Is this allowed? One breaker, one wire, all motors limited by spark max current limiting

We have some complicated wiring to do. An idea someone had since we’re using all spark maxes is using one low gauge wire maybe 8-10 with a 40amp breaker on the pdp and routing it to a terminal block which goes to 4 spark maxes with current limiting of 10amps each powering 4 neo 550s. Is this allowed, or safe, and even possible?

Have you looked at R621?

No. You’ll want to review R610 - 1 breaker per circuit.


No, maybe, yes.


Please don’t

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9 ROBOT Construction Rules V3 96 of 142

*R610 1 breaker per circuit. All circuits, with the exceptions of those listed in R615 and R617, must connect to, and have power sourced solely by, a single protected 12VDC WAGO connector pair (i.e. the load terminals, as shown in Figure 9-10) of the PDP/PDH, not the M6 cap screws.

1 motor controller per circuit.


We got this idea from
R618 *Use PDP/PDH terminals as designed. Only 1 wire shall be connected to each terminal on the
If multi-point distribution of circuit power is needed (e.g. to provide power to
multiple PCMs and/or VRMs from 1 20A circuit), then all incoming wires may be
appropriately spliced into the main lead (e.g. using an insulated terminal block,
crimped splice or soldered wire splice), and the single main lead inserted into the
terminal to power the circuit.

are we interpreting it wrong

That rule really applies to custom circuits that have lower requirements. You can power several lines of LED’s off the same terminal block, for example. The rules around actuator control and power are much more strict.


Also, as @Joe_Ross pointed out, R621 applies here and is MUCH more applicable than R610.

*Protect circuits with appropriate circuit breakers. Each branch circuit must be protected by 1 and only 1 circuit breaker or fuse on the PDP/PDH per Table 9-3. No other electrical load can be connected to the breaker or fuse supplying this circuit.

The very first line of that table reads:
Branch Circuit | Circuit Breaker Value | Quantity Allowed Per Breaker
Motor Controller | Up to 40A | 1

One breaker, one motor controller, no exceptions.

And, on top of that, R625 would also apply (this terminal block would be altering a power pathway between the PDP and the motor controllers).

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See This Table:

Table 9-3 Branch circuit protection requirements