Burnt Fuses

[Jordan2389Diaz]

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

[Racer26]

...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.

[Mark McLeod]

What kind of motor did you attach to the Spike?

[apalrd]

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.

[Tom Line]

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.

[Foster]

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!

[Joe Ross]

Originally Posted by Foster

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.

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

[Foster]

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

[Zholl]

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?

[Joe Ross]

Originally Posted by Zholl

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?

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?

[apalrd]

Originally Posted by Zholl

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?

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>

[Zholl]

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.

[Al Skierkiewicz]

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.

[Zholl]

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"

[Al Skierkiewicz]

Originally Posted by Zholl

I'm just asking about what I've been hearing since I'm the "chief delphi guy"

Everyone should be the Chief Delphi Guy!