Main Power Terminal Blocks?

I’ve been laying out some diagrams for the electrical on this year’s robot, and the only components that I haven’t been familiar with are the new terminal blocks.

These are the modular square boxes that are intended to be attached to a supplied rail.
On FIRST’s supplied diagram, they are wired between the main breaker/switch and all of the breaker panels and components. I’ve never used terminal strips like this, I’ve just wired directly from the positive output on the main switch to the positive input on the component boards, and then used a separate terminal block to return on the negatives to.

So really, my question is, does anyone know if these terminal blocks have to be wired to the positive side of the circuit out of the main breaker?


The power distrubution block is not required by the rules. But, if you are using more than one circuit breaker panel, it would be good wiring practice.

I think it is required. See <R57>.

I also intepret <R57> to mean that the power distribution blocks must be used:

The power distribution block must be directly connected to the APP connector and main
120-amp circuit breaker. No other loads may be connected to the main 120-amp circuit

I don’t mean to be un-gracious, but what is the point for this new power distribution block? It is taking up a great deal more space and weight. The Maxi fuse block is designed to take like 4 or maybe even two gauge wire. The other panels have big enough lugs to take a terminal for 6 gauge wire. In the past, we would always run 6 gauge wire off the breaker to every panel. Why this intermediate thing? To me, it is like driving from Los Angeles to San Francisco by passing through Wyoming. Is there a good reason for it that I’m not seeing? If not, can we rally for a rule change so it isn’t required?

Okay, thanks for the info. I must have looked right over <R57> last night.

I agree though, that this seems to be less of a help than a hindrance… I’m gonna have to sketch my diagram out again, taking into account using a bit more large gauge wiring to fit this block…

That is exactly what I have been trying to say. It is MUCH more weight and less practical from my knowledge.

Can a controls mentor please explain the function of a power block I do not completely understand.


Honestly they are completely useless. From what i know what you always did is still allowed and is not a wrong way of doing it. These blocks are probably just a way for making the electronics look nicer.

I beleive its leagal to use last years power distribution block (altho i havent gotten all the way through the robot section). DIN Rails do add weight but adds a nice organization to your electronics. I do agree it does seem kinda redundant, we found out we will need more negative blocks then the amount we were given and much less positive as we are just using breaker panels for all of our victors, spikes, and the RC.

all the fuse panels are the exact same ones from last years, the power distribution box last year wasnt a DIN Rail but it was essentially the same thing just made of a solid block of plastic.

<R24> Individual COMPONENTS from ROBOTS entered in previous FIRST competitions may be
used on 2007 ROBOTS IF they satisfy ALL of the rules associated with materials/parts use
for the 2007 FIRST Robotics Competition.

Last years PDB does comply with the rules for the 2007 FIRST Robotics Competition because its the same exact thing as the DIN Rail just not on a rail.

Power Block.jpg

Power Block.jpg

Thanks guys. I stand corrected.

As much as these rail mounted blocks add weight and space, they are standard equipment in most modern electrical installations. Be sure to use the jumper accessory to connect all of the positive blocks together and all of the negative blocks together. These blocks will take #6 wire and I recommend using only #6 to feed the 40 amp Maxi block. It is best to strip back 1-1/2" of insulation and then fold over the strands, twice, so that they fill the entry hole in the Maxi block. This will give you a reliable connection that will not loosen over time.

Please watch the team updates for a change on these though. I feel there is an error in the electrical diagram as far as the negative battery side wiring is concerned. Negative lead wiring should follow the same distribution as the positive lead wiring, i.e. all black wiring should return to the DIN blocks, not a common point. Remember all current flowing out of the battery on the red wire, returns to the battery through the black wire.

I take this to mean we cannot use the 2005 All-in-one Breaker Panel

And as a side note, where is the power distribution diagram? I can’t seem to find it.

The diagram was on the documentation area of the website. I believe the electrical rules prevent the use of last year’s hardware and more importantly, the IFI breaker panel.

this how you get to the power diagram.
go here:
go down to Section 8 - The Robot

Ah yes, thank you.

And that’s what I thought. Poo, now I get to redesign the electronics box.

The newly revised Tips and Guidelines is now available on the First website. As I was reviewing it, I found that the Guide shows what my belief for correct wiring of the negative lead blocks and 40 amp returns should be. Please review for your own electrical system design.

I am wiring up our power panel with the RC controller, spikes, and victors and have a few questions:

  1. What guage wire is recommended to tie the heavy duty fuse block to the victors? These have 40 A fuses so I am guessing (10 or 12 awg?)

  2. What about the fan motors on the victors? I am assuming these are12v- where do most people connect the fans to for power, (fuse panel for always on or something else)?

  3. I am using 14 AWG between the fuse block and the spikes, is this the correct guage to use for this?

  4. I got one small bag of quick connect push on terminal with our kit but these don’t seem to be enough. Is ther ea problem with using any push on lug or do they have to be from the same mfg. that provided the ones in the kit?

  5. Does anyone have a recommendation of which RC module output should control which spike or victor based upn the default code?

Thanks in advance.

I looked briefly at the blocks, and the center jumpers. I noticed that the center jumpers look a little bit like a fuse…although I found no mention in the AB documentation of current limits of the jumpers in my brief reading.

But I do like the power blocks, they make me feel better about offering some protection in case the small wires from the 120 amp breaker to the individual fuse panels accidently shorted. I noticed that the wiring on last years robot offered no protection for certain types of wiring problems, and I think the new distribution block could make it safer.

(I’m an ME, not an EE, so maybe someone could tell me if I’m on the right track?)

In the manual, Section 8 the Robot, Rules 87-98 will give you all the electrial specifics you are seeking.

In the default code from IFI, PWM01 is mapped to Joystick Port 1 X axis and PWM02 is mapped to Joystick Port 2 X axis. Typically they connect to the drive motor victors, but it’s completely up tp you as to how you’ed like it to work