Test Bench TERMINALS needed for 240-1+ to 480-3+ - USA 2

[FreddyZ]

Surely someone sells such a thing?

I have made my own out of UHMW plastic and screws and fiberglass rod with springs so far. There was a recessed hole to insert the Unit To Be Tested's power cord wires into.... then the fiberglass rods press the strands against the contact screw within the plastic block, which is fed from a contactor within an enclosure. A 5th fiberglass rod enters the enclosure and operates a switch such that power is applied to the terminals only if the pinch rods are pressed against the wires/ terminal screws. The wire access holes are about 3mm diameter and the terminal screw is about 6mm down in, so a finger could not access the terminal in any event, nor can a dropped tool cause trouble.

We need to test 240V-1Ø with 3 wires [L-L-PE (Protective Earthing)], and 240V & 480V 3Ø 4-wires [L-L-L-PE]. The cables are Carol brand rubber coated SJOOW in 14-3 or 16-4 configuration; max expected amperage is about 5A per leg. We only need power the Device To Be Tested for a few seconds and verify speed, direction, and current draw.

I would prefer something like a heavy duty spring loaded clothes pin type apparatus that can grip each wire and hold it as the operator connects them. Similar to a connector I have seen on audio speakers, but for high voltage and maybe 10A capacity.

I can arrange some sort of safety to ensure that the power is off if hands can get near these connectors- e.g., an enclosure with a lid that cuts off power if the lid is open, like the above described tester connector.

Anyone know of a source for such repeated-use test machine terminals? I have tried searching the internet, and obvious places such as DigiKey.

Thanks so much for any assistance.

 

[FreddyZ]

I should clarify that I don't want screw terminals or anything that requires a tool to secure and release. Finger or hand actuated spring loaded pinch clamp.

 

[VEBill]

To confirm...

You're testing appliances with unterminated power cords?

(You'd want a GFI on the circuit in case the wiring gets mixed up.)

 

[MacGyverS2000]

Jumper cables have spring-loaded clamps at the end... four to a set.

But such a setup would scare the crap out of me to be near...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

Solid or stranded conductors?

Gauge of wire?

 

[VEBill]

Sorry, you've already answered the last questions. Disregard.

 

[VEBill]

http://www.ebay.com/itm/230981674238

 

[VEBill]

I searched on: wire test clamp terminal ZIF

ZIF = zero insertion force

Then browsed images for quick scanning of the results.

 

[jraef]

Side note: SJOW is NOT rated for 480V... 300V max.

"Will work for (the memory of) salami"

 

[Comcokid]

There are binding posts large enough for those wire gauges. Abbatron/HH Smith 1548-102 (black) and 1548-103 (red). Newark carries them, but I've found their less expensive at McMaster (they don't list them by the manufacturers name/pn).

Otherwise, I would buy a standard electrical distribution terminal block, remove the screwdriver screw-down, and replace it with a Threaded Tapered Handle (McMaster) with a stud of the right thread to extend it through a protective cover for the operator to use.

 

[ScottyUK]

These were commonplace years ago in UK repair facilities:

http://uk.rs-online.com/web/p/mains-test-blocks/0458926/

I haven't seen one used for 3-phase service but if you provided three separate blocks then you would be likely be OK. 480V/277V takes you slightly over the rated voltage of 240V but I doubt it would be of practical significance.

 

[FreddyZ]

Thanks, folks.
I had not heard of "ZIF" before. That should help in the search for candidates.

Yes, we need to connect to unterminated stripped stranded wire briefly in order to verify operation of the unit. These are agricultural units generally not required to be UL certified. We do need the tester operated by entry level personnel with as little risk of injury as possible- thus the power cutoff if terminal access is possible.

The two types of cord are:
240V 1-phase uses Carol brand SJOOW 3 conductor 14 AWG stranded rated 300V/90C
480V or 240V 3-phase uses Carol or Southwire brand SOOW rated 600V/90C 4 conductor 16 AWG

I like the ebay offering but there is only one photo, with no scale. Aha, the specs part says:

"Wire size clamp range 0.08-4 mm2 (28-12AWG)
Connection method Spring Clamp
Measured voltage EN 400V
Measured shock voltage 4kV
Pollution degree 2
Current intensity EN 32A
No. of connection Points 5
No. of potentials 1
Height 14.5 mm
Width 26.6 mm
Depth 20.5 mm"

Seems a little small in width at about 1" for 5 positions. Probably will do what we need though. I can buy multiples and use every other slot if need be. The AWG range of 28 to 12 seems perfect, as does the "insert and snap closed" operation. Now we just need that GFCI [three of them?] to cover all three possible power inputs. And a lid that cuts off power when open for access.

The British offering

http://uk.rs-online.com/web/c/connectors/mains-iec-connectors-accessories/mains-test-blocks/

shows only three positions, no provision for the 4th wire. The web page makes finding similar items difficult. That plus international purchasing hassles will probably rule out that choice.

 

[VEBill]

"...to cover all three possible power inputs."

You might want to basically have three separate workstations, or at least three physically separated set-ups. One for each voltage.

The worst approach (human factors, safety) would be to have a voltage selection switch that would eventually be left in the wrong position.

Good luck.