Power Supply Questions

dougiedigital · Joined: 26 Jun 2016 Posts: 6 Location: United States

Long-time electric brewer (4 years and over 125 brews with it), second-time poster...

Somewhere along the line, my volt meter stopped working. I have no explanation why it stopped working: nothing changed with my configuration, there was no trauma to the panel, and there's no sign of any physical damage or loose connection in the box. But it stopped working, so I ordered a new volt meter from this website.

A couple weeks ago, I installed the new volt meter. Nothing happened. Suspecting that the problem may have been with the power supply that was feeding the volt meter, rather than with the volt meter itself, I went and wired up the volt meter to the same power supply that was already feeding the [working] amp meter. I did this without carefully reading the explanation on this website as to why those meters are fed by different power supplies. Oops. Big mistake. As soon as I powered up the panel, the volt meter blew instantly, sending its faceplate flying through my garage, and leaving my ears ringing for about half an hour. And now the amp meter no longer works, either.

Now smarter and wiser, having read why these meters are fed off different power supplies, I'm trying to pick up the pieces and get both meters working again. I know I need a new amp meter, so I'm going to order one of those. I'm a little unsure if I need a new volt meter, since the old one may have actually been undamaged if it was a different component that was causing it to not work. (The new volt meter was blown to smitherines.) But I'll probably get a new volt meter too, just in case.

My questions:

1) I noticed inside my panel that the red LED light for the bottom power supply (the one feeding the amp meter, which was working before I tried to wire the two meters together) is on. But the red LED light for the top power supply (the one feeding the volt meter) is off. This feels like an obvious question, but should this red LED light be on, signalling that the top power supply indeed was not putting out current? (Somewhat surprisingly, though my mistake of wiring the two meters together seems to have fried the amp meter, this red LED light on the power supply that was feeding the amp meter -- and that was feeding both the amp and volt meters when I wired them together -- still comes on when the control panel is on.)

2) Following this first question... I hooked a meter up to the outputs of the two doorbell transformers, and both of them were reading around 22-23 volts. In conjunction with the observation above about the red LED lights on the power supplies, is this probably a strong indication that the reason the volt meter wasn't working is because the power supply feeding it is broken? If so, any idea what would have caused this? Do these simply go bad over time?

3) The power supplies that came with my panel (purchased around June/July 2014) were adjoined to one another, as shown in the photo below. Presuming I need to replace the power supply that was feeding the volt meter, do you sell power supplies that are similarly joined? I would rather pay a little more money to replace the broken component with an identical one, than to need to drill new holes and/or possibly move things around in the panel a little to accommodate a new power supply that is a different size.

In case it's helpful, here are a couple photographs that depict the power supplies with the panel off, and the power supplies with the panel on (showing the red LED light on for the lower power supply but not the top one). I'm aware that the top power supply does not have any wires attached to its outputs; trust me, the LED light does not come on when those wires are attached, either (whether attached to the amp or to the volt meter).

Thank you much. Please tell me what to buy, and consider it done. Cheers!
doug

**kal** · Posted: Sun Jun 24, 2018 1:24 pm Post subject:

Hi Doug!

I looked up your name to confirm and this is a 50A control panel for 30+ gallons that you purchased as a kit and assembled yourself in 2014.
Some answers for you:

(1) The power supply light should on when the power supply is on.

(2) The power supply powering the voltmeter may indeed no longer be working. Try disconnecting to from the voltmeter and measure the DC voltage coming out of it. You should be able to adjust it to 4.7 to 5.0 V DC.

(3) The power supplies come from the manufacturer in two's, connected together. Normally you would snap them apart before installing. There's no need to keep them attached. If you purchase two you should still receive them attached together like this. Please indicate that you'd like them still attached together when ordering.

Cheers!

Kal

dougiedigital · Joined: 26 Jun 2016 Posts: 6 Location: United States

Thanks a lot, Kal, I really appreciate it.

I disconnected the outputs from the power supply and measured the voltage coming out. It was indeed 5.27 volts coming out of the bottom one (that lights up), and 0 volts coming out of the top (that doesn't). I'm satisfied at this point that the problem indeed was that power supply all along.

I'm placing a new order now for two new power supplies, and I'll be sure to specify that I'd like them to please still stay together. I'll also add an amp meter (to replace the one I blew with my mistake) and a new volt meter, since I blew the new one I ordered, and the previous one still doesn't work even when I connect it to the working power supply. I'm guessing maybe the volt meter AND the power supply went out together.

Cheers!

**kal** · Posted: Sun Jun 24, 2018 9:01 pm Post subject:

dougiedigital · Joined: 26 Jun 2016 Posts: 6 Location: United States

Closing in on this, I hope...

The new components arrived in the mail and I got them all installed. It's safe to say, I think, that the problem before was that the power supply connected to the volt meter went bad. The new power supply lets up as intended, and the new volt meter lights up. It's also safe to say that wiring the volt and amp meters together before did indeed fry the previous amp meter, as the new amp meter plugged in and also works like a charm.

One remaining issue: the volt meter lights up, but reads only "000."

Other than swapping out the power supply, all of the wiring and inputs to the volt meter are unchanged from before, when it was working fine. Just to verify, however, I checked the two "AC" feeds to the volt meter and verified that one of them is going to the designated post on the boil relay, and the other is wired to the hot bus.

Any ideas what could be going on here? Thanks in advance, I'm hopeful that the finish line is near on this issue!

**kal** · Posted: Tue Jul 03, 2018 2:19 am Post subject:

dougiedigital · Joined: 26 Jun 2016 Posts: 6 Location: United States

Thanks, Kal.

Unfortunately, it looks like I spoke too soon. I left the panel on overnight, just idle, and when I came down this morning I saw that the volt meter was out again (instead of displaying "000" as it was through the evening and when I went to bed). Opened the panel, and the red LED light on the new power supply (the one feeding the volt meter) is again off.

This is essentially how the panel was ~3 weeks ago when I took on this project of trying to fix it: a volt meter that didn't light up, and a corresponding power supply with the red LED off. The only difference is that now both the volt meter and the power supply have been replaced (along with an additional volt meter and amp meter that I burned through when I cross-wired them while trying to fix this). In other words, ~3 weeks and $61 later, and I'm right back to where I started, with really no better understanding as to what's going on. And I'm wary of going poking around in there with a voltmeter while the panel is on because every other time I try that I get zapped (yesterday's zap happened without me even touching anything, while I was on my way in to check the voltage out on one of the power supplies).

Pretty frustrated with this, to be honest. I can use a voltmeter to check the connection points from the hot bus and from the boil relay to the voltmeter, while the panel is off, to at least make sure that the connections are proper and the wire is intact. An issue there would explain why the voltmeter was reading 000. But would this also explain why this power supply has gone out, twice now, while the unit is just sitting there idle? If not, what else could be causing that? What's especially baffling to me about the whole thing is that it was working fine for quite a while, and then just simply stopped, without any evident change to anything in the panel or any sort of event happening to it.

**kal** · Posted: Tue Jul 03, 2018 10:53 pm Post subject:

My guess is that something in the panel you've assembled has possibly come loose / is shorting out intermittently somewhere.

Are you using the nylon standoffs we supply with our power supplies or still using the rubber spacers with metal bolts you used in your original build (based on the pictures you posted). If I was a betting man, I bet that over time your rubber spacers have gotten compressed and/or are getting compressed and you're shorting your power supplies against the backplane. The metal bolts can also sometimes cause issues if they're not sitting exactly right.

We now only supply nylon bolts and standoffs with our power supplies to help avoid any shorting issues.

Kal