Wire Size for Protected Circuit

[rich2202]

We are powering 2 spike relays off one wago connection. the wago port has a 40 amp breaker, so per R49, we are using 12 AWG wire.

The Spikes will have 10 amp breakers. So, off the Spikes can we use 18 AWG wire, or does the entire circuit off the 40 amp wago have to be 12 AWG wire?

We are using the 40 amp wago because we ran out of connections on the smaller breakers, and the only size large breaker we have is 40 amps.

[Bob Steele]

First of all...
R37 All circuits, with the exceptions of those listed in R42 (RoboRio Power) and R44,(VRM Power) 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 4-10) not the M6 cap screws.

So I don't think you can connect two SPIKEs to the same PDP circuit.
You can ask Q and A if you wish.

Secondly, if you do find out it is legal:

R45 Only one wire shall be connected to each WAGO connector on the PDP.
If multi-point distribution of circuit power is needed (e.g. to provide
power to multiple PCMs and/or VRMs from one 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 WAGO connector to
power the circuit.

If you are using a 40A breaker to protect a circuit... all of the wiring would have to be a minimum of 12 gauge wire.

R49 All circuits shall be wired with appropriately sized insulated wire:
Table 4-3: Legal Wire Size
Application Minimum Wire Size
31 – 40A protected circuit 12 AWG (2.052mm)
21 – 30A protected circuit 14 AWG (1.628mm)
6 – 20A protected circuit
Between the PDP dedicated terminals and the VRM or PCM 18 AWG (1.024mm)
Compressor outputs from the PCM
Between the PDP and the roboRIO
VRM 2A circuits 22 AWG (0.645mm)
≤5A protected circuit
roboRIO PWM port outputs 26 AWG (0.404mm)

[rich2202]

Ok, I just realized that Spikes are "Relay Modules", so per R48 it can only go on a 20 AMP WAGO, and only one can be connected.

So let's assume one Custom Circuit on a 40 AMP WAGO: if the Custom Circuit has a 10 amp Fuse, can we use 18 AWG wire after the Fuse?

If a Relay Module is not controlling an Actuator does it still have to follow the Relay Module rules?

We would like to use multiple Spike Relays to control LED lights.

[Bob Steele]

I think that needs to be asked on Q and A or to the LRI directly.

As an inspector I would look favorably on it because the wiring after the spike would be protected by a 10 Amp fuse. The wiring to the Spike would have to be minimum 12 gauge

We should ask big Al.