My team was planning on using purple and green Anderson clips on the green and white ends of our Victors’ wires. However, I just stumbled across this rule:
R59. All non-SIGNAL LEVEL wiring with a constant polarity (i.e., except for outputs of relay modules, motor controllers, or sensors) shall be color-coded along their entire length from the manufacturer
A. Red, yellow, white, brown, or black-with-stripe on the positive (e.g. +24VDC,
+12VDC, +5VDC, etc.) connections
B. Black or blue for the common or negative side (-) of the connections.
Wires that are originally attached to legal devices are considered part of the device and by default
legal. Such wires are exempt from R59.
What should we do about this? Will we fail inspection?
The connector housings are not considered to be part of the wiring, as far as color codes, are they? The wires need to be the correct color, but I don’t know of any rule that applies to the color of the connectors themselves.
The green/white output of the motor controllers is specifically exempt from the rule you quoted, since the polarity can change depending on the direction the motor is being driven. Even so, connectors are not required to be a specific color, as teams use non polarity specific crimp connectors and similar all the time.
except for outputs of relay modules, motor controllers, or sensors
This seems to imply that anything between the PDB and Victor need to conform to [R59], whereas anything between the Victor and motor does not. If your connectors are between the PDB and Victor, then you’ll likely want an official Q&A response on whether they’re included in the term ‘wiring’.
To me it’s pretty clear. They chose ‘wiring’ rather than ‘wires’ in that rule, which seems to imply they want all live wires and associated components between the battery and the motor controllers to be easily traceable by conforming to a subset of coloring. The ease of an inspector tracing wiring is to ensure proper control over the motors, for safety. These wires are LIVE as soon as the robot is turned on (even before it’s enabled), so safety is a definite concern. Anything after the motor controllers seems to be team choice. Yet, as always, this is just my interpretation of the rule.
If you’re looking to color code connecting pairs (this motor goes to this controller, etc), you could try colored zip ties, nail polish, or labels.
Connectors are not included in the color codes for wires. Asking that would be ridiculous. There are plenty of legal motor controllers that have screw terminal connectors on them, and it is standard practice to use a simple spade or ring connector with them. Most of those connectors are color coded according to the wire gauge they work with, I’ve never actually seen one that was color coded for polarity.
Oh, and what about the Anderson Connector between the PDP and the battery? That’s constant polarity, but the housing is not color coded as such. That’s as clear an indication as you can get.
What I find ‘ridiculous’ is the assertion that connectors are not included in the wiring and yet nowhere in the 2017 rules does it say that. Furthermore, the pink connector battery connector housing is specifically called out in the rules, but any other connection housing is not - thus it isn’t wrong to infer there are no other exclusions for [R59].
I agree with Jon: If I were inspecting (I’m a LRI) colored powerpole connectors would be OK.
That being said, what I think or say is irrelevant: The ONLY one whose opinion matters is that if the LRI at each of your events. If you want to be absolutely certain, have the GDC clarify the rule on Q&A.
Sorry if I gave offense, but honestly, the electrical color coding is taken from industry and has never included the connectors, either on robots or in industry. Encouraging someone to ask it on the Q&A potentially leads to the same issue we had a year or two ago with the question about velcro on the bumpers and all the problems that question caused.
Imagine the question gets asked, and the answer comes back that everything has to be color coded (likely from a poorly worded question, a misunderstood question, or answered by someone that didn’t understand the implications). Then how do you connect to some of these motor controllers? Spade connectors appropriate for 12 gauge wire do not come in black or blue. They only come in yellow or uninsulated. So now this hypothetical ruling would mean everyone has to go remove the insulation from their connectors and replace it with electrical tape. Oh, but does the electrical tape also have to match the color coding?
Asking the question only opens up a whole can of worms on something that has been standard practice in industry and FIRST for as long as I can remember.
So I’m sorry if I call it ridiculous… but that’s really the only word that comes to mind.
I’m not advocating to standardize on red or black for housings. I’m simply giving a perspective of interpretation from someone who isn’t in the electrical industry - like a vast majority of people (including inspectors).
It’s possible the GDC would see the question and issue a Team Update with a Blue Box for [R59] that says “Connector housing colors, such as <insert stuff here> are not included as wiring for purposes of this rule”. For the answer to the Q&A question, they would say “Please refer to Team Update N”. They do it for plenty of rules each year.
Anderson Power Products provide housings in many colors to help you color code connectors as a user. The rules support that ability by not including a rule governing the use of connectors (assuming they are appropriate for the load current). You may mix and match colors if you wish. The wire color is covered by a rule that mimics electrical color standards in use in the US and many other countries. This does not apply to automotive wiring as it would not be practical for that use. However, auto battery wiring does use the Red/Black convention.
I highly recommend that wiring that is polarized (always positive or always common) carry the convention to connector housings so everyone on your team can be sure. There is no convention needed for wiring that changes polarity, such as the output of a motor controller that feeds a motor that changes direction.