Taking the CNC Plunge

[TomS]

No worries. I'm pretty straight with standard residential wiring having been a general contractor for the past 25 years but I am also less comfortable with electronics or high voltage wiring.

Sorry if I am presenting what you may already know but I want to make sure we are on the same page.

Standard residential wiring is the US is typically as follows:

Three wires into the main service from the Utility company: Line 1 (110v), Line 2 (110v), Ground

Typical home circuit.
110vac (black wire = Line 1 (hot), (white wire = neutral) ( green or bare wire = ground). 110v is measured across the hot and neutral.
220v (3-wire), (black wire = Line 1 (hot), (Red wire = Line 2 (hot) ( green or bare wire = ground). 220v is measured across Line 1 & Line 2, or 110v from line 1 or 2 to ground.
220v (4-wire), (black wire = Line 1 (hot), (Red wire = Line 2 (hot) (white wire = neutral) ( green or bare wire = ground)

Where I am getting confused is when you say you have 220v to the SSR on a single wire? On your power supplies, for 220v, terminals L & N would connect to Line 1 and Line 2 . There would be no neutral, just ground.

Jay

I'll take a close up picture of the 220v circuit and post it. Maybe that will clear it up.

Tom S

 

[jbolt]

Tom, it occurred to me that the 220v side may be for 220v/50hz single wire which is a European standard. Are you sure you can run the power supply on US 220v/60hz?

Jay

 

[TomS]

I'll take a close up picture of the 220v circuit and post it. Maybe that will clear it up.

Tom S

Here are some close up pictures of the relay and power supply wiring. I was incorrect when I said I had 220v across the relay when it was energized with 5v DC (actually 4.06v DC). Don't know where that came from. The relay doesn't appear to be closing on the AC side because I don't have continuity through the two terminals when the relay is energized.

The 5v dc control signal to the relay is fed by the transformer that is located to the right of the fuse block. I have assumed that the red wire is + and the black wire -. When I power up the transformer the red indicator light on the relay lights up. That leads me to believe the transformer is wired to the relay correctly.

The black wire connected to the #1 relay terminal and the white wire connected to the junction block left of the fuse block is my 220v input into the enclosure. The green ground wire is not shown but it is connected to the grounding lug. What is odd is I have 110-120 volts measured at the power supply line/load and neutral terminals to ground. I can understand the neutral terminal showing voltage because of the way I have the circuit wired but I don't understand why I'm getting a voltage reading between the line/load terminal and ground.

This picture shows the 220v wiring to one of the power supplies. The black wire is load/line and comes from the fuse block. The white wire is what I call neutral and comes from the junction block in the first picture. The green/ground wire goes to the grounding lug.

So I'm at a loss on how to wire this circuit. Any direction you can give me is appreciated.

Tom S

 

[JimDawson]

I can understand the neutral terminal showing voltage because of the way I have the circuit wired but I don't understand why I'm getting a voltage reading between the line/load terminal and ground.

Without a fuse in the holder I would expect to see voltage to ground on both terminals because the Triac in the relay leaks a very small amount of current with 220 volt power connected.

The relay doesn't appear to be closing on the AC side because I don't have continuity through the two terminals when the relay is energized.

Without the 220v power connected, and a load on the relay you won't see continuity on the relay, it requires a current flow to turn on. Just checking with an ohmmeter across the unconnected terminals won't tell you anything. The ohmmeter won't draw enough current to turn on the Triac.
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[TomS]

Without a fuse in the holder I would expect to see voltage to ground on both terminals because the Triac in the relay leaks a very small amount of current with 220 volt power connected.



Without the 220v power connected, and a load on the relay you won't see continuity on the relay, it requires a current flow to turn on. Just checking with an ohmmeter across the unconnected terminals won't tell you anything. The ohmmeter won't draw enough current to turn on the Triac.
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Thanks for the clarification. Still trying to figure out how to wire this circuit. The way it's currently wired I'm not getting 220v out of the relay.

Tom S

 

[JimDawson]

Are you measuring to ground or what you are calling neutral? I would expect 120 to ground, and 240 to neutral assuming the ''neutral'' is actually the other leg of the 240.

 

[TomS]

Are you measuring to ground or what you are calling neutral? I would expect 120 to ground, and 240 to neutral assuming the ''neutral'' is actually the other leg of the 240.

I'm calling the white wire neutral. I get 220v measuring voltage between the black and white wires and 120v when measuring between each wire and ground. Does this make sense? I'm by no means an electrician.

Tom S

 

[JimDawson]

Yup, that makes sense. That relay won't turn on until you put a load on it, in other words put a power supply fuse in and try it. SSRs are a little strange in the way they work relative to a electro-mechanical relay.

I think I read earlier in this thread that you are supplying this panel with both 240 and 120 on separate circuits. Using white for one leg of the 240 could be a bit confusing. Normally 240 would be black and red. White would normally be the neutral in the 120 volt circuit.

 

[TomS]

Yup, that makes sense. That relay won't turn on until you put a load on it, in other words put a power supply fuse in and try it. SSRs are a little strange in the way they work relative to a electro-mechanical relay.

I think I read earlier in this thread that you are supplying this panel with both 240 and 120 on separate circuits. Using white for one leg of the 240 could be a bit confusing. Normally 240 would be black and red. White would normally be the neutral in the 120 volt circuit.

I hear you about the red wire. I had a short 10ga 120v extension cord that I used for the 220v power supply. That's how I ended up with a white wire in the circuit.

Thanks to you and jbolt for helping me through this. Tomorrow I'll power up the system and see if the motors turn.

Tom S

 

[jbolt]

Jim,

Are you familiar with these types of power supplies and the 110v / 220v switch? I'm just wondering if they will accept how we (USA) wire 220v vs the European system or maybe they accept both?

Jay