Power Supply wiring question

airscapes

I am replacing a working Rambo Board in a MakerGear M2 and the power supply has 3 sets of 24v outputs. Looks like the Duet 2 only has one VIN, anyone know if I can safely team all 3 output into one?
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fcwilt

@airscapes

Yes - just double, no triple check your work before applying power. It's really hard to get the "magic smoke" back in.

Frederick

airscapes

@fcwilt said in Power Supply wiring question:

@airscapes

Yes - just double, no triple check your work before applying power. It's really hard to get the "magic smoke" back in.

Frederick

As an auto mechanic from a former career, I learned that lesson early on..

alankilian

@airscapes said in Power Supply wiring question:

team all 3 output into one?

I think those three outputs are connected together at the power supply anyway, so you can just run one wire from any of the three terminals to the Duet board.

You can verify this by turning the power supply off and using a meter set on Ohms to check between the three terminals to see if they are near zero Ohms when nothing is connected to them.

airscapes

@alankilian Yes, another guy in the MG forum suggested that and they are all coming from a common location so I am good to do with one 14g pair.

achrn

@airscapes said in Power Supply wiring question:

so I am good to do with one 14g pair.

As long as the connectors are up to spec - I have sometimes assumed that power supplies have this arrangement (and a lot of them certainly do) because the connections are not rated to the full current the supply is capable of. (Though it might sometimes be simply because the power is needed in different places - e.g. multiple disk drives in a PC.)

The Duet end is will be OK, I can't make out (from the photo) what the PSU end is.

airscapes

@achrn said in Power Supply wiring question:

@airscapes said in Power Supply wiring question:

so I am good to do with one 14g pair.

As long as the connectors are up to spec - I have sometimes assumed that power supplies have this arrangement (and a lot of them certainly do) because the connections are not rated to the full current the supply is capable of. (Though it might sometimes be simply because the power is needed in different places - e.g. multiple disk drives in a PC.)

The Duet end is will be OK, I can't make out (from the photo) what the PSU end is.

On the rambo they connect to 3 seperate thing.. hotend, bed and logic. all positive and negative connection on the PS are the same. No resistance when checking between all positive and all negative terminals. I will probably just remove the all the wires from the PS and run a single 14 awg wire pair from all 3 connection at the PS to the Duet.

fcwilt

@airscapes

What gauge are the existing wires? Together they may already surpass 14 gauge.

Certainly nothing wrong with replacing them

Frederick

airscapes

@fcwilt Have not measured them. The PS is rated at 18.5 amps ane the wires look to be 18 at best but probably 16 since no one of the 3 things powered is going to pull 15 amps by itself.
According to this calc using 24v 3ft and 15amps I can use wither 16 or 14 gauge. Since I have 16 gauge J cord I will probably just go with that.
https://www.wirebarn.com/Wire-Calculator-_ep_41.html

fcwilt

@airscapes said in Power Supply wiring question:

@fcwilt Have not measured them. The PS is rated at 18.5 amps ane the wires look to be 18 at best but probably 16 since no one of the 3 things powered is going to pull 15 amps by itself.
According to this calc using 24v 3ft and 15amps I can use wither 16 or 14 gauge. Since I have 16 gauge J cord I will probably just go with that.
https://www.wirebarn.com/Wire-Calculator-_ep_41.html

One 14 has a cross section of appx 2.0 sq mm.

Two 16 would be appx 2.6.

Three 18 would be appx 2.4.

Frederick