Well Pumps - Variable Speed?

[buickanddeere]

There are VFD drives for single phase three wire pumps. Another a advantage of the VFD is that it can increase pump rpms above 60HZ for high flow, low pressure demands.depends on how well the submersable pump was sized to the application . Not unusual to find a pump with many stages installed shallow and a pump with too few stages placed too deep.

 

[Professor Marvel]

This VFD on a well pump is an interesting idea. There have got to be more parts to fail e.g. pressure sensor and controller. Pump should last longer due to soft starts (but well pumps last pretty long in my experience anyway). Personally it seems to me that the way to go is with the standard single speed pump with a pressure switch but add an oversized pressure tank as drajj suggested.

 

[TheGoose]

Just my personal opinion as a Tx licensed water well driller and pump installer for 20 years...

A vfd is a computer controlled device. They have advantages in some situations. A CSV is an alternative to a vfd. The electricity is a non-factor. A standard well pump does not use more than 10-15$ a month of electricity.

My advice is to use the smallest well pump that will do the job and couple it with the largest well tank you can afford. Most people use a larger pump than necessary and that causes excessive cycling.

 

[Silvic]

Just my personal opinion as a Tx licensed water well driller and pump installer for 20 years...

My advice is to use the smallest well pump that will do the job and couple it with the largest well tank you can afford. Most people use a larger pump than necessary and that causes excessive cycling.

TheGoose

With your experience then I have a question or series of them.

Due to code I have to put a fire suppression system in the new house we are going to build.

Option A I can put a large pump set deeper and get the flow I need.
or
Option B I can put a smaller pump say 5-10 gpm set more shallow (dynamic level at 10 gpm is a little bit higher than at 50 gpm) and put in a 2000-3000 gal tank with another pump which is high gpm to supply the system.

Option A the well pump is more expensive with more copper in the hole (set deeper) but less complex as only one pump and no storage tanks.
Option B has a cheaper well pump but the extra tanks and extra high flow pump are not cheap.

Either way would have a pressure tank for the system.

Money aside which do you think is better in the case as I describe it?

Tradeoffs for certain but what is your opinion as a long time pump installer. I have had installers give me absolutely positive answers both ways.
They each think there is only one way, their way, each one being the opposite of the other.

By the way the well can support either option. Required flow is 50 gpm.

 

[TomSeller]

Just my personal opinion as a Tx licensed water well driller and pump installer for 20 years...

A vfd is a computer controlled device. They have advantages in some situations. A CSV is an alternative to a vfd. The electricity is a non-factor. A standard well pump does not use more than 10-15$ a month of electricity.

My advice is to use the smallest well pump that will do the job and couple it with the largest well tank you can afford. Most people use a larger pump than necessary and that causes excessive cycling.

I agree with this. Also install as small of a hot water tank as can get away with. Keeps the shower-time down. My wife is one of those that gets out of the shower when the hot water runs out. Each time the hot water tank needed to be replaced (been here a long time), I went one size down. She asked if I would install an instant whole house hot water heater... I declined.

 

[Xfaxman]

Someone else told me to get a CSV (cycle stop valve) on a standard pump. These valves keep constant pressure and reduce pump wear. This would be option #2 for me.

I have a CSV with the pressure tank in the well casing and really like it.

I added a light that comes on when the pump runs and that has been very beneficial.

Quite aways into this thread is where the CSV is explained: http://www.tractorbynet.com/forums/rural-living/271589-water-well-pump-monitor.html?highlight=

 

[Sprinklerman]

I install residential lawn irrigation , when I get to a house with the variable speed pumps , its GREAT . Sprinkler heads work perfectly . AND they can take a shower or bath at the same time .

 

[Professor Marvel]

I install residential lawn irrigation , when I get to a house with the variable speed pumps , its GREAT . Sprinkler heads work perfectly . AND they can take a shower or bath at the same time .

Yes I would guess that with irrigation and sprinkler applications this technology would shine

 

[TomSeller]

. AND they can take a shower or bath at the same time .

Having a VFD on the pump alone is not going to allow the sprinklers to run and take a shower at the same time. The pump would have to be larger.

 

[drajj5]

I agree with this. Also install as small of a hot water tank as can get away with. Keeps the shower-time down. My wife is one of those that gets out of the shower when the hot water runs out. Each time the hot water tank needed to be replaced (been here a long time), I went one size down. She asked if I would install an instant whole house hot water heater... I declined.

I would do this...... however my wife would kick my butt. You see, 'a happy woman= a happy man'. In return I get free delivery of beer and sustenance on a daily basis.