Can I run my EB8 at 24V DC?

[karimwassef]

I understand that there is a conversion between AC and DC inside each EB8 so that it can function independently in case the communication logic between it and the controller is broken, but other than that, I assume the internal relays can operate just as well on DC as AC?

Here's my dilemna. I want to add battery backup to my existing DC pumps and powerheads that run at 24VDC.

I can do this, but a single battery backup system can handle up to 8 of my pumps at a time.

I'm willing to partition out a dedicated EB8 to these pumps, but I want them all to share the battery backup, so the input to the EB8 would need to be DC, not AC. In case the power goes out, The pumps would continue to operate off the DC input to the EB8.

By the way, I run a UPS on my Apex now, so my controller and all the EB8s stay up during a power outtage. The problem is that the power to the outlets goes away. I have one dedicated pump running directly off the UPS, but it will only last for an hour. The conversion from battery DC to AC, then AC to DC is very wasteful when all I need is 24VDC.

I hope there's an elegant solution here. And I hope that Neptune seriously considers a DC input/output EB8 going forward (able to accomodate 12V or 24V).

 

[RussM]

No you cannot.

 

[karimwassef]

Ok. Other than voiding the warranty, what would happen if someone did?

I'm wondering about potential damage or danger.

 

[RussM]

It simply won't work. Among various reasons, the TRIAC (solid state switches, not mechanical relays) used for 6 of the 8 outlets only switch AC.

 

[karimwassef]

ok. so the only path forward is to make my own box with relays and use a signal from the Apex VDM module to turn them on and off.

It's a waste really since I just need 8 signals at on/off but all i can get is 4 analog setpoints between 1-10V. But it's $100 instead of the $150 for the EB8.

Maybe the new 1LINK, but that only does three 24VDC pumps at a time and are $150 too.

 

[karimwassef]

Maybe I'll use the VDM and then use a binary scheme to control multiple relays from each of the four V outputs.

I could do 2 out of each, so one VDM works. Or I can do 4 each, so that'll give me two more free V outlets to use. That makes it really complicated from the point of virtual modules that are needed and the coding at the VDM outputs themselves.

 

[karimwassef]

so I could do this...

<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zpscjzjla06.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zpscjzjla06.png" border="0" alt=" photo 0_zpscjzjla06.png"/></a>

and maybe use the inter digital space to make other adjustments...

so for example, 0V is all off, 3.33V is output 1 is on, output 2 is off. But I can use the 0.1V to 3.1V space t make other adjustments with outlet setting reference to the 0V condition.

Complicated, but I don't see other options.

I could go to 4 per V:

<a href="http://s1062.photobucket.com/user/karimwassef/media/1_zpsz2oqt7py.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/1_zpsz2oqt7py.png" border="0" alt=" photo 1_zpsz2oqt7py.png"/></a>

so much work for something Neptune could have made so easy.

 

[karimwassef]

Russ - can you find a better way of doing it?

 

[karimwassef]

anyone?

 

[figuerres]

anyone?

Kind of sounds like you want something like the Tunze safety battery setup, check on how Tunze pumps are 24vdc and they have a connector to draw from a battery when main power is lost.

Also Neptune systems has a power supply thing to know when ac power is lost so that you can program for that happening.

Combine the two ideas....

 

[karimwassef]

I have a UPS and a power adapter for my Apex already.

What I need is a 24VDC EB8... no such thing, so I'll have to make one up. I wish they'd sell the heart of the EB8 without the outlets... just 8 on/off signal outputs module.

 

[figuerres]

I have a UPS and a power adapter for my Apex already.

What I need is a 24VDC EB8... no such thing, so I'll have to make one up. I wish they'd sell the heart of the EB8 without the outlets... just 8 on/off signal outputs module.

well I will look at this from the side of the makers for a minute:


every device comes with an ac power supply. not all devices use 24 vdc.
some draw more power than others. a lot of stuff is 5 volt,9 volt, 10 and 12 volt as well as 24 volt, some are ac not dc.
the simple answer is to build for the one standard that will work for all of the above.

that is why I think they are not making the item.

just saying....

 

[aaronpentz]

There is a way to do what you want with additional equipment. You would purchase a 110vac coil relay and wire the 24vdc on the contacts. Have the Apex keep the relay energized. When you lose power the relay will de-energize and the battery will kick in. I can draw something up if you want but you should have an electrician help you out if you're not comfortable working with ac voltage

One required for each pump. URL: http://pages.ebay.com/link/?nav=item.view&id=331326301626&alt=web

 

[karimwassef]

Thanks. I think I get it. It's basically using the EB8 outlets as control signals to switch the AC coil relays on and off. The relays conduct the 24VDC to the pump.

I thought of that but the battery backup daisy chains which made me think that there is some logic between the power connected to each pump.

Having said that, my original idea of a 24VDC input would have the same issue. Either I can run the pumps in parallel off the 24VDC bus or I can't... So I'm not sure why I didn't follow it.

Thanks for simplifying things. I'll probably go with these relays since they're rated to 10A at 28VDC which should top out my neediest pump at ~200W full power.

https://www.amazon.com/gp/aw/d/B00E...0v+10A+28V&dpPl=1&dpID=4108iOL37oL&ref=plSrch

Still wish I didn't have to buy a $150 EB8 to get 8 on/off signals out of my Apex.

I agree that voltages could be anything... 5V, 12V, 24V, 48V so AC is the safest popular option, but just like the VDM modules create 4 analog 0-10V signal outputs, a VNF (I made that up for Variable oN ofF. ) with 8 digital on/off signals would rock (and be much cheaper to build and sell).

 

[aaronpentz]

You only need one outlet from an eb8 but there wouldn't be any controlling the pumps via the controller. And to do maintenance you would have to shut down the 24vdc line and then unplug the pump. Unless you added some disconnect switches which would be easy to do now. You could also use a 5vdc coil relay and use one variable port if you didn't want to buy another eb8. Do you need all 8 pumps running when the powers out


All they would have to do is make a dry contact version of the eb8 and that would solve your problems. Then you could use whatever voltages you needed inside the specs of the relay on the board. But I'm sure there are liabilities involved with that as not everybody knows how to wire stuff properly and I'm sure Neptune doesn't want to be responsible for burning someone's house down or worse. All because they made and sold something to someone who had no clue what's going on. So I understand.

 

[karimwassef]

The pump controllers all have an 'off' button in their feed mode. So cutting power and then disconnecting the cable is not an issue.

I don't need all 8 but I do need two or three and don't want to but multiple batteries when each can run multiples.

 

[aaronpentz]

Can you just run the pumps on the batteries full time and then just upgrade the charging circuit to accommodate the extra load. Then you don't need any switching gear and the trouble it can cause

Or just switch the load at the battery. I run all my vortechs and my two dc return pumps from one larger industrial switching power supply. You could do the same and then only have to worry about the one feed. Then you could just use one relay with the coil plugged directly into the wall not the eb8. When you lose main power it would automatically switch to battery power and then auto switch back to main power when it is restored

 

[karimwassef]

The battery pack runs pass through power when AC is available. It just switches to battery if the AC goes out and the pump load is still connected. It has an internal switch.

 

[aaronpentz]

If it outputs 24vdc then even better. Just power any pump you want running when main power goes out from that and not the power brick that came with the pump

 

[karimwassef]

Exactly.