VFD w/ Integral Disconnect

Looking for recommendation for VFD's with Integral Line Side Disconnect and Fuse. 15HP Booster Pump application.

I see Danfoss makes their Aqua Drive series, and Siemens has their BT300 Series. Neither of which I have used in the past. (Anyone have any experience?)

What others are out their?

And before anyone asks, I don't have room for a drive in a box with separate components. It takes up more space than an all-in-one package, maintaining clearances.

(Edited for clarification)

Is this a line side disconnect / fuse, or load side of the VFD? Schneider do the ATV650 series process drives with a built in load side isolator switch.

I haven't seen anything with line side though, but maybe that's just because we wouldn't do it that way this side of the ditch. Fuses / MCCB would be in the switchboard.

The Danfoss VLT aqua drives are a very capable product. Physically much better built than the Schneider equivalent, and smaller as well.

I do prefer Schneider drives for modbus interface though.

Both have good built in pump function and monitoring features.

Saffa said:

Is this a line side disconnect / fuse, or load side of the VFD?

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The Danfoss drive has disco and fuses on line side. Here is a reference: https://files.danfoss.com/download/Drives/MI92D402.pdf

at my last plant, we used hundreds of AB vfd's with a non fused disconnect and an aux contact that went to the plc to tell us when it was in the off position. it was on the load side. fuses were also on the line side. sime even had a fused disconnect on the line side.
james

Ah Yup, even says for North American market. Interesting! Is this a electrical regulations thing over there? I'm just curious why you'd need to fuse inside the drive instead of just putting them back in the switchboard. Or would these be fast acting semiconductor fuses for protecting the drive, then you just have a suitably rated circuit breaker for protecting the cable out to the drive?

It looks like a Standard Danfoss VLT Aqua in all other regards, so i think you'll be all good going with this drive for any standard pump application. They have a good internal PID with sleep function for continuous pressure boosting applications where you just wire the pressure sensor into the drive analog input, and can do the SP from the HMI.

ABB ACH series can be purchased with disonnect and fuses.

Lenze SMVector come as a NEMA 4X enclosure with a disconnect. I don't believe there are any fuses, however.

Saffa,

we don't put fuses inside the drive.
from the main power strip > fuses or circuit breakers (fused disconnects) > wire to vfd > vfd > fuses > wire to motor> field disconnect > wire to motor > motor.
i don't know why, but some of our older control panels has fused disconnects rather than fuses only.
james

James Mcquade said:

Saffa,

we don't put fuses inside the drive.
from the main power strip > fuses or circuit breakers (fused disconnects) > wire to vfd > vfd > fuses > wire to motor> field disconnect > wire to motor > motor.
i don't know why, but some of our older control panels has fused disconnects rather than fuses only.
james

Click to expand...

James, the fuses on the load side of the drive still confuse me. If they're not inside the drive, are they installed in an enclosure immediately under the drive or something? They seem unnecessary - The VFD should provide overload and short circuit protection to the downstream motor and cable.

Everything else makes perfect sense.

That's why i was wondering if this is one of those "Code" things that gets done because the regulations haven't caught up with modern drive systems etc. We have had plenty like that - and it even took a mining distaster to prompt a large revision, to a document that had had little change in nearly a decade.

I don't get fuses on the load side, either. Actually, I think it's a bad idea, since if one blows, the voltage spike could damage the drive...

One thing to watch out for with some of the drives that have an integral disconnect is the SCCR listing of them as a unit. Often times if they use an IEC style rotary disconnect switch, the SCCR of that device is only 5kA unless there are fuses, and if the fuses are not IN the unit with the disconnect, then you will end up having to add another fused disconnect ahead of it anyway.

jraef said:

One thing to watch out for with some of the drives that have an integral disconnect is the SCCR listing of them as a unit. Often times if they use an IEC style rotary disconnect switch, the SCCR of that device is only 5kA unless there are fuses, and if the fuses are not IN the unit with the disconnect, then you will end up having to add another fused disconnect ahead of it anyway.

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jraef, would the fused disconnect ahead of it just be to satisfy SCCR? The idea being it would lower the arc flash potential and allow someone to work on the device while live?