Reversing switch for fuel transfer pump

[dhays]

I would like a solution to something that really isn't a problem.

I have a 12v Reverso fuel transfer pump in the crossover line between my fuel tanks. The reversing switch is a spring loaded toggle at the helm station in the PH. The pump doesn't pump that fast (I don't have the specs with me) and so if there is much fuel to transfer it can take quite a while.

The toggle switch needs to be held continuously to keep the pump operating. This is a very reasonable safety precaution so someone doesn't accidentally hit the switch and not realize it, or intentionally flip the switch and then walk away and forget about it, in the mean time fuel gets pumped out through the vent of the now full tank.

I get really tired of holding that toggle switch and so would like another solution. I would really like a reversing switch with an LED indicator. That way I could flip the switch and have a visual indicator that the pump is running. This would solve the stand-there-holding-the-stupid-switch problem, but leaves me vulnerable to the accidental or forgetful problems.

A timer would solve that forgetful problem. Tony Athens recommends this and suggests a simple mechanical twist timer such as you might find on a bathroom fan. This is a great idea but the only place where it would make a decent install would be back in the ER. That would mean having to open up the ER, get down in and over to the timer etc...

So, are there 12v timer switches? Something that could be pressed or flipped and then deactivate after a set number of minutes? I wouldn't even care if it was variable. It it would activate the pump for 10 minutes that would be great. It would be easy and clean to install those two switches where the current toggle switch is now.

I have looked, but electrical switch specifications tend to confuse my poor, weak, mind.

 

[JDCAVE]

Possibly not what you want but I have this setup:, which includes a spring loaded timer switch:

It has a timer, but I usually keep a close eye on it. The manifold directs the flow from tank to tank.

Jim

 

[dhays]

I would love that setup Jim. I just don't have the room to completely redo my fuel system to something like that.

 

[Lou_tribal]

Or more difficult but error proof, a tank level switch that would bypass your command switch and cut the pump in the event you were watching a so good movie that you forgot to turn it off
But I guess it must be difficult to put this in place so forget it !

 

[Ted]

My freight truck has a mechanical timer switch for the lights
in the cargo box.
Twist the dial to the minutes required and finish the job,
close the door and walk away, the timer will shut the lights
off.
Should be able to get one at an auto supply or truck shop.

Ted

 

[dhays]

My freight truck has a mechanical timer switch for the lights
in the cargo box.
Twist the dial to the minutes required and finish the job,
close the door and walk away, the timer will shut the lights
off.
Should be able to get one at an auto supply or truck shop.

Ted

Yup, I had thought about a mechanical twist timer. The problem is that I don't want it mounted at the helm due to aesthetics and don't want to have to go into the ER to set it.

I thought no the answer will be a timer delay relay. I just need to figure out how to wire the relay on a reversing switch.

 

[Northern Spy]

You could wire in a 12v adjustable timer relay and use your existing switch .

 

[dhays]

You could wire in a 12v adjustable timer relay and use your existing switch .

The toggle I have is a DPDT reversing polarity momentary switch. I don't know how I would be able to wire a timer relay with that. My understanding of circuits is really poor.

The only thing I could think of is use a timer relay with a momentary push button trigger switch. Then I could replace my current toggle for a maintained DPDT reversing toggle. The relay would be wired ahead of the toggle.

To transfer fuel I would;
1. Turn on the DC circuit to the pump. This would activate the control voltage to the relay.
2. Use the toggle to select the desired direction of the pump.
3. Press the momentary button trigger. This would start the delay off timer. After the time set in the relay, the relay would open and the pump would quit.

If I wanted another interval of fuel transfer all I would have to do is press the momentary button again.

If I didn't need to use a reversing switch it would be easy to wire in a timer relay controlled by my existing momentary switch (I think).

 

[twistedtree]

The toggle I have is a DPDT reversing polarity momentary switch. I don't know how I would be able to wire a timer relay with that. My understanding of circuits is really poor.

The only thing I could think of is use a timer relay with a momentary push button trigger switch. Then I could replace my current toggle for a maintained DPDT reversing toggle. The relay would be wired ahead of the toggle.

To transfer fuel I would;
1. Turn on the DC circuit to the pump. This would activate the control voltage to the relay.
2. Use the toggle to select the desired direction of the pump.
3. Press the momentary button trigger. This would start the delay off timer. After the time set in the relay, the relay would open and the pump would quit.

If I wanted another interval of fuel transfer all I would have to do is press the momentary button again.

If I didn't need to use a reversing switch it would be easy to wire in a timer relay controlled by my existing momentary switch (I think).

I think that would work. There are programmable delay relays available in DIN rail package. Check out Newark.com. A programmable relay will be a bit expensive - probably $75 - but I think will give a nice solution that works as you describe.

 

[Bruce B]

I can't remember the details but American Tug uses a switch for their holding tank pump out that utilizes a timer. Even though they have changed to a diaphragm type pump that is not damaged by running it dry they have kept the switch in the system.
I believe it is a circuit they build themselves...
You might ask Kurt Dilworth there.
Bruce

 

[Ski in NC]

If you want to stick with the mechanical timer knob, you can mount it under the helm near an access hatch within easy reach. That should keep it dry and reliable.

On the 90' I worked on, it had the transfer pump timer knob in the engine room. It was 30yrs old and worked fine. And that engine room certainly had evidence of humidity exposure. I think max was 20min and that moved about 200gal. There was also a flow totalizer typical of a farm fuel dispenser in the line, also original and also worked fine. The pump was farm dispenser type also, nothing marine spec in the system. Pump was not reversible, but had a fully valved manifold that could change direction.