reef-pi :: An opensource reef tank controller based on Raspberry Pi.

theatrus

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Most project boxes are not UL Certified for electrical use. I have taken apart items such as x-box and other items and there is Almost always a Metal shield around or under components that have high heat or large capacitors . I am not really the right person to ask what is considered safe. I just know how i do things based on how i have seen Actual Electricians have done so and how things seem to be made.

Metal enclosures like this are almost always for EMI / radiated emissions. Everything becomes a radio transmitter, so these are the attenuation mechanisms.

Most plastics designed for electronics should be rated as UL 94V0, which is filled with enough flame retardant materials to not keep a flame for more than 10 seconds.

https://en.m.wikipedia.org/wiki/UL_94

My concern with is light build is all of those open Power units .I have seen them after a short. If there were one or two and spaced way apart i would probably not have even commented..

Maybe Just reminding people to be aware of safety and Recommend ul approved or Metal box or metal shielding under or behind power components Where high AC Voltage is connected to step down converters or when many Voltage converters are in play together.. I think Lights and Relays are the two things of Concern with our builds . the ADJ Solves one of them for those that can go that rout .For me the Outlets have to be spaced out. I can ask Drew to do a small write up for us about electrical safety that applies to our designs...

I agree - don’t mess with high power lightly. There are a number of factors to consider (clearance, current, wire sizing, fusing, etc).
 

Dave's Reef

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What image should I follow for my float switch that will run my mixing station and RO/DI tank solenoid.

reef-pi_ATO_schem.jpg


upload_2018-2-17_18-23-7.png
 

Kampo

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trying to mess arround with this again ahead of my new build doing a simple 2 channel test light, and using the GPIO 18/19 for pwm. I get massive flickering at anything but 100% its almost like its pulsing the PWM super slow so its visable to my eye. is there a setting I missed?
 

LionHeart2017

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So, the original enclosure was using edge mounts then.
the original was a clipped together plastic housing with 2 small vent holes near heatsinks, the circuit board was just placed on the bottom housing part on plastic locating pins, thinking on version 3 and mains safety next, but for now I need lights on and in the version 3 I think I will run the relay and the 8 drivers together but remove the pi, the 5v supply, the 12v supply to its own little housing close by, this way I will get more room and more robust mains electrical connections into the box
 

theatrus

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What image should I follow for my float switch that will run my mixing station and RO/DI tank solenoid.

Always use the 3.3V line, not the 5V. Raspberry GPIOs are only 3.3V. With that fix...

First (with 220ohm resistor) is preferred.

Why?

If you end up in a state where the switch is closed and the sensor is configured as an output, you can short the supply voltage through the GPIO pin which will be destructive. The resistor will limit it. It will still be 15ma so on the high end but not unreasonable for short durations.
 

Dave's Reef

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Always use the 3.3V line, not the 5V. Raspberry GPIOs are only 3.3V. With that fix...

First (with 220ohm resistor) is preferred.

Why?

If you end up in a state where the switch is closed and the sensor is configured as an output, you can short the supply voltage through the GPIO pin which will be destructive. The resistor will limit it. It will still be 15ma so on the high end but not unreasonable for short durations.

Thank you that is what I will do.
 

ScottBrew

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the original was a clipped together plastic housing with 2 small vent holes near heatsinks, the circuit board was just placed on the bottom housing part on plastic locating pins, thinking on version 3 and mains safety next, but for now I need lights on and in the version 3 I think I will run the relay and the 8 drivers together but remove the pi, the 5v supply, the 12v supply to its own little housing close by, this way I will get more room and more robust mains electrical connections into the box
Just throwing this idea out. How about standing the boards up on their end atop an aluminum plate with the heatsinks against the plate with heatsink compound? Then just contain the boards at the bottom corners with a strip of plastic with notches and one at the top center with notches as well.
 

ScottBrew

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the original was a clipped together plastic housing with 2 small vent holes near heatsinks, the circuit board was just placed on the bottom housing part on plastic locating pins, thinking on version 3 and mains safety next, but for now I need lights on and in the version 3 I think I will run the relay and the 8 drivers together but remove the pi, the 5v supply, the 12v supply to its own little housing close by, this way I will get more room and more robust mains electrical connections into the box

Something like this...
IMG_20181111_144248.jpg
 

LionHeart2017

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Thanks ScottBrew, standing on their sides might be possible if I can fix a badly aligned heatsink on one of the drivers, I also thought about a couple of nice new driver that could power all 4 channels of blue from 1 unit and 1 for the white channels, I'm just not sure how I go about it as I'd want pwm and be able to run 4 panels from a single driver, not even sure if possible
 
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Metal enclosures like this are almost always for EMI / radiated emissions. Everything becomes a radio transmitter, so these are the attenuation mechanisms.

Most plastics designed for electronics should be rated as UL 94V0, which is filled with enough flame retardant materials to not keep a flame for more than 10 seconds.

https://en.m.wikipedia.org/wiki/UL_94



I agree - don’t mess with high power lightly. There are a number of factors to consider (clearance, current, wire sizing, fusing, etc).
Very informative. Thank you for sharing this, I'll add some of the key information here in the official docs
 
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Ranjib

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trying to mess arround with this again ahead of my new build doing a simple 2 channel test light, and using the GPIO 18/19 for pwm. I get massive flickering at anything but 100% its almost like its pulsing the PWM super slow so its visable to my eye. is there a setting I missed?
If you navigate to Configuration -> Settings section, theres a place to adjust the PWM frequency for rpi. You have to play with it, start with 10, and then try 50, 100, 200, 500, 1000 etc.You have to reload reef-pi everytime you update the PWM frequency, and some time reboot it (rarely). Take a look ate the logs when you do this, and if you see error, then only do the reboot, else just reload is all you need. I hit the same issue, but adjusting the PWM frequency solved every single of those. Keep us posted
 
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Ranjib

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the original was a clipped together plastic housing with 2 small vent holes near heatsinks, the circuit board was just placed on the bottom housing part on plastic locating pins, thinking on version 3 and mains safety next, but for now I need lights on and in the version 3 I think I will run the relay and the 8 drivers together but remove the pi, the 5v supply, the 12v supply to its own little housing close by, this way I will get more room and more robust mains electrical connections into the box
Yes, I too found that isolating the high power (AC110V) and low power (DC 12V) components in separate housing solved lot of my headaches. And I was not reaping whole lot of benefits by keeping them together
 
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Ranjib

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Thank you that is what I will do.
Just of followup advice here for you and others, @theatrus is way more knowledgeable than me when it comes to electronics. You and rest of us can count on his advice and I'll personally take his advice in case of any conflict/arbitration.
@Roberto_b and @Michael Lane also have a significantly better grasp on electronics than most of us. The community is fortunate to have these great folks among us :)
 
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Hello, fell0w reefers
Its that time again, I have cut a new release candidate of reef-pi, rc3. Its exclusively a bug fix release. Following are the highlights:

Features
  • Allow editing light names
  • Allow fine grain pwm values (percentages can be float instead of int)
Bugfixes
  • Fix PWM value computation for diurnal cycle
  • Superfluous error dialogs in telemetry configuration UI
  • Superfluous error dialogs during reload
  • Superfluous error dialogs during initial setup of components
  • Footer information appearing over other UI components
With this release, I am not aware of any more outstanding bugs, which means this is likely the final 2.0 release. Unless we encounter any more bugs rc3 will be re-published as reef-pi 2.0 public release. Which is pretty exciting :0)
release builds can be found in the usual location: https://github.com/reef-pi/reef-pi/releases/tag/2.0.0-rc3

Thanks to @Michael Lane for some of the UI fixes, and @Erica-Renee for testing rc2 and calling out few UI hiccups. You all are awesome.
 

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