do we "NEED" the power distribution block

[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.

[Al Skierkiewicz]

Note that the drawing and instruction sheet in your link all have "Rockwell" on them. I believe that the drawing was made for FIRST but that the instruction sheet is the one provided to installers by Rockwell.

[seanl]

are the ground wires from the speed controllers that go to the 4 cims required to be connected to the block. currently i have them connected through the breakers.

[Al Skierkiewicz]

Originally Posted by seanl

are the ground wires from the speed controllers that go to the 4 cims required to be connected to the block. currently i have them connected through the breakers.

Yes, that is the recommended method. See the latest revision of the electrical drawing and the Tips & Guidelines. It also minimizes the voltage losses to the RC due to the high currents of the motors passing through the smaller fuse panel. I know this is hard to visualize but the current provided to a motor (speed controller power in) and the current returning from the motor is the same. Since a Chalupa motor stalls at a over 100 amps, that current is flowing through both the red and black wire. For every foot of #10 (black or red)that equates to a 0.1 volt drop.

[seanl]

i know that it is what is recommeded but would we pass inspection if its connected through the breaker.

[Al Skierkiewicz]

Sean,
I would say that this is a question for the Q&A to be sure. However, in my opinion, I would say no, under this part of the robot rules...
<R57> The 12V battery, the main 120-amp circuit breaker, the power distribution block, and circuit breaker distribution panels must be connected as shown in the 2007 Power Distribution Diagram.
Sorry.

[T3_1565]

can you use more than the amount of blocks given to us (we happen to have a lot lying around) it would be nice to have easy access for everything

[Al Skierkiewicz]

I am not sure you need them or would want to run different paths for your positive and negative wiring. You are talking about the Rockwell blocks? If you are using the small black panels, I believe there is no limit.

[T3_1565]

well we might not have them hooked up right then, I will have to look, but as it is.. we have our motors connecting through them to the victors and all the grounds of the victors go through different ones to form one wire and go to the ground terminal on the fuse block ( I'm sorry if it is confusing I'm not the electrical guy lol) so if there is a way in which we have to use these please tell so I can get them to rearrange now.

Edit: I just read was posted above me and I shall look at this power distribution diagram.

[Al Skierkiewicz]

T,
Let me know if you need more help with this. If you PM me I can give you my email if that would help.

[BlackShadowFox]

Well I know this is kind of late in the game for the last year but I have a good feeling that they are going to bring the power distribution block back. Reason could be due to a contract or donation reason but that is just my guess and shouldn't be taken into to consideration because the true point is that it is required in the rules but however there is a few scenarios that have me confused on why you need the power distribution block.

Some information on wiring:

With the current battery cables at the gauge that they are it would be pointless to go a high gauge or doubling up on the same battery gauge in the controller system because your can’t exceed the power limitation set by that battery cable. The higher the gauge the more power can flow.

The longer the cable the more energy is lost due to resistance. So for example when Tomas Edison wired up a town with dc the power could only go a limited range because of the resistance.

Some of you said that the power Distribution block is a standard there I agree but grounding pins and other power products in that nature are also standards.

Questions and scenarios:

So if I were to make a robot with Only one ATC fuse panel ( 20/30 a ) would I need to use the power distribution block? Its required in the rules and also on the check list but it would serve no purpose.
(Because as far as I see I have only one grounding pad and one positive pad creating no reason for a Distribution block)

Ok let say I’m using two to three and maybe four fuse panels, using the fact from above about the battery’s wire gauge and also that the maxi fuse block is essentially a distribution block why would I need another distribution block when there are ones in place already? You may say resistance and you may have a point but I could say the same thing about the new distribution block.

I don’t know how many of you have looked at the inside of the New distribution block and understand how it works, but if you look there is a lot of wasted space. If you notice that in the base there are 3 squares, now if I was to drill a hole through all these squares I could run the battery cable through them that FIRST supplies. I also could do some other added things but as things go all will say I’m not allowed to tamper with these devices since I could make it unsafe not like I have shocked myself with an outlet 4 times or more to learn my lesson.

Now let’s say I have a maxi fuse block and an ATC fuse panel. Could I ground the four 40 AMP speed controllers to that ATC fuse panel and not have to use the negative half of the distribution block?

Final Note

I would go into mounting but that is another story for when this year is revealed. Also I would like to note that though I don’t like the distribution block for the robot purposes I do enjoy it for my other projects such as my other post called the cart files where it would help with later modifications.
Well I know there is probably more cases others can think of that I’m missing but it is 2:30 am and I’m tired so I leave it for you to debate on and create your own opinions because who am i but a student that doesn't have a degree in electrical like some of you.

[Gboehm]

I didn't mind the block. I don't know why people are so upset, its required so complaining about it wasn't gonna change. The wires came loose, it was nature of the beast. The 2005 set up was nice, but we don't have it. Oh well.