on, so I fired the pump, and everything was good. It's not going to run today, so I just left it.

I've typically run the vac. pump all season w/out shutting it down for cold snaps and haven't had a problem in the past. It's a Hitachi VFD that's say 6 y.o. if that matters.

Thanks for the help.

[DrTimPerkins]

The VFD is inside the pump shed, but it's next to the door which doesn't seal tight. Do VFD's not like the cold?

Cold typically doesn't bother them much, but water sure does. With the wind/rain we had, are you sure it didn't get wet? Electronics do NOT like wet.

The other issue is when it is cold, VFDs should be turned on and the electronics allowed to warm up for a while before the pump is turned on.

[GeneralStark]

Josh - I had some issues with an Hitachi drive last season so I called the vendor (driveswarehouse) and talked me thru some troubleshooting. It turned out the drive was bad and they replaced it. During the whole process the question of conditions in the room where the drive is stored did come up. They did not seem to think temp. was an issue but certainly moisture is bad news. Often electronics actually perform better in cold temps., but drives do not like hot conditions.

I say call the vendor and see what they think. The drives will generally store a code if there is some fault. It would also be a good idea to check that you are getting clean power to the VFD breaker. Even a loose connection somewhere may cause issues.

[Amber Gold]

I was thinking cold should be OK too.
Dry, yes although when the cooling line freezes, the storage tank heats up and creates moisture in the air, but the top is cracked open and it vents outside. I haven't seen any condensation on the VFD itself. I do have a plastic shield over the top of it to make sure no rain water drips. The VFD is really deep, so it does not fit into a normal enclosure like I'd like to have it.
Connections, haven't checked those, so will do that. I got it from driveswarehouse. This is actually the second one. The first one fried mid-season in its second year of use (not warrantied of course). This one's going on 6-7 years. When it blanked out earlier this week, the power light was on, but nothing on the display. When I came back two hours later, the display was back on with no error code. Started the pump up and it worked. This morning, the power light was on, the display blinking, and the VFD was making a light pulsing type noise that corresponded with the VFD pulsing. Going back tonight to check on it.
I'll call driveswarehouse. I'm borrowing a backup VFD if I need it.
Thanks for the help.

[Amber Gold]

Checked the VFD this morning and still on the fritz. Checked the connections and still good. Checked incoming voltage, 120V on each leg. Called driveswarehouse, and they said it's fried, and even it was say the logic board, it wouldn't be cost effective to replace it.

Backup VFD is here. Will hook it up tomorrow morning and see if we get any sap.

The VFD is about 6 y.o. Is this the typical lifespane of a VFD? Aside from keeping moisture away from it, should I be keeping it in the house during the off-season? At 6yrs, it cost me about $40/yr to own it, so wondering if it makes since sticking with 3 phase vs. going to a single phase motor and paying for the higher electric cost.

[BAP]

You should check your voltage and amperage under load to make sure that there isn't a drop when running. Low voltage when running can burn up electronics and motors. You may find that you have 120v on each leg when not on, but much less when the pump is running. I don't know about the life span of that brand, but when I used to farm and milk cows, we had one on our vacuum pump that ran 14+ hours a day/ 365 days a year and lasted about 10 years until a lightning strike to it out.