Anyone Have Trouble Controlling Pumps with Relays?

[gbru316]

As in back flow? No - and that was a concern also. However, I did not ever read on these pumps to protect against it. All these “wonders” make me wonder if this is truly why their battery backup system is pushed? Is it really for tank protection - or pump protection?

correct. A relay is essentially a big inductor. When you turn it off, there will be a voltage spike as the magnetic field tries to sustain output (and this can be in the hundreds of volts for a very brief period of time).

Any time I use relays in test set design, I include a fly back diode to suppress it.

Sometimes relays have this built-in. Check the data sheet. If it doesn’t, and If you’re up for a science fair project, you could put a scope on the +24 Vdc output of the vectra power supply and check for transients as you cycle the relay. It’d probably require you to cut some wire insulation as you’d need to do it under load, but it would be a interesting project.


Keep in mind that these are consumer products. The level of design verification testing and reliability analysis is probably not on-par with industrial products.

 

[JDCagley]

correct. A relay is essentially a big inductor. When you turn it off, there will be a voltage spike as the magnetic field tries to sustain output (and this can be in the hundreds of volts for a very brief period of time).

Any time I use relays in test set design, I include a fly back diode to suppress it.

Sometimes relays have this built-in. Check the data sheet. If it doesn’t, and If you’re up for a science fair project, you could put a scope on the +24 Vdc output of the vectra power supply and check for transients as you cycle the relay. It’d probably require you to cut some wire insulation as you’d need to do it under load, but it would be a interesting project.


Keep in mind that these are consumer products. The level of design verification testing and reliability analysis is probably not on-par with industrial products

The relays are RIB by Functional Devices - all rib relays have transient voltage protection built in. Thanks for the reply.

 

[JDCagley]

The relays are RIB by Functional Devices - all rib relays have transient voltage protection built in. Thanks for the reply.

I thought you meant water side back flow

 

[JDCagley]

I don't do the electrical design of our systems and digging through all the data sheets for which products we use. I am a software engineer. I used to be an electrician (almost 20 years) - but even then, I didn't get into the "weeds" of design - I was "just" a journeyman installer of someone else's design.

 

[JDCagley]

If only this industry could find the light.

I am not holding my breath though, and EcoTech as a brand hasn't played very nice with other companies customers be danged. EcoTech used to integrate well with Apex but the big egos came out and that is why we can't have nice things.

Not sure if your Vectra is plumbed in or out but either way there are solid AC alternatives, and truth be told I am tired of the useless invoation for the sake of their bottom line. It really doesn't help me but it sure does help their profit margins. I have been going back to some of the old school solutions and I am surprised to see that many still exist. For external plumbs Iwaki is hands down the best most reliable AC pump and you can turn it on and off to your hearts desire.

I really liked the idea of DC control when I got back into this hobby (left due to a nasty divorce in 2013). Quiet, controllable flow rates, etc. all sound great until you realize they have it locked out. I want to send my own 0-10 signal to control speed - would make life so much easier. I have actually considered looking at taking one of these apart to find out exactly how their speed modulation works - I am betting 0-10VDC. That is pretty typical, common and cost effective. The issue here is cost of the pump and wanting to "play" with it. I could also possibly see it being PWM, but again, that is native to the control world I live in and easily "sent". Oh well....

 

[SteveMM62Reef]

At work we had Energy Management Cabinets, using 0 - 10 Vdc. All the switching was done on the DC Side, not AC Coming in. There were Wired Capacitors on the DC side, and Choke Coils. Also on the AC Side were Wired in Surge Suppression with Neutral and Hot Side Protection.