Maxi Block Issue

[Paul Copioli]

You can use a 40, 30, or 20 amp breaker for the van door motor (or Fisher-Price, or CIM). The breaker is meant to protect so as long as the breaker is BELOW the stall current, you are legal per the rules. For example, you can't use a 40 amp breaker on a motor with a 20 amp stall current, but you can use a 20 amp breaker on a motor with a 40 amp stall current.

The main reason you want to do this is weight. Per the FRC electrical wiring rules, you must use certain gauge wire for certain breaker sizes. If you are using a Fisher-Price motor, but design your mechanism to only need a continuous current of 24 amps (for example), then you only need a 30 amp breaker instead of a 40 amp breaker. In this case you save weight in two ways: (1) you do not have to use the maxi block (it is heavy) and (2) you can down size your wire diameter (more weight). This is a key weight savings opportunity that many teams miss. We take advantage of the fuse sizing in as many places as we can.

-Paul