do we "NEED" the power distribution block

[CardcaptorRLH85]

I have a question about that power block. Does it add any type of safety advantage? I'd hope that FIRST wouldn't purposely add required weight without cause. I'm only asking because I truly can't see the advantage of having it over not having it.

[Al Skierkiewicz]

Originally Posted by CardcaptorRLH85

I have a question about that power block. Does it add any type of safety advantage? I'd hope that FIRST wouldn't purposely add required weight without cause. I'm only asking because I truly can't see the advantage of having it over not having it.

Although I wasn't part of the process, I can't answer for First. However, this type of block is in constant use in the electrical industry and is quickly becoming a system desired by many Electrical Engineers. In addition to the blocks which you are now familiar with, relays, timers, circuit breakers (even 3 phase and motorized trip) computer interface, power supplies, etc. are all becoming available for use with the DIN mounting rail system. Other then the added weight and larger size than the IFI panel (which was a perfect match for our robots) this panel may make it easier for rookies to get wired up with a minimum amount of tools.

[BrianBSL]

Here's my view on this:
Is it an improvement on the IFI panel? Definitely not. That was a nearly perfect for our robots and its a shame to not be able to use it.

However, I would say it is an improvement over the 2k4 system - as it adds the ability to ground the 40A motors to something other than the FASTON connectors on flimsy 20/30A block, and allows you to eliminate the FASTON's from the high current motors (we use Anderson Powerpoles everywhere instead). It also eliminates the "stacking" of ring terminals for the 6ga connections that could be more likely to cause intermittent connections (as multiple ring terminals on a single stud means more possibilities of moving wires, more likely that the nut will loosen). The weight is annoying - but not as annoying as the 40A MAXI block. It also removes more 6ga ring terminals from the system and replaces them with simple set screw system, which is easier to terminate correctly than a large crimped ring terminal.

But oh well, we have to live with it.

[Kris Verdeyen]

Has anyone found a distributor for the Rockwell Block?

Personally, I am trying to give this thing the benefit of the doubt. I, like everyone, I guess, preferred the 2005 all-in-one solution, but we gotta roll with what first gives us.

One quick note - we have discovered that it's easy to think that you have the 6 AWG wires in place without actually having a solid connection, so be sure to open the screw up all the way, and to give the wires a serious tug after you screw them down. Otherwise, you might see battery wires heating up, and large voltage drops with high current draws.

[Joe Ross]

Originally Posted by Kris Verdeyen

Has anyone found a distributor for the Rockwell Block?

Our local Rockwell Automation distributor does not have any in stock. Minimum order of each item is 50.

If somebody could find a distributor that stocks them, that'd be great. Otherwise we might try to pool an order.

[youngWilliam14]

I'd just like to know one thing: are we allowed to cut the yellow jumpers to fit just two or three blocks? I'd love to get rid of the red and black blocks that I won't be using.

[MikeDubreuil]

Originally Posted by youngWilliam14

I'd just like to know one thing: are we allowed to cut the yellow jumpers to fit just two or three blocks? I'd love to get rid of the red and black blocks that I won't be using.

According to FIRST's answer in the Q&A, I would say yes.

[Mike Martus]

Be very careful cutting the jumpers. I would advise against it.

They sell jumpers for two blocks - I was told at a Bradley dealer, I did not order them however.

[Al Skierkiewicz]

William and Mike,
I don't think that the Q&A fully addressed the cutting of the jumper plugs. If that is allowed in the future, it must include a note to fully insulate the cut end. Quite frankly, the majority of weight is already there, and having an extra block to add functionality later would be a desirable thing. If you are using a four motor drive and 40 amp breakers, you need at least two red and three black blocks anyway.

[MikeDubreuil]

By my possibly wrong interpretation, by virtue of telling us we don't have to use all the blocks FIRST is telling us we can cut the yellow jumper. The yellow jumper will not fit if you do not cut it. I would assume the person answering the Q/A would know this. You know what they say about assuming...

I will make sure the teams I mentor add a strip of electrical tape on the metal exposed end of the jumper.

[Al Skierkiewicz]

Originally Posted by MikeDubreuil

You know what they say about assuming...

You and me...both!

[BrianBSL]

Originally Posted by Al Skierkiewicz

William and Mike,
I don't think that the Q&A fully addressed the cutting of the jumper plugs. If that is allowed in the future, it must include a note to fully insulate the cut end. Quite frankly, the majority of weight is already there, and having an extra block to add functionality later would be a desirable thing. If you are using a four motor drive and 40 amp breakers, you need at least two red and three black blocks anyway.

The instructions on assembly for the module specifically state that it can be cut: http://www2.usfirst.org/2007comp_173...Strip%20R3.pdf

15) The assembly may be shortened as desired by removing the extra terminals and cutting the DIN rail and the center jumper bar(s) to the desired length(s).

In addition, a 4 motor drive with 40A breakers, and only one 20/30A fuse block could be satisfied with 2 red and 2 black, as the same document states that you can put 2 10ga or 3 12ga wires in the same connection:

Maximum Wire Size and Max Quantity Allowed per 1492-J16xx Terminal
1 - #6 or
1 - #8 or
2 - #10 or
3 - #12 or
4 - #14 or
4 - #16

(2 connections for 4 12ga wires and 2 connections for 2 6ga wires on the black, 3 connections for 3 6ga wires on the red).

Given that these are the instructions they are providing us on how to assemble this, unless there is a rule that specifically makes this illegal (which I was unable to find), as far as I am concerned it should be legal.

[Al Skierkiewicz]

Brian,
I agree that the instructions from Rockwell say it can be cut. But the normal use of this system is inside an enclosure where there will be no contact with other parts, electrical and mechanical. Our use has not been fully considered for insulating the cut ends and I am hoping that the GDC addresses this in the future.

[BrianBSL]

Originally Posted by Al Skierkiewicz

Brian,
I agree that the instructions from Rockwell say it can be cut. But the normal use of this system is inside an enclosure where there will be no contact with other parts, electrical and mechanical. Our use has not been fully considered for insulating the cut ends and I am hoping that the GDC addresses this in the future.

The instructions don't seem to be generic, however, as the drawing has FIRST in the part number, and the written instructions specifically reference that drawing.