Terminal Block Usage

[GParkins]

Building on your last, which is safer, a properly grounded metal enclosure or a plastic one? Or any reasons to prefer one over the other?

Both can be safe, and depending on the application, there are times that non-metallic (NM) enclosures are preferred.

Reasons to use metallic:

1) You need more strength than a comparable NM enclosure offers.
2) The equipment inside the enclosure runs at a high temperature
3) Available NM enclosures aren't big enough.

Reasons to use NM:

1) Corrosive environment
2) Weight reduction
3) Ease of fabrication

As long as the enclosure meets codes and standards, it should be OK in a brewery. It may be an area where another opinion is helpful. Also, you should try to get as close to IP65 as is practical. You don't want the spray from a burst hose able to get into the enclosure.

 

[ancientmariner52]

Thanks. I used a rain-tight Bud Industries plastic enclosure, mainly for the lighter weight and price. And I even like the color.

 

[GParkins]

a rain-tight Bud Industries plastic enclosure

What's the model number?

 

[ancientmariner52]

No idea, I seem to have used a four inch hole saw where the id markings were. It's about 12" x 16" x 7", with snap latches, a gasketed lid, a pleasant light beige.

I cut a hole in the bottom to mount a cooling fan, and another in the back for air exhaust. Obviously no longer spray proof, and I locate it accordingly. I use a modular shelf on wheels to store and move my gear, and I hang the enclosure on one of the shelves for use. I brew near my house's earth ground, I suppose a jumper cable from ground rod to the shelf might be wise.

 

[ancientmariner52]

Found it.

BUD Industries NBF-32026 ABS Economy Box

IP66 of IEC529
NEMA 1, 2, 4, 4x

Doesn't say outdoor, so I probably got that wrong. I saw plastic enclosures being used throughout the gardens at Crystal Bridges, so I looked for outdoor enclosures on Amazon and this showed up.

 

[itsnotrequired]

nema 4 is rated for spray-directed water (i.e. a hose). it will work outdoors as well as indoors.

the 'x' means it is rated for corrosive environments (e.g marine/salts, petrochem, etc.) the boxes are either plastic, fiberglass or stainless steel.

 

[ancientmariner52]

Thanks. I'm learning so much here.

 

[GParkins]

Doesn't say outdoor, so I probably got that wrong. I saw plastic enclosures being used throughout the gardens at Crystal Bridges, so I looked for outdoor enclosures on Amazon and this showed up.

Since you've cut the ventilation holes, worrying about any kind of moisture protection is kinda moot at this point. Most of the rest of the box seems OK. The only thing that I would have to change before I could use it where I work is the addition of some kind of additional locking mechanism for the lid that would then require tools to access the inside of the enclosure.

 

[ancientmariner52]

Yes, I understand about moisture protection going away when I saw great honkin' holes in the box. The lid and box have tabs for a small padlock or tamper seal, but that really wasn't a concern in my back yard. Thanks for the info.

 

[BrunDog]

Regarding the terminal blocks, my biggest struggle was finding terminal blocks/bus for low voltage power and ground. Having ~14 devices (sensors, valves, etc.) means lots of these. But I don’t have the space to afford a whole row of din rail TB’s. Anyone know any super space efficient units that are reasonable and easily sourced? I know wago, weidmuller, and Phoenix Contact have these, but the catalogs are a nightmare and they are not easily sourced.

 

[Tartan1]

I'm using these for my DC devices, I like the fact each device can be individually protected. More compact than a row(s) of terminal blocks however I wouldn't say they are super space savers though .

https://www.ebay.ca/itm/DIN-Rail-Mo...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[BrunDog]

Very sweet! You are right - not exactly space saver but very proper protection!

 

[BeardedBrews]

Regarding the terminal blocks, my biggest struggle was finding terminal blocks/bus for low voltage power and ground. Having ~14 devices (sensors, valves, etc.) means lots of these. But I don’t have the space to afford a whole row of din rail TB’s. Anyone know any super space efficient units that are reasonable and easily sourced? I know wago, weidmuller, and Phoenix Contact have these, but the catalogs are a nightmare and they are not easily sourced.

Something fancier than a mini busbar?

https://www.bluesea.com/products/2105/MaxiBus_250A_BusBar_-_Two_5_16in-18_Studs_and_Twelve_#10-24_Screws

Edit; and presumably classier than epoxying a m8 bolt inside the box and wing-nutting all the crimped rings on top

 

[BrunDog]

Yes. And oh gosh yes!

Looking for a DIN rail solution. Something high density. I did see some triple stacking Phoenix terminals - they would work well for small gauge DC connections.

 

[BeardedBrews]

Yes. And oh gosh yes!

Looking for a DIN rail solution. Something high density. I did see some triple stacking Phoenix terminals - they would work well for small gauge DC connections.

I can't say I've seen something on a din bar that's narrower than this :

https://www.asi-ez.com/pix/doc/powerdistribution_busbars_datasheet.pdf#view=fitv

But there must be something out there for lawn sprinkler control boxes

 

[BeardedBrews]

You could build your own version of this : https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/271571120367

Using these : https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/171758278263

And a soldered solid connector behind the board...

 

[GParkins]

Regarding the terminal blocks, my biggest struggle was finding terminal blocks/bus for low voltage power and ground. Having ~14 devices (sensors, valves, etc.) means lots of these. But I don’t have the space to afford a whole row of din rail TB’s. Anyone know any super space efficient units that are reasonable and easily sourced? I know wago, weidmuller, and Phoenix Contact have these, but the catalogs are a nightmare and they are not easily sourced.

DIN rail mount, or nah?

 

[Brickman]

I used Dinkle connectors for my panel build. They are the same ones that Auber sells in their DIN connector kit. Dinkle makes some pretty compact connectors but since I need them to be up to 50 amp I had to use the larger ones. So far I am pretty happy with them.

https://www.dinkle.com/en/terminal_List/R-Screw-Connection?page=20&pagenum=20

Mark

 

[GParkins]

Phoenix makes a triple-stack block. Each layer passes through, so you can either jumper the three layers, or terminate three different layers of circuits.

Here's a link

They also make bridging clips to connect banks of terminals without impacting the actual terminals.

 

[itsnotrequired]

most of those european compact terminal blocks are rated for two conductors per terminal...but only if using metric sizes (i.e. mm2 vs awg). so if using metric, you can really pack a lot of common potential points into one bock. if using awg, technically limited to only one conductor per terminal.

 

[Tartan1]

Wire ferrules are also a nice option to double up wires into a terminal block. Ferrules are available in single and double versions for this purpose.

 

[GParkins]

most of those european compact terminal blocks are rated for two conductors per terminal...but only if using metric sizes (i.e. mm2 vs awg). so if using metric, you can really pack a lot of common potential points into one bock. if using awg, technically limited to only one conductor per terminal.

There is no difference between mm2 and AWG regarding the number of conductors you can fit into a terminal block slot. Phoenix publishes the max. mm2 of conductor section a block is rated for. For AWG, you just convert to mm2, and add to get the total mm2 you would like to use in the block. There is a recommended max. of 4 conductors, and all of the conductor must be concealed by the funnel in the block so that no conductor is exposed outside the block.

 

[GParkins]

Wire ferrules are also a nice option to double up wires into a terminal block. Ferrules are available in single and double versions for this purpose.

At least in the case of Phoenix blocks, ferrules are not required, as the clamping mechanism uses a pressure plate to bear on the conductors. Ferrules are only required when there is a screw bearing directly on the conductor. If you want to use them for aesthetics, I don't know of any reason not to.

 

[itsnotrequired]

There is no difference between mm2 and AWG regarding the number of conductors you can fit into a terminal block slot. Phoenix publishes the max. mm2 of conductor section a block is rated for. For AWG, you just convert to mm2, and add to get the total mm2 you would like to use in the block. There is a recommended max. of 4 conductors, and all of the conductor must be concealed by the funnel in the block so that no conductor is exposed outside the block.

maybe it depends on the manufacturer. phoenix gives a min-max range in mm2 so as long as the awg equivalent is within the range, i suppose it would be okay (it would definitely be okay from a practical standpoint, maybe not letter-of-the-law). but check out those dinkle blocks. they give two sets of connection info, one for iec in mm2 and one for ul in awg. the iec connection information gives guidelines for two conductors per terminal while the ul information does not, implying you can't have more than one conductor on a terminal in a ul application.

ah, standards...