Centroid Community CNC Support Forum

Took a new job so was put on back burner, But back on it, Finally. So going through got wired up to the actual servos. The machine has a transformer, pic attached. Not sure if it would be worth it to use. Unfortunately, in my knowledge 220v consists of 2 hot leads i assume 230v does as well but the wiring diagram doesn't make much sense. Can someone explain?

Ldguinn1 wrote: ↑Fri Dec 29, 2023 9:30 pm Took a new job so was put on back burner, But back on it, Finally. So going through got wired up to the actual servos. The machine has a transformer, pic attached. Not sure if it would be worth it to use. Unfortunately, in my knowledge 220v consists of 2 hot leads i assume 230v does as well but the wiring diagram doesn't make much sense. Can someone explain?
Screenshot 2023-12-28 192829.png

What is the plan for servos and servo drives?
What is the voltage of the spindle motor?
Marty

The only unusual thing I see in the transformer wiring is the R5 / FU8 connection on the primary side.

The R4 and T wires through FU3 and FU9 are in incoming supply, wired in parallel to two parallel primary windings.

On the right (secondary) side you have outgoing loads: R7 & T3 through FU7 to provide 12VAC to a work light; R2 and T2 through FU5 for probably an assortment of nominal 110VAC loads; and a separate pair of wires (also marked R2 and T2, in a departure from sensible practice) carrying 100VAC to a rectifier to make the bus voltage (ca. 140VDC) for the DC servo amplifiers.

Returning to the oddball R5/FU8 on the left side: it looks like they are using one of the two primary windings as an "autotransformer" (https://en.wikipedia.org/wiki/Autotransformer) to obtain ca. 210VAC for some smallish load, independent of the incoming service voltage. Presumably you could find out what that was for, by looking for (C) on page 4, line 7, of the wiring diagram.

Hey Marty,
I was thinking the transformer was needed, but if not then I will put it back with the dynapath.

actually going to reuse the servos from the machine, they are 40 in/lb 160v , Ordered a chinesium Spindle with BT 40 Spindle cartridge, Mount, drive, belt, but if I cant make it move in X,Y,or Z, thats kind of moot. Spindle motor is 380v3phase so going to have a VFD to supply that power.

The control on the machine is a Dynapath, that can be sold, Would love to purchase new/ reman servos but not in the budget at this time. So for now it is what it is.
I got my cables from centroid, and the motor power connectors on the cable, and the ones they sent were both males(lol) so trying to source the correct ones. also my servos have Red, black, grnd , then a smaller gauge red and black, but cant locate what the smaller wires are for. finding the servo wiring diagrams for old stuff is tough.

So far bench test seems ok, estop circuits work, encoders work, would love to test with motors but have to wait.

What Centroid control board are you using?

The smaller red and black wires in the motors would be for tachometers. Those are used with the old analog DC drives to provide motor speed feedback.

If you are still using those old analog drives (e.g. with an Oak unit), then you still need the tachometers.

If you are using an Allin1DC unit, then you do not need the tachometers and you can cut those wires short and cover them with heat shrink (or remove the tachometers altogether).

If you are using an Acorn board with new third-party step-and-direction DC drives, then you might or might not need the tachometers. See your drive documentation.

sorry I sprung for the allin1DC kit, cables, encoders, etc.. got a new cabinet, slowly coming together.

I'm probably in the wrong forum section.
I am a machinist by trade and teach machining at a technical college. I have access to machines but like my own projects.

With an Allin1DC, you do not need the tachometers or their wires.

I would keep the transformer, and either connect a Centroid CAPBRDLO rectifier assembly to the 100VAC secondary; or keep the original Chevalier rectifier assembly (bridge, cap, and resistor) likewise connected to that 100VAC secondary.

cncsnw wrote: ↑Sun Dec 31, 2023 10:49 pm With an Allin1DC, you do not need the tachometers or their wires.

I would keep the transformer, and either connect a Centroid CAPBRDLO rectifier assembly to the 100VAC secondary; or keep the original Chevalier rectifier assembly (bridge, cap, and resistor) likewise connected to that 100VAC secondary.

Marc,
Given his motors are 160VDC, would direct rectification of 120VAC be too much? I figure rectified would be 169VDC.
Marty

I am also wondering about his 380V spindle motor as well. Seems he would need a transformer?
Ldguinn1, are you in the US?

I am in the US. Was planning on using a VFD to supply 380v for spindle motor.