Using 9 motors on the robot

[Itamar]

We need to connect 9 motors this year
and as you know there are only 8 40A outputs on the POWER DISTRIBUTION BOARD.
we wanted to know wether we can connect one victor to a 30A output.
We want to know if it will work and if it is legal.
if we cannot do this
we would love to get a suggestion how to connect the 9th motor.
Thank you.

[Jon236]

Look at the power requirements for the motors. Only the CIMS and the Fisher-Price motors require 40 Amp breakers; the rest can use the 30 Amp connections.

Good luck!

[Itamar]

Thank you for the quick answer!
We realy appreciate it.
Good luck to you too, and thank you once again.

[Chuck Glick]

Originally Posted by Itamar

We need to connect 9 motors this year
and as you know there are only 8 40A outputs on the POWER DISTRIBUTION BOARD.
we wanted to know wether we can connect one victor to a 30A output.
We want to know if it will work and if it is legal.
if we cannot do this
we would love to get a suggestion how to connect the 9th motor.
Thank you.

Take a look at the wiring rules. Depending on which motors you are using, they are required to be protected by a certain breaker.

<R46>
All active Power Distribution Board branch circuits shall be protected from overload with an appropriate value auto resetting Snap Action circuit breaker (from the KOP or identical equivalent).

A. Each speed controller branch circuit must be protected by one and only one 20-amp, 30-amp, or 40-amp circuit breaker on the Power Distribution Board. No other electrical load can be connected to the breaker supplying this circuit.

B. Each Spike relay module branch circuit must be protected with one and only one 20-amp circuit breaker on the Power Distribution Board. No other electrical load can be connected to the breaker supplying this circuit.

EDIT: Beat to response. Slow internet connection, I thank you.

[Joe Ross]

Originally Posted by Jon236

Look at the power requirements for the motors. Only the CIMS and the Fisher-Price motors require 40 Amp breakers; the rest can use the 30 Amp connections.

Are you sure about that? I looked at this year's rules, and could not find any requirement that a CIM or a fisher price require 40 amp breakers. Best I could tell, any motor can use any size circuit breaker, as long as the wire was sized properly.

For example, a fisher price motor can draw more then 40 amps at stall, but it will also burn itself up at stall. It may be wise to use a smaller breaker.

[Racer26]

Originally Posted by Joe Ross

Are you sure about that? I looked at this year's rules, and could not find any requirement that a CIM or a fisher price require 40 amp breakers. Best I could tell, any motor can use any size circuit breaker, as long as the wire was sized properly.

For example, a fisher price motor can draw more then 40 amps at stall, but it will also burn itself up at stall. It may be wise to use a smaller breaker.

You are indeed correct. The circuits on 20, 30, and 40 amp breakers must have appropriately sized wires, but there are not, as in the past, requirements that CIM's and FP's get 40A, and everything else is 20/30A.

[Jon Stratis]

Originally Posted by Jon236

Look at the power requirements for the motors. Only the CIMS and the Fisher-Price motors require 40 Amp breakers; the rest can use the 30 Amp connections.

Good luck!

Not quite true, this year.

<R55>
A. Each CIM motor and Fisher-Price motor must be connected to one and only one approved speed controller. These motors must not be connected to relay modules.

<R46>
A. Each speed controller branch circuit must be protected by one and only one 20-amp, 30-amp, or 40-amp circuit breaker on the Power Distribution Board. No other electrical load can be connected to the breaker supplying this circuit.

That being said... those two motors are the most likely to need a 40A breaker, as they can exceed 20/30A breakers safely - especially the CIM's. The other motors you can use smaller breakers without worrying too much about tripping them under normal, safe use.

[SuperBK]

Don't forget <R52> that says you can have a max of 5 CIM motors:

D. One, two, or three additional 2½” CIM motors (part #FR801-001 and/or M4-R0062-12) in addition to those provided in the KOP. This means that up to five, and no more, 2½” CIM motors can be used on the ROBOT.

So at least four motors are not CIMS?

[DarkFlame145]

Originally Posted by Itamar

We need to connect 9 motors this year
and as you know there are only 8 40A outputs on the POWER DISTRIBUTION BOARD.
we wanted to know wether we can connect one victor to a 30A output.
We want to know if it will work and if it is legal.
if we cannot do this
we would love to get a suggestion how to connect the 9th motor.
Thank you.

poor battery

[Jon Stratis]

Originally Posted by DarkFlame145

poor battery

The depends on how the motors are used. We have 8 motors on our robot this year (9 if you include the servo )

4 for driving, just like every other year
1 for a "ball magnet" like other teams have discussed and shown here, rolling continuously.
2 for a kicker - each one only needs to complete 1 full revolution out of the gear box per kick.
1 for a lifter which will only be used for 5-10 seconds at the end of the match.

So, a lot of motors to do a lot of different things... but overall not any more battery intensive than any other year.

[Al Skierkiewicz]

Everyone,
The electrical rules are written to coordinate breaker size to wire size only. The breakers are sized to protect the wiring and nothing else. If you put #18 wire with a 40 amp breaker and something shorts, then the wire will set itself on fire. 40 amp breakers get #12 or larger, 30 amp breakers get #14 or larger and 20 amp breakers get #18 or larger.
You can run a 20 amp breaker for a CIM motor if you so choose. Both the Jaguar and Victor can handle currents in excess of the stall current of the CIM motors. The circuit breakers used on FRC robots have trip characteristics that allow currents in excess of 600% of the trip point for a few seconds. Yes, that is 240 amps for a 40 amp breaker.
Although the rules allow it, I can't see any reason why you would want to run any motor except the CIM or Fisher Price motors with a 40 amp breaker. For a maximum motor count of 5 CIM and 2 FP, that is only 7 40 amp breakers.