Scotta9669
Member
I am wiring a PLC to VFD. When wiring to the 24 volt relays is white or black the common. I know this is a silly question but my mind is going a thousand miles an hour. I know on a switch Black is common but.....This is eluding me.
Relays
- Thread starter Scotta9669
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Typically, in 24V signaling field wiring, white is grounded (or negative for ungrounded DC), black is ungrounded (or positive).
I say typically because I don't know which, if any standard specifies such. More often than not in internal equipment wiring, it's the other way around (at least it was in my learning years :huh
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LLSolutions
Senior Member
- Location
- Long Island, NY
Where are the black and white sourced from? Is it ac or dc, if ac is one side of the transformer grounded? The color is meaningless.
just the cowboy
Inactive, Email Never Verified
- Location
- newburgh,ny
In controls
Black = line voltage
Red = hot control voltage
White = neutral
Green = ground
Blue = DC voltage ( I use a wire ends red + Blk - )
Try not to use word common sometime it is used for neutral
Black = line voltage
Red = hot control voltage
White = neutral
Green = ground
Blue = DC voltage ( I use a wire ends red + Blk - )
Try not to use word common sometime it is used for neutral
- Location
- Placerville, CA, USA
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- Retired PV System Designer
If you have single ended 120V AC and single ended 24V DC, they may share a commongrounded conductor which is not a neutral in either system. :angel:
This is for control panels and machinery under UL (508?) or NFPA 79... AFAIK.
Do you know of any standard for field wiring?
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