Snap Action Breaker Alternative

[NWChen]

I'm working on a non-FRC robot using the old (2009-2014) PDB. The normal competition legal 20A/30A/40A snap action breakers cost between $5 - $8 online, so I'm looking for cheaper alternatives.

Can anyone refer me to a cheap, equivalently sized fuse they've used? I'm looking at MAXI style fuses, so would products like this or this fit in the PDB?

[Mark McLeod]

...

Or email CTRE for advice on an alternative.

[MrForbes]

Perhaps the Maxi fuses do fit the 40 amp slots, and ATO fuses fit the 20/30 a slots?

I don't have any Maxi fuses handy, to check...but that's what it looks like to me.

[Mark McLeod]

Yea, I take back what I said about Maxi, they do look like a fit.
They match the dimensions of the 40a slot in the PDB.
I was mixing them up with the ATO fuses.

P.S.
Found supporting evidence in a snap action 40a breaker spec sheet quote
"Direct replacement for "MAXI" automotive style fuses"

So the question becomes how close to the 40a fuse maximum does your non-FRC robot run?
If it draws less than no problem. If it regularly draws over 40a, in a starting stall condition for instance, then it'll be a question of how often do they need replacement before the $6 breaker would be the better bargain.

[EricH]

On a related note, I've been on a hunt for the (really) old MAXI blocks that we used to use on the robots, or an equivalent. I'm talking those gold-plated ones with a clear cover--anybody remember those? KOP list from back that far doesn't seem to have the part number or anything similar.

[Greg Needel]

Originally Posted by EricH

On a related note, I've been on a hunt for the (really) old MAXI blocks that we used to use on the robots, or an equivalent. I'm talking those gold-plated ones with a clear cover--anybody remember those? KOP list from back that far doesn't seem to have the part number or anything similar.

If you just do a google search for Maxi fuse block, you will find equivalent ones. The ones we used to get were mainly used for car audio.

http://www.amazon.com/Stinger-SFPD4M...dp/B00Q50CSB8/

[evanperryg]

Originally Posted by EricH

On a related note, I've been on a hunt for the (really) old MAXI blocks that we used to use on the robots, or an equivalent. I'm talking those gold-plated ones with a clear cover--anybody remember those? KOP list from back that far doesn't seem to have the part number or anything similar.

We still have one sitting around. If you PM me an address, I'll talk to the mentors and see if we can ship it out to you!

[EricH]

Originally Posted by evanperryg

We still have one sitting around. If you PM me an address, I'll talk to the mentors and see if we can ship it out to you!

Thanks for the offer, but I'm pretty sure that wouldn't be feasible--this is for a non-FRC project, so we'd prefer to be able to track everything through our (more) standard sources. Though if it has a part number, that would help in tracking down similar products...

[GeeTwo]

Originally Posted by evanperryg

We still have one sitting around. If you PM me an address, I'll talk to the mentors and see if we can ship it out to you!

Originally Posted by EricH

Thanks for the offer, but I'm pretty sure that wouldn't be feasible--this is for a non-FRC project, so we'd prefer to be able to track everything through our (more) standard sources. Though if it has a part number, that would help in tracking down similar products...

Go back a few posts, and you can find a link!

Originally Posted by Greg Needel

If you just do a google search for Maxi fuse block, you will find equivalent ones. The ones we used to get were mainly used for car audio.

http://www.amazon.com/Stinger-SFPD4M...dp/B00Q50CSB8/

We used a Stinger maxi block for early iterations of our air cannon with the FRC-style snap breakers. The cannon outgrew four circuits, so we're now using an old PDB.

[Joe Ross]

Originally Posted by Mark McLeod

So the question becomes how close to the 40a fuse maximum does your non-FRC robot run?
If it draws less than no problem. If it regularly draws over 40a, in a starting stall condition for instance, then it'll be a question of how often do they need replacement before the $6 breaker would be the better bargain.

Based on some really quick research, a slow blow fuse will react slower then the snap action circuit breakers FRC uses, while normal blow fuses will react similarly.

[Al Skierkiewicz]

Guys,
The snap action breakers we use will sustain a 600% overload for a second or two and 300% for a while longer. When you are running CIMs the stall(start) current is 131 amps. If you use normal fuses, they will open with high current motors. While the fuses do have a spec that provides for currents in excess of their rated values, they do not survive three times their current ratings for very long and they are not repairable.
Bussman sheets can be found here...http://www.cooperindustries.com/cont...S_2049_MAX.pdf
I would suspect any house branded fuses like DB (linked above).

[GeeTwo]

Originally Posted by Al Skierkiewicz

Guys,
The snap action breakers we use will sustain a 600% overload for a second or two and 300% for a while longer. When you are running CIMs the stall(start) current is 131 amps. If you use normal fuses, they will open with high current motors. While the fuses do have a spec that provides for currents in excess of their rated values, they do not survive three times their current ratings for very long and they are not repairable.

I agree that the breakers are better all around. If you insist on fuses with large motors, be sure to ramp your voltage up to avoid that high inrush current. Of course, if the motor gets stuck, you will still draw that 131A when you get to full throttle. I would suggest monitoring the current to avoid this condition, but current-monitoring modules cost more than breakers.

[dradel]

Or visit the local car stereo shop or bestbuy. Best Buy will have them as part of an amplifier install kit.

[NWChen]

Thanks everyone for your help.