Dumb Question

Hi,
Do you need to turn on warter pump if you have water connection at camping site?

Thanks.

[Leslie & Nick]

Originally Posted by M3 Rules

Hi,
Do you need to turn on warter pump if you have water connection at camping site?

Thanks.

No. Just hook up to the exterior 'city water' connection. You don't need the pump. The pump is used to pump water from the fresh water tank when 'dry camping' - aka ''boondocking'.

[B_and_D]

You should also invest in a pressure regulator for your city water connection. Most places don't have high pressure, but some do, and it can cause your plumbing to spring leaks (not a good way to spend your vacation). It's better to be safe than sorry, and they aren't very expensive. We just leave ours hooked up to the end of our H20 hose.

http://www.campingworld.com/shopping...rs-gauges/4411

Install the pressure regulator on the TM end of the hose and not at the water spigot. You are much less likely to forget it when you pack up especially in inclement weather.

[ShrimpBurrito]

Originally Posted by M3 Rules

Hi,
Do you need to turn on water pump if you have water connection at camping site?

And if you do, the TM manual says you may damage your pump.

Dave

I put the regulator at the spigot, not at the TM. The reason for this is that the hose itself can spring a leak if the pressure is too high. But I do admit I've been tempted with the permanently installed regulator idea...and if I did that I'd just risk the hose.

[Wavery]

I don't know about others but I've gone through a couple of regulators this year. I always keep a spare now. It seems like they only last a few camp-outs and they seem to get plugged up and stop working.

I've even lent my spare to others in our camping group who have had their pressure regulators fail.

Originally Posted by ShrimpBurrito

And if you do, the TM manual says you may damage your pump.

Dave

How would the pump be damaged?

[ShrimpBurrito]

I'm not sure, exactly. I admit I have tested it for about a minute, and although my pump survived, it made disturbing noises. Definitely abnormal.

No part of the pump moves more than 1/8"....it is not a typical impeller design. If I understand correctly, during normal pump operation, there is a plastic plate that sits atop 3 adjacent chambers, and the plate rocks back and forth to create pumping action. Here's a diagram.

Obviously, the pump creates water pressure. Perhaps when there is back pressure into the pump outlet, the cumulative pressure created by the pump and the back pressure from the shore connection is enough to dislodge or rip the seal. I don't know, I'm just guessing.

Dave

[Bill]

As shown in this diagram and in the diagram Dave referenced, there is a one-way check valve at the output side of the pump. This prevents the city water source from trying to force water backward through the pump. A good idea. But ...

If city water is connected, the pressure closes the check valve. If you start the pump, then the pump is pumping against the closed valve. In other words, the water can't move. If this were an impeller pump, the impeller would simply spin in the pool of water in the pumping chamber, and no harm would be done. But this is a positive displacment pump. The motor goes around, and the wobble plate pushes against the rubber diaphragm, and the diaphragm has to move. But it can't move, because there is a solid column of water beyond it, and that water can't move. And water is incompressible. So the diaphragm has to move, but it can't move. Something has got to give. Either the motor stalls, since it can't push the diaphragm. Or the diaphragm rips. This is one disadvantage of a positive-displacement pump.

All of that assumes that the city water pressure is high enough to keep the valve closed. If city water pressure is lower, the pump may be able to force the valve open when the diaphragm is pushed. In that case, the pump will actually move water, and nothing will be hurt.

Did that make any sense?

Bill