Noisy VFD

Users who are viewing this thread

Brett Jenson

New Member
Messages
4
Reaction score
0
Points
1
Location
Portland, Oregon
Hi,

We are remodeling a house and installed a 3 phase, 5 HP pump and VFD. We finally have the house all insulated and sealed up with all the doors and windows fully installed and painted, and the pump is running. However it is way louder than I expected, probably as loud as a small hotel hair dryer. The house is a 3000 square ft daylight basement and the VFD is in a basement room, in a closet, and I can hear it in every room of the basement with multiple walls in between.

Is this normal?
 

Valveman

Cary Austin
Staff member
Messages
13,240
Reaction score
920
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
Hi,

We are remodeling a house and installed a 3 phase, 5 HP pump and VFD. We finally have the house all insulated and sealed up with all the doors and windows fully installed and painted, and the pump is running. However it is way louder than I expected, probably as loud as a small hotel hair dryer. The house is a 3000 square ft daylight basement and the VFD is in a basement room, in a closet, and I can hear it in every room of the basement with multiple walls in between.

Is this normal?
Yes that noise is normal from a VFD. Unfortunately it is just the first of many problems you will experience with a VFD over the years. The worst part is that you will have to pay dearly to replace that noisy VFD every 2-5 years. The idea of varying the flow rate to produce constant pressure is the only good thing about a VFD. Besides being noisy, they cost a lot, don't last very long, shorten the life of pump/motors, greatly increase your energy use for water, and sit there using 40W of power even when the pump is off.

Don't get me wrong. Constant pressure from a VFD is great if you don't mind paying a lot extra and being out of water several times over the years waiting on a replacement VFD or a short lived pump/motor. Most people just keep paying and putting up with the down time as they don't know there is a better option. But people who like constant pressure and are just tired of paying through the nose to keep a VFD system running find Cycle Stop Valves as the perfect solution.

The CSV itself doesn't use any electricity, doesn't make any noise, is much less expensive than a VFD, and can make everything in a pump system last 30-40 years. That last part is why pump manufactures blacklisted the CSV back in 1994 as it is disruptive to the entire pump industry. I think a lot of people are happy with their VFD because they don't know any better and just think regular pump and VFD replacements are normal. Funny that they usually replace that noisy and expensive VFD about three times before they start looking for an alternative and find the Cycle Stop Valve.
 

Brett Jenson

New Member
Messages
4
Reaction score
0
Points
1
Location
Portland, Oregon
@Valveman

Can I bypass my noisy VFD and just power the pump?

I have a new 35gpm pump with a 5hp 3 phase 1500# thrust Franklin motor.

This seems to be the same pump setup as the traditional quote I received but the traditional quote was a single phase motor.

I have a pressure tank from the old system but I understand this wouldn’t be needed with a CSV.
 

Valveman

Cary Austin
Staff member
Messages
13,240
Reaction score
920
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
@Valveman

Can I bypass my noisy VFD and just power the pump?

I have a new 35gpm pump with a 5hp 3 phase 1500# thrust Franklin motor.

This seems to be the same pump setup as the traditional quote I received but the traditional quote was a single phase motor.

I have a pressure tank from the old system but I understand this wouldn’t be needed with a CSV.

Sorry. Once you make the decision to go with a 3 phase motor you are pretty much committed to using a VFD and to replacing the expensive VFD very often. You house power is only single phase and you would need a normal single phase motor to run straight on house power. The VFD converts single phase into three phase so they can use a 3 phase motor, which is required for most VFD controllers. As I said, this pretty much locks you into having to replace the VFD regularly until you decide to pull the pump and change out the 3 phase motor to a regular single phase motor. This makes a VFD kind of like a Tar Baby in that it is hard to get rid of.

Usually after people have replaced that $2000 VFD two or three times they will decide it is time to change back to a normal single phase motor. With a normal single phase pump/motor you can either use a huge pressure tank or a Cycle Stop Valve and a smaller pressure tank, and have something that will last 20-40 years without any more maintenance. Of course that is exactly why pump manufacturers and some pump installers push VFD's. They make more in the first 5 years on a VFD system than they do in 20 years with a regular pump with a pressure tank and adding a Cycle Stop Valve can double the life to 40 years. It is easy to see why pump guys are pushing VFD's and try to keep you from finding out about CSV's.

If you use what the pump guys want you to have, you will get a new VFD every couple of years. If you research and do exactly what the pump guys don't want you to know about, your CSV system won't need a dollars worth of maintenance for the rest of your life.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks