POWER PLANT BUILD THREAD

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Jonk
Posts: 9
Joined: Thu Oct 01, 2009 2:50 am

Re: POWER PLANT BUILD THREAD

Post by Jonk »

Hi,

I have a power plant here that was blowing fuses (unloaded so I know it's the power plant) I replaced the 110/220 switch and it stopped blowing fuses but I couldn't adjust the regulators for 24 and 48V's They only go up to 17VDC and 35VDC respectively. I tried replacing the regulators to see if they were the problem but no change. And the power transformer is getting very hot.

Any ideas what's going on here?

Jonk
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Joined: Thu Oct 01, 2009 2:50 am

Re: POWER PLANT BUILD THREAD

Post by Jonk »

This can't be right. I have 51VAC, 54VAC, 56VAC, 62VAC on the power transformer secondaries. ??? Maybe I hard wired the pirmaries wrong. Okay, it's a DPDT slide switch so I hardwired the side that says 110V. I don't get it. . .

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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

Jonk wrote:
Mon Sep 06, 2021 5:39 am
This can't be right. I have 51VAC, 54VAC, 56VAC, 62VAC on the power transformer secondaries. ??? Maybe I hard wired the pirmaries wrong. Okay, it's a DPDT slide switch so I hardwired the side that says 110V. I don't get it. . .
The 115v / 230v switch overlay shows the correct way to fit the switch which should be fitted but if you do not fit the switch since it is a slide switch that shows the voltage when slide the opposite way you would have to jumper the opposite side to the voltage written on the pcb. But I cannot see how either way you could get that winding voltage unless something is built wrong. Remove the 2 silicon tubes and send me some top and bottom photos of your kit build so I can check it over.
Joe :-)
JLM Audio
Capturing Audio without Injury

Jonk
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Re: POWER PLANT BUILD THREAD

Post by Jonk »

Thanks Joe,

Here's some pics. This was a successful build, calibrated correctly and powering four Neve 1290 cards for about 6 months. Then one day I powered it on and the fuse blew.

So I suspected that slide switch.

So, if I get you right, the correct pads to jumper for 115V would actually be on the 230V side, according to the pcb. Interesting. So I was getting the voltages on the secondaries mentioned in the earlier post while accidentally connecting the primaries for 230V. Now connecting the primaries correctly I'm back to blowing fuses again upon power up.
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Joe Malone
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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

Jonk wrote:
Tue Sep 07, 2021 2:29 am
Thanks Joe,

Here's some pics. This was a successful build, calibrated correctly and powering four Neve 1290 cards for about 6 months. Then one day I powered it on and the fuse blew.

So I suspected that slide switch.

So, if I get you right, the correct pads to jumper for 115V would actually be on the 230V side, according to the pcb. Interesting. So I was getting the voltages on the secondaries mentioned in the earlier post while accidentally connecting the primaries for 230V. Now connecting the primaries correctly I'm back to blowing fuses again upon power up.
Sounds like a dead short on one primary winding. Remove power and remove the 2 110v jumper wires and check the ohms on each 115v primary winding which should be about 80ohms each from memory. Check there is no solder short under the pcb at the high volts end. let me know what you find.

If the ac volts on the secondary was actually the volts you mention the 1000uF caps would all have blown their tops.
Joe :-)
JLM Audio
Capturing Audio without Injury

Jonk
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Re: POWER PLANT BUILD THREAD

Post by Jonk »

Okay,

back with some ohm readings. Sounds like you're right (I think?) One primary reads 16ohm. The other is 91ohm.

Jonk
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Re: POWER PLANT BUILD THREAD

Post by Jonk »

So, what would you expect to need to be replaced besides the power transformer? Caps as well? Not seeing them puffing out though.

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Joe Malone
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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

Jonk wrote:
Thu Sep 09, 2021 5:57 am
So, what would you expect to need to be replaced besides the power transformer? Caps as well? Not seeing them puffing out though.
HI Jonk
It should only need a new transformer as the caps look fine. Email me to so i can quote price for one with shipping for you.
Joe :-)
JLM Audio
Capturing Audio without Injury

claussoegaard
Posts: 2
Joined: Sun Apr 16, 2023 11:02 pm

Re: POWER PLANT BUILD THREAD

Post by claussoegaard »

Hi! Just received (and built) a Power Plant 2. Super easy assembly, good instructions, and after trimming the regulators I'm getting a beautiful steady spot on 24/48v on the outputs. Beautiful.

I plan to install this into an external enclosure to lower risk of noise/hum in whatever gear I end up powering up with this. I bought a few Hammond and other boxes that I think will fit, so I have some options for which I like the most. Once I am completely finished I will post pics from the full build, if that's a useful thing to do.

My question: I have never used 4-pin XLRs before, which is what I plan to use for the power out. Obviously I can just wire it up however so it works, but I am curious if there are any best practices for this type of power cable wiring? I can't seem to find any resources online for this. Here's what I'm thinking.

Pin 1: 0v
Pin 2: 24v
Pin 3: 48v
Pin 4: Chassis ground
G: Also chassis ground (bridged to pin 4)

Does this make sense? Any problems here? Should I not hook up chassis ground at all? Should I not bridge the shield/sleeve of the connector to a pin, like I was thinking with pin 4/G?

Would love some feedback.

Thanks again!
Cheers

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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

claussoegaard wrote:
Mon Apr 17, 2023 5:33 pm
Hi! Just received (and built) a Power Plant 2. Super easy assembly, good instructions, and after trimming the regulators I'm getting a beautiful steady spot on 24/48v on the outputs. Beautiful.

I plan to install this into an external enclosure to lower risk of noise/hum in whatever gear I end up powering up with this. I bought a few Hammond and other boxes that I think will fit, so I have some options for which I like the most. Once I am completely finished I will post pics from the full build, if that's a useful thing to do.

My question: I have never used 4-pin XLRs before, which is what I plan to use for the power out. Obviously I can just wire it up however so it works, but I am curious if there are any best practices for this type of power cable wiring? I can't seem to find any resources online for this. Here's what I'm thinking.

Pin 1: 0v
Pin 2: 24v
Pin 3: 48v
Pin 4: Chassis ground
G: Also chassis ground (bridged to pin 4)

Does this make sense? Any problems here? Should I not hook up chassis ground at all? Should I not bridge the shield/sleeve of the connector to a pin, like I was thinking with pin 4/G?

Would love some feedback.

Thanks again!
Cheers
I don’t know of any standards for 4 pin XLR’s but usually always pin 1 chassis / ground like audio XLR. A lot of female 3,4,5 XLR pin 1 are raised to make contact first.

API 5 pin power
Pin 1 chassis
Pin 2 GND 0v
Pin 3 +16v
Pin 4 -16v
Pin 5 48v

JLM TMP8 48v power
Pin 1 0v
Pin 5 48v
Joe :-)
JLM Audio
Capturing Audio without Injury

claussoegaard
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Joined: Sun Apr 16, 2023 11:02 pm

Re: POWER PLANT BUILD THREAD

Post by claussoegaard »

Awesome, thanks Joe.

Based on that I think I will do:

Pin 1: Chassis
Pin 2: 0v
Pin 3: 24v
Pin 4: 48v

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Joe Malone
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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

claussoegaard wrote:
Mon Apr 17, 2023 6:36 pm
Awesome, thanks Joe.

Based on that I think I will do:

Pin 1: Chassis
Pin 2: 0v
Pin 3: 24v
Pin 4: 48v
Seems like a plan.

I always use 5 pin for power if multiple rails so I have power pins in the same place encase a power supply is swapped. A +V being a few volts higher or lower is usually not a problem but -v and +v swapping is bad :-)

My powerplant wiring so it matches my 500 rack power supplies.
Pin 1: Chassis
Pin 2: 0v
Pin 3: +V
Pin 4: -V (not used)
Pin 5: +48v
Joe :-)
JLM Audio
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RelevantOctopus
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Joined: Tue Jan 23, 2024 6:51 am

Re: POWER PLANT BUILD THREAD

Post by RelevantOctopus »

Hi Everyone,
Hope this is posted properly, if not please don't hesitate to correct me.

I am having trouble with a couple Power Plants and I am hoping someone with more experience in electrical theory can point me in the right direction.

PP 1:
Had been working absolutely perfectly, powering 2 Telefunken V376 preamps for a long enough time to tell that it wasn't mis-wired and my building/soldering skills are fine.
Then one day it blew up, literally, with a loud bang, smoke and giant spike thru the monitors.
The 24v rail is fine and functioning perfectly still, but the 48v rail's LM317 was in pieces, one 10uf cap had blown the can right off and sprayed the the other components with a hairy looking substance of some sort, and one 120R resistor was charcoal. So I replaced all the visibly damaged components. Now I have only ~2.8v on the 48v rail. Obviously something else is damaged but I don't know what to look for. Internet research has proven fruitless.

PP 2:
Has never been in service, but has been built and tested and works fine, except for the only ~35v on the 48v rail issue.

I can find a schematic, but I can't find a schematic with voltages ('test points' if you will) and I am in no way an electrical engineer, so I am at a loss as what to do to figure out why these issues are plaguing me.

The kits are great, I must be doing something silly.
If anyone can help, I would really appreciate it.

RelevantOctopus
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Joined: Tue Jan 23, 2024 6:51 am

Re: POWER PLANT BUILD THREAD

Post by RelevantOctopus »

Hmmm yes, Please disregard the PP 2 questions. Someone wasn't turning the trimpot far enough. Voltages are fine and rock solid.
However PP 1 is not working correctly still. Could use any pointers anyone may have.
Thanks!

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Re: POWER PLANT BUILD THREAD

Post by Joe Malone »

RelevantOctopus wrote:
Sat Apr 27, 2024 11:53 pm
Hmmm yes, Please disregard the PP 2 questions. Someone wasn't turning the trimpot far enough. Voltages are fine and rock solid.
However PP 1 is not working correctly still. Could use any pointers anyone may have.
Thanks!
Hi I have replied to all your email from our normal and gmail account and sent you a text message as your email bounces back all the time
I mounted it in a separate box, and added pilot lights (green LEDs for 24V and 48V - the 24V green LED indicator and power rail is fine).

I powered the 48V rail green LED indicator's anode from the 48V out of the power supply, thru a 2K4 resistor and connected the LED's cathode to 0V directly.
[Joe] Ok modern leds running 20mA is way to high. The 2k4 will be making 1W of heat so would need to be a 5W ceramic type. It would have probably unsoldered itself from the heat. You shouldn't need lower than 10k to 20k.
Even better use high brightness type with 100k 1/4w resistor so none of the 48v output current is wasted on running a led
This was working fine for hours on end. I went to use it yesterday and after a few minutes I got a loud BANG and a giant spike thru my monitors (didn't hurt them. Dynaudio you know). So I turned it off right away and took it apart to find that the resistor on the cathode leading back to 48V had somehow disconnected itself and the 48V LM317 and one of the 10mf 63V caps had literally exploded.
[Joe] This suggests a sudden dead short on the output while powered up and running
Would the resistor detaching itself (obviously bad soldering on my part, which is HIGHLY unusual) cause the explosions? Should I NOT have a pilot light in the circuit or did I implement it incorrectly? Or should I suspect something else? As I said, it worked great for quite a while, the only thing I could see different was the detached resistor. Please let me know what you think about this.
[Joe] See above answers. But you should be able to replace the LM317 and 10uF and the rail if everything else is ok should power up to 48v again without touching the trimpot again. Do not turn the trimpot down as this could blow the new regulator. I cannot remember if this was a kit or built by us? If a kit best to send me a couple of top and bottom photos to check the build and wiring over.
Joe :-)
JLM Audio
Capturing Audio without Injury

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