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Recommend a good Terminal Barrier for a newbie

Joined
Jun 9, 2008
Location
Burbank, CA
Recommend a good Barrier Strip (Terminal Block) for a newbie

Guys,

Building the control panel for an oven.

24vdc control circuit and 220 single phase power circuit.

Thinking a DIN rail type of barrier strip/terminal block

Looking for brand suggestions. Also, spring type or screw?

Thanks!

Chuck
Burbank, CA
 
Last edited:
If you need >2 connections at a terminal, using a 3-hole or 4-hole terminal is easier, smaller and more reliable than using 2-holes with linking bars, especially if using push-in link bars. Something like this.

Multi-layer terminals are convenient for controls: COM,24V, and the signal all in one stack. Run busbar along the top for the first two.

For small controls, always get terminals rated a few sizes larger than the wire you plan to use. This makes life easier when dealing with ferrules or unruly cable. Not such an issue with your 40A+ power cabling, generally.

Push-ins are good but you want the type with a release button, not trying to dig around with a screwdriver.
 
I know many disagree, but I just plain do not trust ANY "push-in" connector especially not for a power application.

A screw type connector? Sure, as long as it is the type where the screw tightens a plate down on the wire. The regular old type where the screw directly contacted a wire wrapped around it, or caught under the end of it is another baddie in my book, especially when used with stranded wire.
 
A screw type connector? Sure, as long as it is the type where the screw tightens a plate down on the wire. The regular old type where the screw directly contacted a wire wrapped around it, or caught under the end of it is another baddie in my book, especially when used with stranded wire.
I thought you were supposed to put terminals on the ends of the wire for those, then screw down on the terminal ?

Will admit to occasionally skipping that step tho. Just temporarily, of course :)
 
I know many disagree, but I just plain do not trust ANY "push-in" connector especially not for a power application.

A screw type connector? Sure, as long as it is the type where the screw tightens a plate down on the wire. The regular old type where the screw directly contacted a wire wrapped around it, or caught under the end of it is another baddie in my book, especially when used with stranded wire.

Agree all counts.

Also MY "personal" observation of too-many-years is that the now near-as-dammit "ubiquitous" DIN rail goods are best at making rugged things fragile, simple things complicated, and everything more expensive than ever they needed to be.

Sorta like one-size fits all panty-hose in infinite color, weave, decor, "denier", all trashed at the first snag..... when wimmin have been at their best for half a million years without them.

And still ARE! Praise God in her infinite wisdom as to "screw type connectors" or "push-in", either one.
 
A large diameter stranded wire end can be dipped in a little flux and flooded with solder. Keeps the stands from flattening out.

More than once I fixed weird problems that were due to barely conductive wire connections that had to be tightened down a second or third time.
 
A large diameter stranded wire end can be dipped in a little flux and flooded with solder. Keeps the stands from flattening out.

More than once I fixed weird problems that were due to barely conductive wire connections that had to be tightened down a second or third time.


Solder squeezes down in a "cold flow" manner. That's like tightening on plastic.... it runs away from the pressure.

A ferrule, such as EG mentioned is indeed the best and "right" approach, but the plate type connector does not seem to need that, and it is not "specified" in most cases.
 
Wait - for an oven? How hot will the terminal boards get?

(also concur on tinned, stranded wire best avoided for clamp down lugs as they will slack off over time - discovered this when I had been tinning stranded S cord conductors going into Hubbell cord caps. I discontinued that practice)
 
I thought you were supposed to put terminals on the ends of the wire for those, then screw down on the terminal ?
Will admit to occasionally skipping that step tho. Just temporarily, of course :)

Even these can be problematic. Manufacturer used these on their equipment made overseas. Tested extensively. Shipped air freight to our site in the US. Run sucessfully for several cycles (over a few months). I come in one morning and the system is dead. Whoops. Tracing out with a wigger shows the main hot lead, fed from a breaker in the console, has no power. But the lead *at* the breaker is live.

The crimp-on terminal feeding the downstream stuff on the rail had an insulator where the crimp met the tab. The tab terminal was over-inserted into the screw-down contact, and the pressure was mostly on the *insulator*. Mostly. There was enough metal-to-metal contact for the thing to work at the build location, survive the air trip, and run for quite some time. Until it quit in the middle of the night. For me to find monday morning... Have photos....
 
Soldered connections under screw terminals is forbidden in NZ regs. As mentioned, you get cold flow, plus it also tends to fracture individual strands at the edge of the solder when subjected to vibrations.

Spring terminals have the advantage of being self-tightening, but don't necessarily have enough clamping force if you're using ferrules and they aren't adequately crimped; it will grip onto the ferrule, but not bite through into the cable.
 








 
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