Team 2853 presents...their Book of Electrical

[Zaque]

Originally Posted by cgmv123

Also note that this is only legal when powering a compressor.

Can you point me to the rule that says this? I thought this was the case, but one of our mentors disagreed with me and asked to see the rule. I looked, and much to my surprise could not find anything. Or is this an exception to the "anything not explicitly forbidden is allowed" rule?

[Joe Ross]

Originally Posted by Zaque

Can you point me to the rule that says this? I thought this was the case, but one of our mentors disagreed with me and asked to see the rule. I looked, and much to my surprise could not find anything. Or is this an exception to the "anything not explicitly forbidden is allowed" rule?

R64 makes it illegal to modify the spike (which presumably includes changing the fuse for a circuit breaker) and then R64-E specifically allows the use of a circuit breaker when running the compressor.

[SuperCat]

WOW!! This is incredible and clearly had an impressive amount of work put into it. I will definitely look at this again and learn from it more. I never knew cRIO stood for something!! This guide really explains why specifically the stuff we wire works (and how it works!!), which is important. Thanks so much!!

[KevinG]

Originally Posted by Joe Ross

R64 makes it illegal to modify the spike (which presumably includes changing the fuse for a circuit breaker) and then R64-E specifically allows the use of a circuit breaker when running the compressor.

Interesting, I was inspecting robots all weekend and that was never brought up. I wonder what the logic behind limiting a breaker to only the compressor is.

The document should be updated to emphasize that snap breakers are recommended (but not required) for the compressor, as the current draw on the compressor could be enough to pop the fuse when it starts.

[Zaque]

Originally Posted by Joe Ross

R64 makes it illegal to modify the spike (which presumably includes changing the fuse for a circuit breaker) and then R64-E specifically allows the use of a circuit breaker when running the compressor.

Well, we have now been through three regionals(one last year and two this year) with breakers instead of fuses on spikes controlling window motors.

[BabyUnicorn]

Wow! Fantastic resource! I'm really interested in electrical so this should help a ton! Thanks so much. Great work.

[Al Skierkiewicz]

As Joe pointed out R64 allows the modification for a 20 amp circuit breaker for the use with compressor only. This is an exception rule so it won't be found with a standard search.
R64
The Driver Station software, cRIO, Power Distribution Board, Digital Sidecars, Analog Breakouts, Solenoid Breakouts,RSL, 120A breaker, motor controllers, relay modules, Wireless Bridge, 12VDC-5VDC converter, and batteries shall not be tampered with, modified, or adjusted in any way(tampering includes drilling, cutting, machining, gluing, rewiring,disassembling, etc.), with the following exceptions:
E. If powering the compressor, the fuse on a Spike H-Bridge Relay may be replaced with a 20A Snap-Action circuit breaker.

This is following a recommendation by VEX (dating back to 2002 or earlier) that for a KOP compressor only, the start current was high enough to blow the fuse but not damage the relay contacts. All other motors that have a stall current in excess of 20 amps will damage the contacts and internals of the Spike and obviously void the warranty. Breakers may not be used in place of the fuse on other FRC motors to prevent catastrophic failures.

I think it is also appropriate to point to the following highlighted rule. I receive at least one or more queries on this subject a week during build.

R35
The one ROBOT battery, Anderson Power Products (or APP) Connectors (p/n SB50), the one main 120-amp (120A)circuit breaker (Cooper Bussman P/N: CB185-120), and the one Power Distribution (PD) Board shall be connected as shown in Figure 4-11.