Al's Annual Inspection Thread 2015

[MrRoboSteve]

It's not an unusual issue, even for experienced teams.

I was inspecting the wiring from our CIM motors back to the speed controllers, and asked whether they had looked at the wiring table. Turns out they matched the wire off of the CIMs, rather than using the table. Fixing it is now on our punch list.

[JamesCH95]

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

[ATannahill]

Originally Posted by JamesCH95

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

The pressure relief valve must be attached to the compressor with legal hard (non tube) fittings, so if you chose to install the NPT to plastic plug fitting, it must be past the pressure relief valve.

Originally Posted by R76

The relief valve must be attached directly to the compressor or attached by legal hard fittings (e.g. brass, nylon, etc.) connectedto the compressor output port. If using an off-board compressor, an additional relief valve must be included on the ROBOT.

[MrBasse]

Originally Posted by JamesCH95

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

[ATannahill]

Originally Posted by MrBasse

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

I believe that modification is legal under R65-C since it is pre-existing threads.

[JamesCH95]

Originally Posted by rtfgnow

The pressure relief valve must be attached to the compressor with legal hard (non tube) fittings, so if you chose to install the NPT to plastic plug fitting, it must be past the pressure relief valve.

True... but irrelevant to my question.

Originally Posted by MrBasse

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

Removing a pre-installed fitting would be like changing the terminal screws on a Victor. Yeah, it's not precisely the original hardware, but from a safety and function perspective it hasn't changed.

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The port in the compressor is 1/8NPT, so attaching normal hard-fittings and tees is the same as attaching to the steel part, it just fits into our robot a bit more easily.

[MrBasse]

Originally Posted by MrRoboSteve

It's not an unusual issue, even for experienced teams.

I was inspecting the wiring from our CIM motors back to the speed controllers, and asked whether they had looked at the wiring table. Turns out they matched the wire off of the CIMs, rather than using the table. Fixing it is now on our punch list.

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG? Are we trying to say that the manufacturer is not using the proper wire? A CIM on a 40 AMP breaker will draw a good amount of current if you tell it to, but why doesn't the CIM wiring dictate what wire is used between the breaker and the speed control?

How does it make sense that I would have to crimp 12 AWG wire to 14 AWG wire after the speed controller to be legal? How does that help?

[MrBasse]

Originally Posted by JamesCH95

True... but irrelevant to my question.



Removing a pre-installed fitting would be like changing the terminal screws on a Victor. Yeah, it's not precisely the original hardware, but from a safety and function perspective it hasn't changed.

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The port in the compressor is 1/8NPT, so attaching normal hard-fittings and tees is the same as attaching to the steel part, it just fits into our robot a bit more easily.

I guess I would counter by saying that you can modify electronics practically all you want. Pneumatics have painful rules in place to prevent accidents that may happen when people don't understand a system.

R65 C might give you a little leeway with that idea though since you are using the existing threads.

[JamesCH95]

Originally Posted by MrBasse

I guess I would counter by saying that you can modify electronics practically all you want. Pneumatics have painful rules in place to prevent accidents that may happen when people don't understand a system.

R65 C might give you a little leeway with that idea though since you are using the existing threads.

Are you sure about that? See R55.

R65-C is why I assume our actions are legal, but I just want to double-check with the in-field experts.

[rich2202]

Originally Posted by MrBasse

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG?

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

[cgmv123]

Originally Posted by MrBasse

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG? Are we trying to say that the manufacturer is not using the proper wire? A CIM on a 40 AMP breaker will draw a good amount of current if you tell it to, but why doesn't the CIM wiring dictate what wire is used between the breaker and the speed control?

How does it make sense that I would have to crimp 12 AWG wire to 14 AWG wire after the speed controller to be legal? How does that help?

Originally Posted by rich2202

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

CIM wire leads also have insulation that can take more heat than the insulation that's on most wires.

[rich2202]

Originally Posted by JamesCH95

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

I think "installed" is the key word. R65 says the original condition. "optional" parts are not part of the original condition.

Now, if it came with it installed, then the question is whether R65-C applies since you would be "disassembling" to remove the NPT fitting, and not "assembling".

[rich2202]

Originally Posted by cgmv123

CIM wire leads also have insulation that can take more heat than the insulation that's on most wires.

Another thought:

FIRST doesn't want you replacing wires that were not intended to be replaced. Thus the concession granting exception to using wire as supplied by the manufacturer.

[Jon Stratis]

Originally Posted by JamesCH95

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The only part that is required to be connected by hard fittings is the relief valve. Hook up a T with a relief valve on it, then use some tubing to located the gagged and switch and such someplace more accessible.

[scca229]

Originally Posted by rich2202

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

Just to verify:

PDB <-> 40A Breaker <-> 12AWG wire <-> Victor <-> 14AWG wire directly attached to CIM

Legal?