I don’t see anything in R57 or R44 regarding what wire size to use for the Signal Light. Am I overlooking something? It looks like everything else is spelled out in detail.
I would consider it a branch circuit of the DSC, so [R43-C] and [R44] would then be applicable.
doesn’t R43-C pertain to the wiring supplying the DSC, instead of what the DSC supplies to downstream circuitry?
R44 doesn’t mention the RSL at all…
This one does concern me: I just cut a 2 wire 0.1" female jumper in half, but it’s awful small AWG, and I just don’t have anything heavier with a female header lying around.
Looks like least at 20AWG. If you use 18 AWG you should be completely rule compliant. Needs to meet the color code requirements in rule R45.
My issue with the 20 Amp breaker limitation is that pretty much everything else on the DSC is a 5V control signal running off of pwm cables. The RSL runs off of pwm size terminals as well, but I’m not sure what voltage it uses (I guess I could measure it). Since the RSL requirements (R55) are under command and control I would assume 5V but not sure.
The RSL runs off 12V. If this year’s [R43-C] and [R44] apply to it then I can count on one hand the number of legal robots I have seen since the RSL was introduced. Most teams use either the KOP 2-wire jumper or a PWM cable, very few use the “correct” Molex connector.
Yeah, I was looking at our most recent robots and found one with 18 AWG and one with a PWM, which is why I thought I’d ask.
All,
The RSL is fed through a 1.1 (hold)/2.2 (trip) amp breaker on the DSC. At this current standard PWM cables are sufficient. Recommended is #22 or larger as it is easier to terminate in the screw terminals on the RSL.
Sufficient, yes. The paranoid in me fears the lack of explicitness in R44 being coupled with a grouchy inspector…
You can look at the Inspection Checklist if it will help sooth the paranoia.
Lead Robot Inspectors have the experience and training to know what is common practice for this component.
…and the Q+A comes through:
Q. What is the minimum allowed wire size between the Digital Sidecar and the Robot Signal Light?
A. There is no minimum listed.
My reasoning was that R43-C specified the fuse for the DSC circuit and that R44 specified the wire gauge for branch circuits from the DSC, which includes the RSL. Of course, if the GDC has ruled that there’s no minimum, then there’s no minimum wire.
You can also hack down a 1x3 .1" header to be a 1x2; there were a number of 22AWG female PWMs included in the KoP.
We connected ours with a normal PWM cable, but stripped off the white wire and cut off that 1/3 of the connector…it works, the light blinks, the inspector should be happy.
(fast forward to about 1:10 in the video)
Try not to think too much about this stuff 