Do not have any direct experience with this VFD/brand, but as mentioned Wolf Automation is a reputable supplier and you would have good support post sale. The VFD manual is well written, and all though it does not have all the bells and whistles of some of the more expensive VFDs, it will be fine for the application you are interested in. That particular VFD model is a 10 Hp 3 phase input, so it is being derated for single phase input, and in its default setting phase loss detection is deactivated. You will need to have a service/breaker which is 125% of the rated single phase input, not the motor rated value. So I would discuss this with Wolf Automation to make sure you have sufficient panel/breaker for this size VFD. There are very few 5 Hp single phase input VFDs, most which are more expensive. Typically what is done is to derate a 10 Hp three phase input VFD if the phase loss circuity can be deactivated. You will need an external braking resistor in this application. One interesting feature of this VFD, which is usually not seen at this price level, is user replaceable capacitors (p220 of the manual). The time interval of 4 years is usually based on 24/7 and factors in load and operating temperature, so in lighter duty use I would expect 2-3X the longevity. Hitachi is something like 7-10 years, Yaskawa is longer. Below is the single phase input 5Hp version that I have used before, they are often used with factory supplied mills and lathes for 5 Hp machines. You could squeeze by with a 7.5 Hp 3 phase VFD with a DC bus choke in this application which is lighter duty.
Yaskawa AC Frequency Drives In-Stock. State Motor & Control Solutions. Shop Online
ODE-3-32153-142, 23V 1 Phase input, 23V 3 Phase output
WJ2-55LF 7.5HP 5.5kW 23V VFD - Hitachi
Most of the other VFDs single phase 5 Hp or 7.5/10Hp three derated will run $500-800 for mid level quality VFD.
Good post, thanks!
On the capacitor bank longevity "estimates":
- True that when used on clean 3-P one can expect lighter duty to be accompanied by longer life expectancy.
- There is an "upper bound", as already covered in several other PM threads. The life expectancy has a chemical ageing component, such that even if left on the shelf, the basic chemistry of the electrolytic capacitor eventually degrades it. Not all have identical chemistry. Chemistry, or subtle nuances of it, changes by maker, and has changed over time as technology has changed. This makes purchase of older VFD, even if "NOS" a gamble.
- The "wear" component is affected by how rudely the ripple stresses the capacitors, and how extreme their excursion between working charge levels, each cycle. This "swing" is naturally much higher when operated off single-phase than it is for the evenly balanced 3-Phase.
A result is that whilst a VFD's capacitors might live much longer than "worst case" when in pure 3-Phase service, they are HIGHLY unlikely to enjoy that blessing when used on single-phase input.
For de-rated use on single-phase input, it is better to plan for the "book" life expectancy, and be happy to reach it or exceed it by a more modest margin, not a multiple.
VFD specifically built for 1-Phase use generally apply upsized capacitors and rectifiers that can stand greater thermal imbalance, longer. It is a "form of" derating in that they do not necessarily have to have all the OTHER parts of the VFD built to the higher HP specifications.
Think 10 HP "front end" on a 5 HP VFD instead of 10 HP "all over" VFD derated to 5 HP.
Not to forget, there is more to it than Phase-loss detection/NOT or "rule of thumb" 50% de-rating.
Some VFD makers have used components and design approaches that require greater de-rating than others - as much a 70%. Some are not comfortable with de-rating for single-phase use AT ALL. Others include figures "right up front" for single-phase use, as it has become such a common need especially for under 10 HP loads, more common-yet at 5 HP and almost a "given" want at 2 HP and below.
One MUST find and respect the maker's recommendation in the model and revision-level specific manual, as it can change over time, same maker.
Wolf are among those reputable vendors who tend to do this sort of research FOR their customers as they make their business choices as to which products to carry at all, and what applications to recommend them for.
I'd class that as "good business", but not all vendors do that.
2CW
