20 AMP power to motor controllers?

We have run out of 40AMP slots on our power distribution board, we were wondering if it’s possible to attach our other 2 motors to the 20AMP slots. The motor controllers are Victor 888’s. Is there any restriction on the size of the motor that can be connected?

You can hook up motor controllers to the PD board according to the game manual, but you cannot hook up the motor controllers to CIM motors. It’s under the 4.8: Power Distribution Section in the manual.

Why?

Point exactly to what rule says that.

Tables 4-2 and 4-4 show what can be hooked up to the right terminal. And I think CIM motors just need more amperage to operate.

I don’t think that is what that means.

Table 4-2: Branch Circuit Protection
Branch Circuit Circuit Breaker Value Quantity Allowed Per Breaker

Motor Controller Up to 40A 1

It can be run on any breaker up to 40A it does not have to though.

It’s very possible I’m wrong.

I’ve been unable to find a rule this year that specifies what motors are allowed to be connected through what breakers, but historically CIMs have required 40A breakers. This is due to it having a much higher stall current(in the 60A range if memory serves).

If you do decide to put a CIM on a 20A breaker, just remember that the breaker is there to protect the wire, but there’s still a chance of the high current burning out the wire before the breaker trips if the motor stalls. The AWG requirement in table 4-3 is just a minimum, so feel free to go higher in this case.

As far as I know, there hasn’t been a rule limiting certain motors to breaker sizes. The rules dictate the minimum wire gage that can be connected to a certain size breaker.
The CIM’s stall current is 133A at 12V.

The limiting factor regarding what motors can use what breakers is purely the fact that some combinations will not work well. As long as your wire gauge matches the breaker size, safety will not be an issue, as such, they appear to have decided not to create a rule that explicitly lists allowed or disallowed motor and breaker combinations.

My advice is to find the motor documentation and prioritize which motors get the 40 amp circuits based on that.

I agree that there are no rules forbidding connecting a CIM to a motor controller on a 20A breaker. However, unless you just happen to have a stack of CIMs in your inventory and no smaller motors, this is rather like getting a truck with a V8 engine then feeding it with a tiny fuel line. You’d be better off using a mini-CIM or other mid-size “unlimited” motor which will perform better at 20A.

+1. The extra power of the cim will be deadweight on a 20 amp breaker.
I would be concerned about running down the battery if I was using up every single 40 amp slot and still needed more cims.

Thanks for the correction on stall current. I was honestly just guessing on the number because I couldn’t easily look it up, but I knew it was well above 40A.

Anyway, I’ve been an inspector multiple times over the last 7 years I’ve been volunteering and have had to tell teams to change where CIM motors could be wires. This means it was on the inspection checklist, which means there was a rule for it. You may be true that there was no explicit list of what motors could be connected to what breakers, but there has been a rule in the past that said what breaker a CIM had to be on. I just woke up, so I’ll update this comment as soon as I’m coherent enough to go find a source.

We have run out of 40AMP slots on our power distribution board, we were wondering if it’s possible to attach our other 2 motors to the 20AMP slots. The motor controllers are Victor 888’s. Is there any restriction on the size of the motor that can be connected?

The smaller slots on the PDP can use 30A breakers

The SIMS come with a 14 gauge wire pigtail. Based on the wiring gauge table, does that limit it to a 30 amp breaker?

There is an exception to R38 that states : “Wires that are recommended by the device manufacturer or originally attached to legal devices are considered part of the device and by default legal. Such wires are exempt from R38.”

So the way I read the rule, a cim may be used in a 40A breaker, assuming all of the wire leading to the motor is 12AWG, not including the stock pigtails.

I don’t recall any such rule in the past and I see any item on the checklist from the past years that explicitly state that the cim must be on a 40 amp breaker. It does state that only snap action breakers up to 40A may be installed.