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15 hp vfd for 5 hp motor on compressor

rons

Diamond
Joined
Mar 5, 2009
Location
California, USA
The volume is 120 gal so the motor is on longer than for a smaller tank. Should I use 15 Hp and not 10?
For $100 more the components are rate 50% higher.

10 Hp.

15Hp.

15Hp that costs less than the Wolf 10Hp. $150 less than the Wolf 15Hp. How can they do that?
 
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If 3 phase input VFD then you want the VFD output amps minimum to be above the motor FLA. If running a 3 phase input VFD off of single phase then the derating is brand/model specific and also effected if you use a DC choke. The Fuji mini series VFD is often are used as a cost effective VFD, general derating for running a three phase input Fuji VFD is to divide the output amps by a factor of 2. This varies greatly these days on many VFD's and also on the application and deratings. Buying older or surplus VFD's can be an issue in that the capacitors can fail when powered up if a VFD has not been used for years, some have the programming locked or burned into a specific VFD and cannot be changed. Certain surplus models may be for specific geographic regions, etc. There are also single phase input 5Hp VFDs like the Yaskawa GA50UB018ABA or Invertek ODE-3-320153-1042 which is probably the simplest option for single phase input 5Hp unit. I use quite a few of the Yaskawa drives through the years, their latest GA500 series works very well and is cost effective for this type of application. The GA50UB018ABA is quite large and wide, it has an output current of 17.6A three phase in HD mode. HD mode is up to 100% duty cycle in constant torque.

Fuji FRENIC-Eco series a 10Hp three phase input (010) would have a 5Hp (17A) output rating on single phase
1709306843433.png
Yaskawa GA500, if using a 3 phase model on single phase you would need to use the GA50U2042ABA with a DC choke to get the same output ratings as the GA50UB018ABA
1709307647277.png
 
Oh... Now I have to read all that stuff. I don't like shopping for vfds.

Side questions:
Does it make sense to use a vfd rated for fan/pump on a compressor?
Does it make sense to up the requirement from 10 to 15 Hp for reliability? Cost difference is almost nothing.
 
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Fans and pumps are variable torque, piston air compressor is constant torque. Ratings are different, but VFD's are usually rated for both variable torque and constant torque, as well as ND and HD. A piston air compressor would be HD. No it does not pay to oversize the VFD if is a mainstream (industrial) rated VFD. The cheaper generic ones you often needle to double the size, and even with that they have a high failure rate in this type of application. A 5Hp three phase motor is typically in the 13-15A FLA, most 5Hp rated VFDs will output at least 17A in HD (constant torque mode), variable torque is usually higher. There are other derating factors and operating conditions to consider, but for the most part VFD drives in HD mode are rated for continuous operation. When sizing the a VFD I usually look that the output current is at least 10% higher than the motor FLA, but I also factor in the application and brand/model of the VFD. Fuji, Yaskawa, Hitachi, Invertek, etc. are all mainstream VFD's, a 5Hp rated output model (HD) should be fine in this application. Be careful in that VFD's may be rated for different Hp/output amps depending on the operating conditions so in variable torque a VFD may be rated for much higher Hp/A vs. constant torque (HD). You still have not specified if you are running the VFD off of single phase or 3 phase input, and the motor specifications.
 
There are also single phase input 5Hp VFDs like the Yaskawa GA50UB018ABA or Invertek ODE-3-320153-1042 which is probably the simplest option for single phase input 5Hp unit. I use quite a few of the Yaskawa drives through the years, their latest GA500 series works very well and is cost effective for this type of application. The GA50UB018ABA is quite large and wide, it has an output current of 17.6A three phase in HD mode. HD mode is up to 100% duty cycle in constant torque.
They claim to be 30% smaller than the competition.
 
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Any of the VFD models mentioned would be more than adequate for your application, I would recommend either the single phase input 5Hp models Yaskawa or Invertek so you do not need to worry about adding a DC choke if using a 3 phase input VFD in derated mode. Cost wise they are all very close to the same, the Yaskawa GA50UB018ABA at $635 would be my recommendation. I use their software to setup the VFD with a USB cable, the Invertek are a bit easier to setup. You would wire the VFD forward run low voltage input to to your pressure switch.
 
Thanks for the answers. The only thing is:

I'm having a tough time trying to like the packaging on theses drives. Should get somebody like Shelby to design the boxes.
 
I must be missing something, if you like the look of a different VFD like the Invertek go with that model. They also have sealed models with a power disconnect switch. Otherwise mount it in a steel box electrical box and close the door. I do not vent the enclosure if it is of sufficient volume.
 
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If I wanted to derate a 10hp to 5hp, no good on this size 4.


Please note: For IP66/NEMA 4X three phase input models, chassis size 4 is not capable of being derated for use in applications supplying single phase power to these units.
  • Size 4 chassis use film capacitors which prohibit single phase operation.
 
I must be missing something, if you like the look of a different VFD like the Invertek go with that model. They also have sealed models with a power disconnect switch. Otherwise mount it in a steel box electrical box and close the door. I do not vent the enclosure if it is of sufficient volume.

A TFT display makes programming easier?
This price is $1344.
The Yaskawa is $635.
 
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Download the Yaskawa software, plug your USB cable into the VFD and you have as big a display on your computer. There would be very few parameters to change in either case, basically the motor specs, acceleration time, cancel the deceleration braking and probably motor auto tune. Its your money how you want to spend it. The NEMA 4X/12 may have different ratings. Yaskawa GA800 VFD's come with a TFT display, only available in 3 phase input at 3-4X the cost of the GA500 series.
 
The Hitachi WJ200 single-phase in models only go to 3 Hp. So I looked at this 10 Hp model for my 5 Hp need.

Hitachi:
(Shows the slim model)

Invertek:

Yaskawa:

It's hard not to like the low price and small size of the Yaskawa. I keep trying.
 
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They are all very good VFD's, and way more than one would need for the application. That price on the GA50UB018ABA is much lower than other vendors, most of my VFD system builds these days, I am using the Yaskawa GA500 VFD's. But in this application I would go with the Invertek ODE-3-320153-1F4A-EIP with a NEMA4X enclosure at $847 and be done with it. They are dead simple to program and setup, they have very good tech. support.

Yaskawa GA50UB018ABA, close the enclosure door and they all will look the same.
GA-500.jpg
Yaskawa GA500 15-20Hp VFD
Yaskawa GA500 15-20Hp VFD.jpg
 
Hey Ron,
A buddy of mine just moved into a shop with 3 phase and would sell his 10 hp phase perfect if you are interested. I can attest it works as it should. it is an older blue unit and he told me he needs $2000 for it. I wanted it untill I found out iit is only 10 hp, (I need 15 or maybe 20).
If you are interested I can put you in touch with him, he is in San Luis Obispo, today is the last day of his move out. I think he also has a small metal shelf they made so it can mount up on a wall.
 

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I have so much time in metal cabinet fabrication that only a VFD will fit.
I have to think about if I'm worthy of a PP. I have been looking at vfds for a week. Each day I have a new favorite.
 
There is no reason to go with an oversized VFD that is single phase rated input and the output meets the motor FLA. Most mainstream VFD's like the Yaskawa have a MTBF of 27+years, it will probably outlast us. If you are going with a 3 phase input VFD running it on single phase, then the derating is a factor of the specific model and conditions that the manufacturer specify. Over sizing by a factor of 2X is a general criteria these days, but many newer VFD models require the addition of a DC choke. Yaskawa drives require the use of a DC choke to meet a derating of 2X otherwise it is more like 3X (I am doing a current 5Hp motor install 1P or 3P input using the GA50U2042ABA with a 40A DC choke). Since it is going in an enclosure, why do the looks matter? I am have done numerous installs with these VFD's, for a 5 Hp motor I would keep your money and go with one of the following:

Invertek ODE-3-320153-1042 (single phase input, no derating and the simplest install for single phase input VFD 5Hp)

Hitachi WJ200-075LF (3 phase input run in derated mode and does not require a DC choke), I see no reason to spend more money on the Hitachi P1-00460-LFUF

Fuji Electric FRN0047C2S-2U (3 phase input run in derated mode and does not require a DC choke, but it will reduce input peak amps)

There are many more. Yaskawa GA50UB018ABA single phase input if it fits. This is and always has been the current model for this GA500 VFD, the posted pictures usually are not that of the actual VFD. You need to look up the measurements for the VFD model you are interested in.
RIP:willy_nilly:
 








 
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