Re: Time to replace water pump, accumulator, fill valve...maybe more
Reply #28 –
Hey Still...
Amazons info on the Shurflo 4048153E75 Electric Water Pump says it has a back flow preventer. If the plumbing is correct seems like it should not flow backwards. Not good to be filling the tank when you don't want it to be filling.
I have noticed my LR LED pulse once for a fraction of a second when the water pump is turned on. I only notice it at night when all,the lights are off and the pump gets turned on. I have not solved it yet. In my coach the power for the ceiling lights on the slide side went through a relay above the MW somthat when the room was in those lights were off. The lights back in the kitchen area have a relay as well for the same function. When I added a LR light dimmer the relay buzzed so I bypassed the relay. Now all the LR lights are on even if the room is in but the dimmer works. So the question is how does the three way water pump switch set up work? They are all momentary contact switches. When the water pump is on the lights on all three switches are on. Probably a latching relay of some type. Closing any switch closes the relay if it is open or opens the relay if it is closed. Really not sure what happens next, why the indicator lights come on. I think something is goofy in the ground paths as it pertains to the dimmer. I should bypass the dimmer and see if it still happens. Just haven't had enough time.
Here is what Steve had to say ...
"I've seen many odd things in the 12V systems, really there is no earth ground, just a return loop, so when things get noisy it can effect quite a few things. Since the LED's are diodes they should only be on when current is flowing in the right direction. So for them to pulse you have to be getting a positive voltage of at least several volts at them.
Pumps / Motors will create quite a few spikes on the 12V line, they switch a lot of current and cause inductive kickback. When the motor's windings are carrying current, they generate a magnetic field. If the current is suddenly cut off, the magnetic field collapses and this will induce a current / voltage in the windings that is much higher than usual. It is very short lived but the values can be pretty high, this is often referred to as "back EMF" or "flyback".
The pump should be taking care of that, but sometimes a little extra help is needed. If you want to experiment, and who does not, you can placing suppression / "free wheeling" diode across the pump voltage leads or at the relay. Any regular rectifier diode should work. Just put the diode in reverse (diode anode on negative side of pump and diode's cathode (stripped end) on positive lead). When switch opens, the diode will dissipate the "flyback". Likewise a capacitor with a series resistor may work as well, sometimes called a snubber, it just trying to dampen the spikes and lengthen the time of the spike event."
Like a wild pictch at the ball game ... Right over my head. Still digesting, still trying. I wonder is this happens in the newer coaches with all LED lights and the fancy mulitplex control system.
My guess it that you need to have a clean ground path that is not in common with anything else other than the chassis. Maybe some big diodes here and there too. This is one that is tough to solve. I have LED lights in a cabinet (not where the (Genie is) that come on when I open the door. If the DirecTV Genie is on the HDMI signal gets interupted. Close the door, good to go. There is no 12v anything in the Genie. Steve thought it might be an RF pulse from the LED lights coming on but it doesn't happen when the LED lights in the cabinet where the Genie is located come on when that door is opened.
Don't stay awake at night thinking about it. Enjoy the LED lights.
Roger
Topic: Time to replace water pump, accumulator, fill valve...maybe more (Read 1886 times)
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