Thread: FP burning out
View Single Post
  #6   Spotlight this post!  
Unread 24-02-2004, 07:52
Joe Ross's Avatar Unsung FIRST Hero
Joe Ross Joe Ross is offline
Registered User
FRC #0330 (Beachbots)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1997
Location: Los Angeles, CA
Posts: 8,583
Joe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond repute
Re: FP burning out

Circuit breakers don't trip immediately when the current exceeds the limit. It takes time for the materials inside to heat up and open the circuit. The more current you put through it, the faster it heats up and the shorter time it takes to open the circuit.

If you look at the spec sheet for the 20 & 30 amp breakers, you'll see that it takes them between 3 and 6 seconds to trip at 200% of thier rated current. The 40 amp breaker would take even longer to trip. Thus, you were able to burn out the motor before the breaker tripped. That is one reason that FIRST requires a 30 amp breaker on the FP motors, rather then a 40.