do we "NEED" the power distribution block

[seanl]

does the rules require us to use it or is it optional. because personally i see it as a waste of space and weight.

[sanddrag]

because personally i see it as a waste of space and weight.We all do. But, it is required, and you will not pass inspection without it.

[seanl]

yay time to rewire.

[Al Skierkiewicz]

yay time to rewire.
Please check the Tips and Guidelines for instructions on how to wire this critical part.

[efoote868]

do we "need" it? I'd say not; I can't see how it's application is remotely close to a robotics competition, where weight is a major factor in it.

But, since the rules are the rules, yes, you must have it in your robot. so you do "need" it.:mad:

[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]

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]

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]

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 (http://forums.usfirst.org/showthread.php?t=1755&highlight=rockwell) 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]

You know what they say about assuming...

You and me...both!

[BrianBSL]

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_1735_temp/Drawings/Battery%20Power%20Terminal%20Strip%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]

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]

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. :rolleyes:

[BlackShadowFox]

See what i said was not for my personal benefit. I do know some team that use drill motors for their drive trains and don't need the 40 amp fuse panel. Making them use a part for no apparent reason is pointless that is why some are upset also if you read what i said in the begging of my last post here was a series of possible questions that could arise and i stated the possibility of the power distribution block coming back. I was looking at it through a design stand point and no more not wining or any other thing because in the end rules are rules and if you don't follow you don't play.



People only see what they want to see.

[Al Skierkiewicz]

BlackShadow,
OK, you have a lot in your post that needs to be addressed....
You are correct that the longer a battery cable becomes the more power is lost, at 200 amps that amounts to about .1 volt per foot of wire (both black and red please) but that has nothing to do with the distribution panel.
Yes, you are also correct that a simple positive post and a negative post would be electrically identical but that implementation makes insulating the two posts difiicult leaving exposed electrical (high current and unprotected by breaker) connections.
Yes there is a lot of empty space inside the distribution blocks. These blocks cover a wide range of product and the size is meant to allow these different products to be stacked next to each other on the same rail. In practice, you could have #22 control wiring , #26 data cable, #18 low voltage solenoid wiring, relays, #12 or #14 AC 110 volt wiring and #6 or #4 three phase 208 volt motor wiring on the same set of blocks. The need to consider insulating all of these mixed schemes is accounted for in the design. The insulation between and among the blocks is designed to prevent arcing between terminals of more than 300 volts.
Yes, you could build the robot with one or two ATC fuse panels. The current drawn by the high current motors then flow through the same wires that feed the RC and as pointed out above, at 200 amps, that is 0.1 volt per foot. Add more motors (say four small and two large Chalupas) and the current can now cause a 0.3 volt/ft. drop. Add that to four feet of battery cable and the internal resistance of the battery and you are dangerously close to the 8 volt cutout of the RC. By splitting these high current loads away from the rest of the wiring as close to the battery as is possible allows the RC voltage to remain high while the motors receive less.
Yes, you could drill through all the blocks and attach the battery cables that way, but the manufacturer has provided a jumper module that is capable of high currents. If you design your distro properly, you can actually attach the battery at the center of a jumper and thereby split the currents right in the block.
BTW, to give credit where due, it was Tom Edison and the DC wiring, Ben was the nut with the kite in the rainstorm.

[BlackShadowFox]

Al Skierkiewicz Now that i think about it your right about Thomas Edison but when i wrote this was at 2:30 Am so thanks for the save.
But when you were talking about
"If you design your distro properly, you can actually attach the battery at the center of a jumper and thereby split the currents right in the block."
Are you trying to say their might be a part from this company that we could use?

[Al Skierkiewicz]

What I meant was, attach the battery leads to the center of a jumper and the current will split to both sides. If you tie in the battery at one end of the jumper then the currents all sum through the length of the jumper.