Pump House Questions

[Rcf]

I have to use a booster pump to get municipal water to my house.

The pump is a Myers that is convertible between 115 and 230 volts and set for 230 volts. I have run 10/2 wire to the pump, which is about 430 feet from the house. Everything works quite well; however, I need to keep it from freezing.

I want to put a light bulb with the pump. As opposed to burying another wire from the house to the pump, it has been suggested that I use one of the legs of the 10/2 wire to supply the light. To do so would mean that the pump will have one leg always hot (that would also be the electricity source for the light). The other leg would be energized when the pressure switch on the pressure tank calls for water. Would this cause a problem for the pump?

Secondly, I have placed the pump about 32 inches under ground to help with the freezing issue. I am curious. Is it better to have the pump at surface-level, or does it really matter?

Would really appreciate any help you can provide.

 

[Leejosepho]

I want to put a light bulb with the pump.

If you must add heat, I believe some kind of heat tape that is not so likely to burn out and that is engineered to maintain something like 40* would be better.

As opposed to burying another wire from the house to the pump, it has been suggested that I use one of the legs of the 10/2 wire to supply the light ...
Would this cause a problem for the pump?

I do not know, but I would suspect that would not be okay by "code".

I have placed the pump about 32 inches under ground to help with the freezing issue. I am curious. Is it better to have the pump at surface-level, or does it really matter?

Oh no, the deeper the better as far as avoiding freezing is concerned. Do you happen to know the depth of the frost line in your area? If your pump is below your frost line, you should only need to heat the pipe coming to the house at any point between the frost line and heated space.

 

[Sponsor]

 

[Speedbump]

You asked if you can use one leg of the #10 wire to supply voltage for a bulb. It would be OK if you have a neutral. Chances are, you don't and would want to use the Green Ground wire. This will work but is a big NO NO.

Usually when you buy wire for a given voltage you get three wires, Black, White and Green. This is great for 115 volts or 230 volts, but for both voltages you need one more wire, usually a Red one.

bob...

 

[Wet_Boots]

If you can dig down to below the frost line, you can get enough heat from the soil to protect the plumbing. A town I know of abandoned the use of double-cover meter pits, since the 4-5 foot deep pits were preventing freeze damage, even with the water meters within a foot of the manhole cover.

 

[Masterpumpman]

Freezing!

I'm not a licensed electrician and don't know the code. Check with an electrician before you try my suggestion.

I'm not an engineer, I'm a well driller, we look for simple solutions!

On a 230 volt line (2 wires) I would install two 40 watt 115 volt bulbs in series. If I'm really concerned with freezing, I would probably install four 40 watt 115 volt bulbs, each two in series. In the event one burns out the other goes out as well. That's the reason for 4 bulbs.

Porky

 

[Bob NH]

I don't know what the temperatures are where you live, but unless you are above latitude 45 you can probably insulate the pump in the pit. I would fill the pit with insulation protected from getting wet, and add an insulation-filled "dog-house" over it with a roof to carry away the rain.

When the pump runs the motor heat will add some heat in the pit.

A more technical solution would be to use the pressure switch at the tank to operate a relay and contactor set up to connect a DC source to the 10/2 circuit when the pump is not running, and to disconnect that low-voltage source and connect the AC power when the switch calls for water. A 1/2 HP 230 Volt motor will have a winding resistance of about 10 Ohms (measure it) and the wire resistance will be about 1 Ohm. If you put 2.5 Amps through a 10-Ohm winding you will put 62.5 Watts into the motor, which will heat the area around the pump. You can set up a simple power supply circuit to furnish the DC. The DC must be disconnected BEFORE the AC is connected.

No new wires are required and there is no change to wiring at the pump. You can check the temperature and adjust the heating voltage to get what you want.

 

[Gary Slusser]

This has to be a jet pump, and they usually have the switch on the pump so there will be power to the switch at all times.

If the hole is below the frost line, use Styrofoam insulation to make a box cover for the stuff in the hole. Otherwise see if you can find a 230v heat tape.

 

[Speedbump]

BobNH,

Are you suggesting he run DC current through the pump motor to be used as a heater??? This is an interesting idea, but a little dangerous should the relay go bad.

He would need an adjustable voltage/amperage power supply. Expensive.

If the relay were to go bad, the power supply would certainly be toast and he may have a fire to contend with.

bob...

 

[Bob NH]

BobNH,

Are you suggesting he run DC current through the pump motor to be used as a heater??? This is an interesting idea, but a little dangerous should the relay go bad.

He would need an adjustable voltage/amperage power supply. Expensive.

If the relay were to go bad, the power supply would certainly be toast and he may have a fire to contend with.

bob...

The best solution is insulation. That will work unless the climate is extreme.

You don't need an adjustable power supply for the heater. You need a transformer and a rectifier selected to give the desired voltage. If you want to get fancy you can pick up a used Variac on that famous auction site.

A DPDT relay to remove DC power and apply AC power will make it very unlikely that the AC will ever connect to the DC supply. If there is a failure then fuses will protect the system and prevent fire.

 

[Speedbump]

You need a transformer and a rectifier selected to give the desired voltage

A Transformer and Full Wave Bridge Rectifier is a power supply.

I still don't like the idea of applying voltage of any kind to the windings of a motor for the purpose of making heat. I'm going to stick with the light bulb.

bob...

 

[Gary Slusser]

Me either and damned sure would void warranty on the pump and could be a great liability for the guy doing it or suggesting it IMO.

And if insulation is placed below the frost line and above the pump, regardless where this is in the entire world, it will provide freeze protection.

 

[Rancher]

Actually in an inclosed area you don't need anywhere near the 62.5 watts that Bob was designing to.

You could have the pressure switch operate a DPDT relay or contactor, that would either connect the 240 vac to the pump when on, or in the off position of the pressure switch that relay could connect the output of a common off the shelf battery charger to that pump.

Battery chargers put out 14+ volts DC, readily available, almost indestructable.

That would give you around 15 watts, plenty to heat the motor and pump area.

And safe.

Rancher

 

[Speedbump]

What is happening to the motor windings, the start cap and the start switch that most pump motors have? I assume you are running this voltage directly in through the switch, so you wouldn't be bypassing them. I wonder how the overload protector would regard this DC voltage?

Better yet, lets try this on one of YOUR motors and see how it works first.

bob...

 

[Rancher]

What is happening to the motor windings, the start cap and the start switch that most pump motors have?

The 10 ohm motor windings warm up with the 14 volts DC going thru them, the start cap and start switch don't see any effect, the capacitor will charge up and block any DC current thru the start winding, it won't be stressed, as it is made to handle 240 VAC.

I wonder how the overload protector would regard this DC voltage?

The overload protector is a temperature switch, it opens on excessive temperature, 15 watts isn't going to do it.

Better yet, lets try this on one of YOUR motors and see how it works first.

Good idea, I'll post it on my web site right next to my test of the CSV...

Rancher

 

[Speedbump]

I'm not sure the Cap will charge up with DC. But it will block it.

How warm do you expect these windings to get?

Good idea, I'll post it on my web site right next to my test of the CSV...

I should have anticipated that statement.

bob...

 

[Bob NH]

I'm not sure the Cap will charge up with DC. But it will block it.

How warm do you expect these windings to get?

bob...

The heating (Watts dissipated) in a motor winding is proportional to Current squared x resistance. It doesn't matter whether it is AC RMS or DC. I would start with 50 to 70 percent of the current at the Service Factor Amps, which would produce 25 to 50 percent of the Watts dissipated in the winding at Service Factor load.

Service Factor Amps = Full Load Amps x Service Factor. (approximately)

The current should be limited and the temperature should be checked.

The heating in a static motor will not be the same as in a running motor because of iron losses and air-drag losses which add to heating. The temperature rise in a motor will be affected by the ventilation which will reduce the temperature in a running motor. There is very little ventilation in a static motor.

 

[Speedbump]

So you really are serious about doing this.

Geesh, I thought you were joking.

bob..

 

[Rancher]

Pump motor winding won't burn out with this trick, light bulbs will.

Rancher

 

[Gary Slusser]

Guys the motor doesn't freeze, the water in the other end of the pump does, and heating the motor windings isn't going to get to the other end or into the water. Or to the water line connections on the far end of the pump.

 

[Rancher]

Guys the motor doesn't freeze, the water in the other end of the pump does, and heating the motor windings isn't going to get to the other end or into the water.

What kind of wager would you like to make on that statement?

Or to the water line connections on the far end of the pump.

Boy you got me on that one, I guess we could let the faucets dribble a little and that will take care of that problem.

Rancher