I am replacing a robot with one that requires more power. I am using a transformer from a different source to power the new robot. The new robot will be fed from a 208Y120 transformer. I intend to use the neutral for control voltage to feed some DC supply's. The existing panel; however, already is being fed from another 120V source. Can these two neutrals be bonded, or do I need to isolate the two different sources within the panel?
2 different power sources
- Thread starter turkish
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HotConductor
Senior Member
- Location
- Philadelphia
Your question is ambiguous. Please provide more detail or upload a simple drawing.
HotConductor
Senior Member
- Location
- Philadelphia
Oh by the way...welcome to the land of mass confusion
The current electrical panel is being fed by a seperate 120vac source, connected to a service panel. My transformer will be powered by another area machine not connected to that service.
I would like to use the neutral provided with the secondary of the XFMR to power other devices that will be added to the current panel. What I am asking is if the two different sources of power in the panel can share each others neutral.
I cannot post an example drawing...this might have to wait until I get back to work tomorrow.
I would like to use the neutral provided with the secondary of the XFMR to power other devices that will be added to the current panel. What I am asking is if the two different sources of power in the panel can share each others neutral.
I cannot post an example drawing...this might have to wait until I get back to work tomorrow.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Best answer: no, do not interconnect the separate supplies.
- Location
- Lockport, IL
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- Semi-Retired Electrical Engineer
Current wants to return to its source. With a single phase, 120 volt circuit, the neutral is the wire that returns current to its source. If two circuits originating from two sources have their neutral wires connected, current won't know which way to go. :roll:
I can forsee two ways things could go bad. If the two sources are in perfect phase synchronization with each other, then they will act as though they are in parallel. That will double the voltage that is applied to each load, with destruction of the loads being a probable result. If the two sources are not in synch, at the moment they are both placed in service (i.e., when you turn on the second load), the result will be the same as placing any two power sources in parallel but out of synch: an explosion.
I can forsee two ways things could go bad. If the two sources are in perfect phase synchronization with each other, then they will act as though they are in parallel. That will double the voltage that is applied to each load, with destruction of the loads being a probable result. If the two sources are not in synch, at the moment they are both placed in service (i.e., when you turn on the second load), the result will be the same as placing any two power sources in parallel but out of synch: an explosion.
IMM_Doctor
Senior Member
Isolation is typical procedure
Isolation is typical procedure
When interfacing robots (seperate power and control voltages) to other equipment that has its own power and control sources, ISOLATION is common procedure.
Being that the robot and the equipment have thier own power, there is no reason to connect the power sources together, each can run stand-alone on it's own power.
Interfacing signals (communications and status) between the two can be acomplished via electro-mechanical realy, or opto-isolation relay based devices.
To send signals from the equipment to the robot, the equipment is the source voltage to the coils of the relays, and the robot would be the source voltage to the "DRY" or "Potential-Free" mechanical contacts on the relays.
To send signals from the robot to the equipment, revese the above scenario, where the robot neutral, and votage source powers the coils of the relays (or stimulates the opto-isolators), and the connectected equipment polls the "dry" contacts with its source voltage.
Isolation is typical procedure
When interfacing robots (seperate power and control voltages) to other equipment that has its own power and control sources, ISOLATION is common procedure.
Being that the robot and the equipment have thier own power, there is no reason to connect the power sources together, each can run stand-alone on it's own power.
Interfacing signals (communications and status) between the two can be acomplished via electro-mechanical realy, or opto-isolation relay based devices.
To send signals from the equipment to the robot, the equipment is the source voltage to the coils of the relays, and the robot would be the source voltage to the "DRY" or "Potential-Free" mechanical contacts on the relays.
To send signals from the robot to the equipment, revese the above scenario, where the robot neutral, and votage source powers the coils of the relays (or stimulates the opto-isolators), and the connectected equipment polls the "dry" contacts with its source voltage.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Sorry, Charlie, but that doesn't make sense. Both grounded conductors should be at the same potential. There should be no voltage doubling or explosions.
The concern would be a combination of an illegal paralleling of small conductors whose line conductors don't share the same cable/raceway.
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