Burnt Fuses
 

:cool: My team's CRio spike is burning fuses; does anybody know how to fix the problem.:confused:

Re: Burnt Fuses
 

...The cRIO isn't supposed to be on a Spike.

EDIT: There is no team-accessible fuses/circuit breakers in the path to the cRIO. There is an internal fuse inside the cRIO that you're supposed to send it back to NI for repair, and there may be one in the PD board. The cRIO is to be powered from the 24V output on the bottom of the PD board.

Re: Burnt Fuses
 

What kind of motor did you attach to the Spike?

Re: Burnt Fuses
 

You are allowed to replace the fuse on the Spike with a Snap-Action circuit breaker of 20 amps (no more), the same kind used by the PD board.

You cannot use CIM or Fisher-Price motors on Spikes, they draw too much current.

The 555 and Window motors are fine for Spikes. The compressor uses one too. You should replace the fuse on the Spike for the compressor with a breaker, the starting current of the compressor is enough to cause burnt fuses.

Re: Burnt Fuses
 

I'm going to take a wild guess and say this is the spike powering the compressor.

It is a known issue that the start-up amperage of the compressor far exceeds what a normal fuse can handle. You need to use a snap-action fuse that automatically resets - they will handle the overcurrent for long enough (usually) to get past the compressor start up until the compressor drops to the steady-state draw of lower amperage.

Re: Burnt Fuses
 

I'll jump on the "change the fuse to a breaker on the spike that controls the compressor" bandwagon. The compressor will draw more than 20 amps when it tries to start when the compressor is hot. And if your robot is like ours the compressor runs a lot.

The rules are clear on the breaker in a Spike is only for the compressor. If you are going to put a motor on a spike (not the FP or CIM motors) you must use a fuse. Make sure you check the size of the fuse.

Not to push Al off his "use big wire" soapbox, but use big wire. Use #10 wire when possible. Get all the electrons you can to each device. Smaller wires mean voltage drop, lower voltages with the same load means higher currents. Higher currents means burnt fuses. Use big wire!

Re: Burnt Fuses
 

That was the rule in previous years, but not this year.

Re: Burnt Fuses
 

Sorry, Joe's right, <R60> F The fuse on the Spike relays may be replaced with a 20 Amp Snap-Action circuit breaker.

Re: Burnt Fuses
 

here's my question. since the breakers for the PD board don't actually fit the slot on the spike, should we use a standard automotive breaker of the same type which actually fits the spike without falling out?

Re: Burnt Fuses
 

We have not had any trouble replacing the fuse in the spike with a 20 amp circuit breaker from the kit. Could you further describe the problem you're having?

Re: Burnt Fuses
 

The breakers on the PD board DO fit in the Spikes. You should be using the 20's, they fit just fine. Both the breaker and fuse are Automotive ATO fuses/breakers, which is what the Spike wants. You must use Snap Action breakers, see <R60>

Re: Burnt Fuses
 

we've put the 20A breaker from the kit into the spike. however, it doesn't seem to seat properly in the spike, so it comes loose and falls out. so we're trying to figure out if it can be replaced with a 20A snap-action breaker from a local automotive store, which should be more certain to fit that slot.

Re: Burnt Fuses
 

OK,
The compressor from the KOP has a 25 amp start and 10-12 amp run current rating. The fuse in the Spike is guaranteed to blow. (OK I guarantee it will blow) Maybe not the first or second time but it will blow when you need it the most.
The breaker will only insert one way into the Spike so turn it around if it looks like it can't full insert. It is also possible to insert the breaker (or fuse) at an angle and miss the terminals altogether.
Please remember that off board compressors are required to have a Spike powering the compressor under Crio control. The compressor can be off board but the Spike and pressure switch must be on board.

Re: Burnt Fuses
 

alright, so I guess I'll check that it's in right first thing tomorrow when I get into the shop. I haven't actually worked with the part in the last couple days, so I'm not entirely sure what's going on with it exactly, I'm just asking about what I've been hearing since I'm the "chief delphi guy"

Re: Burnt Fuses
 

Everyone should be the Chief Delphi Guy!

Re: Burnt Fuses
 

wrong, the pressure switch may be off board, but only if the pressure in the tanks is 60 PSI

Re: Burnt Fuses
 

<R75> ...
The compressor may be mounted on the ROBOT, or it may be left off the ROBOT and used to pre-charge compressed air in the storage tanks prior to bringing the ROBOT onto the FIELD. Off-board compressors must be controlled and powered by the ROBOT.
Followed by this note...
The only difference between an on- and off-board compressor is that the off-board compressor is physically removed from the ROBOT. The intent of this rule is to permit teams to take advantage of the weight savings associated with keeping the compressor off-board. However, using the compressor off-board of the ROBOT does NOT permit non-compliance with any other applicable rules.

The pressure switch, Spike relay, etc. remain on the robot and all parts of the remaining pneumatic rules apply.

Re: Burnt Fuses
 

Al, the main regulator may be left off the robot when using an off-board compressor with 60PSI tanks per R76-D.


The pressure switch must be connected to the high pressure side of the system per R78. As the high pressure side of the system is not on the robot, it would seem that the pressure switch not only can be held off the robot, but must be if the main regulator is also held off the robot.

Re: Burnt Fuses
 

Kevin,
Sorry, I missed the reference to the 60psi at the end of the post. Trying to make a ham radio contact with Milan and writing at the same time. Although you can loose a little weight with this configuration, storing at 60 psi is risky business. I expect to see some teams using this approach early in the season, I do expect it be dropped later though. I don't expect to see a lot of teams at 120 lbs. so the weight savings is not that critical.