Supplying Residential Load from an Industrial Substation 3

[kingbambina]

Greetings,

We have a substation that feeds a fuel loading plant and there is an on-going project to build houses near the plant and it was proposed to supply this project from the same substation. Is there any standard that prohibits a substation from feeding industrial and residential loads at the same time?

Thanks in advance.

 

[che12345]

Dear Mr. Majed12345 (Electrical)(OP)7 Mar 22 08:09
"...We have a substation that feeds a fuel loading plant and ..... it was proposed to supply this project from the same substation. Is there any standard that prohibits a substation from feeding industrial and residential loads at the same time?..."[/color].
It depends on :
a) if the sub-station is yours, you can do whatever you like,
b) if the sub-station is under key and lock by the supply utility, you would have to approach the utility. The utility has the final say,
c) in same cases, the utility [tariff] differs between "industry" and "residential/domestic" . Under such circumstances, a different set of kWh meter for two different consumers respectively.
Che Kuan Yau (Singapore)

 

[jghrist]

Are you the utility? Do you own the substation?

Often, industries will use resistance grounding on medium voltage to limit ground faults. If this is the case, typical (North American) residential distribution (with single phase transformers connected phase to neutral) would not be possible. You could connect all the distribution transformers phase to phase, however.

 

[cranky108]

About the only reasons a utility would not use the same substation to feed both types of loads is because of contract, certified area, or if the combined loads is beyond the capability of the substation (in most cases the substation equipment will likely be upgraded).

Why do you feel the utility should not serve both types of loads from the same substation?

 

[jraef]

You might also end up with higher than typical available fault current values at the residential installations, forcing the houses to have more expensive panelboards for distribution.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[kingbambina]

Thanks all. The substation is ours and inside our plant. The housing projects is nearby the plant since it's designated for our employees. And the reason for connecting from the same substation is the ease of access and logistics since it's ours.

 

[jghrist]

If the substation is yours, then the revenue metering will cover all of the transformer load and probably transformer losses. This would complicate things a lot if the utility is going to serve the residential loads. If the plant is going to furnish power for the employee residences without charge, I don't see a problem. If you are going to meter and bill the employees, then you may have a contractual problem with the utility. Resale of energy may not be allowed.

 

[cranky108]

I don't see that the residential installations would necessarily have a larger fault current. The distribution transformer impedance usually sets the low side fault current, and because of grounding issues, as well as losses, I would expect the residential would be served by a distribution transformer close to the homes, and not by the substation directly.
I would also expect the plants internal distribution voltage would be too high for residential loads, and so would require a step-down.

 

[bacon4life]

It is common for remote hydro generators to supply power to employee housing. Power supplied to employee housing has to be correctly accounted for on the USA Energy Information Administration (EIA-861) data requests. I am not sure which other industries may have similar reporting requirements.

In my area landlords can split the electricity bill among tenants, but they cannot charge more than the total bill. In other words, the restriction is on markup rather than resale. I assume this varies widely be region.

In the USA, the value of "free" energy provided to employees might be taxed as fringe benefit.

 

[cranky108]

Our remote hydro generators do supply several caretakers houses, but those are owned by the company. There are also a few communication shacks, and tool sheds that are also supplied, as well as 'street lights' around the plants.
They all have meters on them. But I'm unsure of the billing.
But they all are served off a stepdown transformer, as the generator 7kV is too high for most loads.

 

[Fischstabchen]

I think this is more of a question of not can you but should you. The part that would concern me is that for a facility to have its own substation, it has to have a pretty involved process to justify the expense. Does an industrial facility want to deal with a third party who can impact their equipment? Does an industrial facility want to have to deal with a third party when performing maintenance or replacing equipment? I don't know how happy residential customers would be if they were without power for a few days. As an industrial facility, are you willing to provide the same availability to a third party as they would expect from a utility? If I was a plant manager, I would have strong reservations with wrapping a third party into my shit when I have a million other fire to put out.

 

[davidbeach]

Geesh. The OP does say that the residential load is associated with the plant.

I could see it being a win/win. Put the residential load on a separate transformer, but large enough so that either transformer could supply the bulk of the combined load. That way the load gets served at less cost than bringing in an additional transmission source and the redundancy, and thus the resiliency, of the plant source is increased.

I’ll see your silver lining and raise you two black clouds. - Protection Operations