Options on a VFD

[Open Neutral]

....not sure if that Franklin spec is going to accept a simple Load Reactor (assuming here that you have a Franklin pump and need to make sure you follow their recommendations). You can contact a distributor for TCI (Trans Coil Inc) or MTE for load filters; regardless of where you buy them most of the ones on the market are actually made by one of those two companies.

Thanks. I have also found AquaPhase and Add-a-Phase as possible alternatives but need to do more reading.

 

[Jraef]

Thanks. I have also found AquaPhase and Add-a-Phase as possible alternatives but need to do more reading.

The Ronk requires that you make absolutely sure the output is balanced, otherwise you must de-rate the motor. If you think that might be problematic, I wouldn't go that way.

The AquaPhase is a larger version of an already used technology called a Voltage Doubler. Many VFD manufacturers use it on small VFDs so that you can plug them into a 115V outlet and get 230V 3 phase for a motor. There are several people out there like AquaPhase doing this for larger motors as well, but there are problems with it, that's one reason why you don't see the major mfrs doing it. The number one problem is, as you will notice on this one, they are very difficult to get UL listed. In fact I don't know of one that is UL listed for 240-480V conversion. One problem with it is that the voltage doubler is essentially "external" to the VFD portion (even though it's in the same box, it's a separate circuit). In that unit, the output is around 678VDC, and UL considers anything over 600V as "Medium Voltage", which falls under a completely different class of rules. VFDs do this internally, but by keeping it all in the same circuit, they get away with it. It's a technicality, but an expensive one for the mfrs.

If UL is not a requirement for you, you may want to pursue it. But a LOT of small VFD manufacturers have come and gone in the last 25 years. People who have products install from the "gones" are stuck holding the bag on support and repairs. There is another version of this concept from a company in the UK called Drives Direct that uses a standard Teco VFD as the basis and adds that Voltage Doubler. But they too cannot get UL on it, so they don't sell many in the US.

 

[iwire]

So you're willing to admit that you can't see how complex the question is when ALL the possible data is supplied?

How about this, the data was supplied in post 8 and you were too self absorbed to see it.:grin:

 

[ptonsparky]

Go to http://www.franklin-electric.com/americas-water-systems.aspx and download the AIM Manual. Just about all you need to know. Use the load reactors as the VFD suggests (don't think it hurts to use them anyway but not sure) and make sure the pump hits at least 30 hz in .5 seconds and your good to go.

 

[Open Neutral]

Thanks for the heads-up on the AquaPhase and Ronk. I was skeptical since they were less then forthcoming on the magic within same. Voltage doublers used to be common on B+ power supplies, if anyone remembers vacuum tubes, but I'd not seen such elsewhere. It's interesting such is OK in EU-land, historically far more rigid in safety regs than us/US.

I have the AIM open in front of me, that's where I found the section I quoted earlier.

 

[wawireguy]

I'm curious how come a three phase pump was installed on a location with a single phase service.. There's more to this story..

 

[weressl]

How about this, the data was supplied in post 8 and you were too self absorbed to see it.:grin:

Look at the time-stamp before inserting foot...

 

[Open Neutral]

I'm curious how come a three phase pump was installed on a location with a single phase service.. There's more to this story..

We wanted 3ph 480 for the house and attached indoor pool. We'd planned the electrical system around such, inc. solar inverters and BU generators.

You have to prove the well and pump can deliver the required water flow before you even start the application process for a building permit. So it went in early on, with the 24H test on a generator.

But the AHJ was giving us a hard time on the 480 in a residence, and the costs to get any 3ph from PG&E went from the expected "guy with gun wanting your wallet" to "Inside guy with gun wants ALL..." levels. My client finally said "$60,000 is a lot of money.." and we started at the 20 yard line again.

 

[Open Neutral]

make that "Insane guy with..."

 

[Jraef]

We wanted 3ph 480 for the house and attached indoor pool. We'd planned the electrical system around such, inc. solar inverters and BU generators.

You have to prove the well and pump can deliver the required water flow before you even start the application process for a building permit. So it went in early on, with the 24H test on a generator.

But the AHJ was giving us a hard time on the 480 in a residence, and the costs to get any 3ph from PG&E went from the expected "guy with gun wanting your wallet" to "Inside guy with gun wants ALL..." levels. My client finally said "$60,000 is a lot of money.." and we started at the 20 yard line again.

Yeah, 480V for a residential service is a bad idea. For one thing, any 3 phase service from PG&E is going to come with something most homeowners will HATE to see and not understand; kVAR Demand Metering. So they will see their bill at the end of the month, then they will see the 1.632 kVAR demand penalty multiplier and say "What the Eff is THIS??!!"

A little side "gotcha" that an acquaintance found out later when a breaker failed on him on a Saturday: you can't get replacements at Home Despot...

 

[Open Neutral]

Yeah, 480V for a residential service is a bad idea. For one thing, any 3 phase service from PG&E is going to come with something most homeowners will HATE to see and not understand; kVAR Demand Metering.
...
you can't get replacements at Home Despot...

PG&E insisted there would not be same; I asked several times. They made no promises re: OTC for the installation.

As for the breakers; we'd have spares....This is a site with 2 backup generators; one padmount, one PTO, and oh a 5KW portable. And the inverters/solar. The meadow doubles as a helipad for CalFire during wildfires....

But I do have a question I ponder. The quote above from Franklin makes the point the dv/dt is an issue only if you have >50' between the VFD and the load.

I am trying to grok why. I was thinking the longer the length, the more shunting capacitance. In telco outside plant, that long local loop is a distributed low-pass filter; too long and your DSL, ISDN, or even dialing fails; that's why we have DTMF.

Now clearly this is not significant with 10 gauge/700 ft [vs 24 gauge/18K ft....] so is the issue the series R drop, or something else I'm not accounting for correctly?