Sump pump relay strange behavior.

Status
Not open for further replies.
I'm thinking that they printed, use a separate circuit for control and load power because the inrush screws up the cheap control circuit.
Add 1-1 xfmr, caps, diode on the control, relay bounce?
How long have the controls been there?
Are you pumping ground water or surface run off, been raining a lot? As in many cycles.
 
Mustwin351 said:
Great thoughts Jap and enjoyed your analysis. As far as I can tell from looking at the board and the incomplete wiring diagram provided that there is no electronic overload. The only overload protection it has are two 2 amp fuses. One for the alarm and one for the control circuit.

The link again for the diagram: https://www.grainger.com/ec/pdf/2PZG2_1.pdf
Click to expand...

Without any one there to witness it, I was thinking maybe instead of it not working at all,the pump may have operated for a while, then kicked out.

The only reason I asked if the alarm was sounding was to ,in a round about way ,check that the wiring to the floats were made correctly since it seems very odd that 2 different systems are having the same issue at 2 different locations.

Let us know.

Jap>
 
The alarm was working on the new one I installed. The other unit I’m not sure if it had an alarm but it did have an incandescent lamp most likely burned out.
 
gar said:
181013-2429 EDT

Mustwin351:

In post #29 you said the start and stop floats are wired in series. Can not be, won't work.

.
Click to expand...

I mispsoke. The most likely option is the stop is in series with the start and the start being in parallel with holding contacts and the relay coil. Basic 3 wire control. My description of it is not the best
 
sameguy said:
I'm thinking that they printed, use a separate circuit for control and load power because the inrush screws up the cheap control circuit.
Add 1-1 xfmr, caps, diode on the control, relay bounce?
How long have the controls been there?
Are you pumping ground water or surface run off, been raining a lot? As in many cycles.
Click to expand...


It has rained more than ever this last month for my area and the pumps are getting a good work out.

The installation instructions do recommend separate circuits for the control and the pump. Which I would like to do but don’t have the time. I figured the separate circuit recomendation was only in the event that the pump trips the breaker there would still be power to the alarm circuit.

If the relay was continuously bouncing something would burn up or the fuse would blow I would imagine.
 
181014-1352 EDT

Mustwin351:

A troubleshooting approach that might help you when you lack detailed information on the circuit.

Try to figure out how you would make a circuit to do the intended function. Here we have a pump down job with two floats, high and low. Since the important failure is in automatic operation ignore other things the circuit can do.

Generally you want to avoid edge triggered operations. For example a pulse from the time a switch changes state vs the actual state, on or off, of the switch.

Whether the pump motor is directly controlled from the float switches or thru intermediate relays does not much change the logic.

If the high float is made, then the motor is to run no matter how high above the float the water is. Thus, independent of anything else, excluding overload things, when high is made the motor is to run. This means a short across the high limit contacts should force the motor to run. This is a simple test that can be performed at the controller. If shorting the high terminals at the controller does not run the motor, then the problem is in the controller, or something between the controller and the motor.

If the motor runs, or is started and continues to run from shorting the terminals, then look from the terminals back to the high limit float for a problem.

Since this is a pump down application with two float switches we expect once the motor is started that the motor will continue to run until the water level drops below the low float. That means the motor will run, once started, even though the high float is open. To accomplish this we need the low float to parallel the high float switch. But there has to be something in series with the low switch to prevent running the motor from the low switch unless the motor was previously set to on. Thus, a series contact is needed with the low switch that is closed when the motor is running. This can be called a holding contact. A relay that is on when the motor is running can perform this function.

When you are in the pumping down period, and below the high limit, then only the low limit and its series holding contact keeps the motor running.

When the water level drops below the low limit, then the motor stops, and its holding contact opens. Now it is necessary for the water level to reach the high limit before the pump will start again.

Having thought out how this circuit needs to operate, then you can direct your troubleshooting to only those pertinent areas.

.
 
Mustwin351,

I will chime back in now that the traffic has slowed.. I know you was getting bombarded with all kinds of ideas which sometimes can be overwhelming.

Throughout my career I have drawn up more schematics than one would care to hear but it was so helpful when troubleshooting. I would suggest you do the same and take the time to complete the drawing they supplied so your not guessing how it is wired which would be very useful when troubleshooting. I took what information was provided and what I could make out in the pictures you provided (might have missed some details :p) and came up with a circuit that might work with 3 floats and 3 relays. The attached drawing might at least give you some ideas how it might be wired. I will have to go thru all the messages again to see if I missed any info that would refute my drawing. :cool:

I welcome input as to any mistakes one might see.. :eek:hmy:

Hope this helps
 

Attachments

  • Pump.pdf
    4.6 KB · Views: 0
Okay, I already found a mistake.. alarm rung doesn't have an connection to the power rail.. hope nobody is that picky :roll:
 
To OP,


Since you have not provided any schematic of the control board it would be hard to come up with a convincing response that is based on actual installation.

All you can expect is a lot of conjectures, guesses and assumptions.

Here is a generic engineering setup. Depending on the needs of the customer or sophistication of the wiring scheme, this diagram could employ several features. A lot of variance may be employed but the principle stays the same.

In the diagram it uses four gated transistors to drive LEDs. These LEDs could be substituted with a direct load to drive a small solid state relay for instance.

Instead of using simple transistor (SL100) whose gates are triggered by each dedicated probe, you can substitute an IC solid state that could employ an anti-cycling feature to prevent the pump from short cycling. These are all mounted in a PC board. Yes, there is a PC board. This is available online.

You may not think that there's logic circuit because only the ice cubes are visible. If you notice, there is a hockey-pock-looking disc mounted on the side and there is no conventional laminated core transformer on the board itself. This hockey pock is an encapsulated toroidal transformer as opposed to the laminated "E" core old-school transformer. It has small footprint.

This criteria does have in its algorithm. . . the ability that, in case there is an event that will lead to short cycling (dirty probe, liquid turbulence, etc.) it initiates a lock up feature after pump failure .

Pump failure would cause flooding and thereby causing all probes to be submerged. This could also happen during power failure.

The control design engineer (I have designed a few) didn't want the pump to restart automatically after restoration of power. In this type of PC board, a combination electro-mechanical latching relay is required as opposed to all-electric pump motor failure safety feature. (which is probably what you have)

This scheme is evident when you claim that you have to recycle (or reset) power by turning it off and on.

It requires human intervention to prevent further damage especially when control and motor are still submerged in case the motor is non-submersible.

Not ignoring others' inferences, it sounds absurd to think that the system is wired wrong. . .for the simple reason that it was working before.

My comments are based on the graphics you've presented. . . feel free to disambiguate.



http://2.bp.blogspot.com/-464IgyinGWM/ViCQ24xhkbI/AAAAAAAAALM/L5C3t5S4YnU/s1600/water%2Blevel%2Bindicator.png

 
GMc said:
Mustwin351,

I will chime back in now that the traffic has slowed.. I know you was getting bombarded with all kinds of ideas which sometimes can be overwhelming.

Throughout my career I have drawn up more schematics than one would care to hear but it was so helpful when troubleshooting. I would suggest you do the same and take the time to complete the drawing they supplied so your not guessing how it is wired which would be very useful when troubleshooting. I took what information was provided and what I could make out in the pictures you provided (might have missed some details :p) and came up with a circuit that might work with 3 floats and 3 relays. The attached drawing might at least give you some ideas how it might be wired. I will have to go thru all the messages again to see if I missed any info that would refute my drawing. :cool:

I welcome input as to any mistakes one might see.. :eek:hmy:

Hope this helps
Click to expand...

Unless I'm missing something, you don't have a holding contact drawn for the pump to stay running until it pumps down.

In the drawing, as soon as the water level dropped below the top float switch, it would open Relay 2, which would in turn open relay 1 and the motor would stop running without pumping all the way down to the bottom float switch to open it up.

This is just at a quick glance.

If I'm wrong, let me know what's holding Relay 2 in once the water drops below the upper float.

JAP?
 
181015-1704 EDT

GMc:

Yor diagram is post #47 seems very strange.

When hand is selected Relay 1 is energized. This closes R1 to M!, but no power goes to M1 unless R2 is closed, and that won't happen unless you physically close relay 2.

When in Auto AND Top float is closed, then R2 is energized, and in turn R1 is energized, and further in turn M1 runs.

This is not a useful circuit in manual, and has excessive complexity for auto.

.
 
Good catch gar, thanks. In Hand all you would have to do is move the wire to the M1 rung.

As far as the excessive complexity, it's what I came up with using the 3 relays and 3 floats mentioned by the OP. I'm not saying this is how I would do it or how it's actually wired. Just throwing ideas around like everyone else.. :D
 
GMc said:
Good catch gar, thanks. In Hand all you would have to do is move the wire to the M1 rung.

As far as the excessive complexity, it's what I came up with using the 3 relays and 3 floats mentioned by the OP. I'm not saying this is how I would do it or how it's actually wired. Just throwing ideas around like everyone else.. :D
Click to expand...

Yea, I'm sure most of us are questioning the need for 3 relays, but, as it was described, the drawing pretty well nailed it I thought.

JAP>
 
In the posted PDF there is a note about wiring from input of first float switch to output of second float switch if using a pressure control. So I’m thinking floats are in series. This would put the holding circuit across second float switch.

So series connection of FS1 and FS2 pulls in MS and R2. R2 contact establishes holding circuit across FS2. Pump runs until FS1 breaks dropping out R2 and MS. FS3 pulls in R3. R3 contact lights high level lamp. Hand position pulls in R1. R1 contact pulls in MS.

There are many opportunities to improve. No way I’d put floats in series. No way I’d be dead in the water if a single FS failed. Wouldn’t take much to make it operate from FS2 to FS3, or FS1 to FS3, if a float switch failed.
 
Update. So the first pump controller I came across acted up again over the weekend. Same problem...stopped operating in auto. This time I tested voltage to ground across all the float terminals. They all had voltage to ground with the exception of terminal 7 on the start float. Cycling the hoa switch from auto to off and back to auto still produced 0 voltage on terminal 7. Switched it back to off and onto hand (pump ran on hand), back to off and then to auto and like before the relay for auto pulled in which pulled the contactor in and the pump ran. Then I had voltage from terminal 7 to ground.

This pump’s setup is a little more complex but the operation should basically be the same. This time it is a 3 phase pump with a motor starter but looks like the same control board as my other unit (as in the first pictures I posted in my earlier post.)

350D6DBD-0E77-4AD4-8278-28172C75F493.jpg

Thanks for all the input guys.
 
Did you happen to take a voltage reading on terminal 6 during all this ?


Jap>
 
181015-2404 EDT

Mustwin351:

I believe you paid no attention to what I wrote about troubleshooting.

It appears that terminals 6 and 7 are the start float, high level float, and you measured voltage to ground on all terminals except 7 (I have no idea what ground is --- however I assume it is your neutral or common wire, TB 1-3).

What I suggested was that you short 6 and 7 and see if that caused the pump to run. If that short did not cause the motor to run, then the problem is in the controller. If the short caused motor run, then the problem is in the wiring to the float, and/or in the float.

.
 
Status
Not open for further replies.
Top