Condo/Duplex shared well. Electrical inspector wants separate meter.
Working on a project for Habitat for Humanity that is two attached homes that will share both the septic and the well. The original plan was to bring the well water into the back dwelling, install one pressure tank and then continue the water to the front dwelling. The power for the well will come off the panel from the back dwelling. We would independently meter the power consumption and split the cost between the two dwellings. Both dwellings will have solar, so we don’t expect there to be any cost to run the pump.
The electrical inspector is requiring us to bring in a separate service with its own meter. His concern is that if the back dwelling has it service shut off the front dwelling will lose its water. While this is possible, I am not sure it’s an electrical code issue.
It’s a considerable added expense to the project and the homeowners will now have to pay the meter charge and for the power for the pump as this will not be tied into the solar panels.
Is the inspector correct and this is a requirement of the electrical code?
Thanks for your help on this.
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Replies
eust2023,
I'm sorry I don't have an answer to your question, however I would suggest you might want to follow his advice anyway.
I've been involved in several similar social housing projects and I think one weakness in their planning is they assume the same reciprocal common interests and relationships that are present during the design and building will persist over time.
There is a temptation to say this is a Habitat project, so shared or common elements which wouldn't be included in similar ones make sense here - and I think that's a mistake. It makes the units much harder to adapt over time - whether those changes are physical ones, or in the nature of the tenure of the occupants.
I would separate both the plumbing and electrical as much as possible, running dual systems from the well, and not run anything that services one unit through the other.
I'm not aware of anything in the electrical code that would require anything like this. The issue you might have is arguing with the inspector over this.
There is a simple way to make the inspector happy without breaking the bank. I assume your well pump will use the standard 15 or 20 amp 240 volt circuit. You can get 30A double pole manual transfer switches. I would put one of those at or near the well's pressure switch, right before the manual shutoff switch for the well. Supply the two inputs to the manual transfer switch with circuits fed from both unit's panels. In this way, if the service to either unit is ever shut off, you can just switch the transfer switch over to power the well pump from the other unit. This will add the cost of the transfer switch (probably under $100), some wire, a second double pole breaker, and some electrician time. This might be less hassle than dealing with the inspector.
I would consider adding a check valves to supply each unit from the common supply, to help limit risks of contamination. BE SURE you have a vacuum breaker on any outdoor hose connections too!
Bill
Bill
Thanks for the reply. We did discuss this with inspector. His concern which might be a code issue is that if the fire department entered the building with the power off. The well pump circuit could still be live from the other unit.
You'd have that same issue with a seperate meter for the pump...
It is possible to set things up with solenoid valves and relay logic to allow one pump to serve two seperate "systems" (pressure tanks and pressure switches), but it's overly complex I think for something like this. If you can't use the transfer switch, I'd go with the seperate meter.
I'm also with Malcolm to try to keep things as seperate as possible between the two units, since you don't know what might happen down the road. I can understand the desire to try to share some common infrastructure to share costs, but without some mechanism to deal with this (similar to HOAs and condo associations), you are potentially stting things up for problems down the road when things inevitably break and someone has to pay to repair them.
Bill
Bill
You are right about that. Not sure if I want to point this out to the inspector or not.
Thanks
eust2023,
I understand the financial constraints you are facing, and that you don't want to backtrack at this point. But now you understand the safety concerns, how are you going to address them to protect the firefighters, and other trades who may work on the house in the future?
I'm with Malcolm on this.
For a semi detached setup, each should have its own dedicated services, this will greatly simplify the life of the people living there in the long run.
Our local rules only allow for shared services for an ADU where the two buildings are on the same title.
Shared pumps does exist in cottage country north of me, there it is on its own meter/panel.
if there were a main exterioor panel with interior sub-panels for each dwelling, then that might satisfy requirements. it would be similar to "house panel" with tenant sub-meters that is used in multi-family dwellings. still more expensive than your solution since you need an exterior enclosed main panel but still cheaper than separate service.
Consider spending the money for separate systems now Yes it will cost 20K more now but when the well has a problem as it certainly will one day. The finger pointing begins about who pays how much who uses too much water and who broke the well. The list of things to argue about when you share a common wall is long and now your adding money and bathroom habits to the list. Who flushed what that clogged the septic? You use too much water and wasting the solar credits that belong to me and burning out the well.
It seemed to me we don’t like to think about it but Habitat houses well get sold one day and all the money saved will be lost in reduced sale price due all the shared stuff making it hard to sell.
I think the inspector’s complaint is a health concern if your neighbor fails to pay his bills and gets disconnected due to no fault of your own you have no safe water and own a building that can not be legally occupied.
Walta
Walta,
The first side by side duplex I built had problems with common elements. Everything was separate, but the lot surrounding the units was registered as common property. Almost immediately there was conflict over where they could fence, and who could use which part of the lot for what. The next two I built I had the lot divided into areas of exclusive use.
Thanks for all the replies. The two units are attached and will have a condo agreement of some kind. I do agree that it makes sense to try to fully separate the utilities for the units but at this point it's not going to happen.
Is it a shallow well with the pump inside the building? Would it be easier just to add a second pump?
Two pumps greatly complicates things unless you also have two drop pipes in the well.
You CAN use one pump and two pressure switches though, by setting up some solenoid valves between the pump and each unit's pressure tank. The way this works is that each unit has a pressure tank, and a pressure switch. The pressure switch for each unit opens the solenoid valve between the outlet of the pump and that unit's pressure tank, and also runs the coil of a relay that will energize the pump. This means either unit can turn on the pump, and will open the correct solenoid valve so that the pump serves the right unit. You NEED A THIRD PRESSURE SWITCH with this system that is BEFORE the two solenoid valves. This becomes the "overpressure switch" and you wire this to cut the pump out in case the solenoid valves don't open when one of the units calls for the pump. With a little ingenuity, you can use some extra contacts on the pump activation relays to "lock out" the other unit, to ensure that the pump ONLY pumps to the unit that calls for water, which means you never have a situation where the pump is trying to supply both units at the same time. This can also be used to connect the pump to the unit calling for water, so that the unit that needs water is the unit that supplies power to run the pump, and gets billed for that power.
This gets a bit more complex, but it is perfectly workable. The downside is the pump service techs probably won't understand what's going on, so they'll be nervous working on the system.
Bill
Bill
This system will work but the complexity will at some point lead to the well shutting down and the service tech ripping it all out and starting over with a system they understand. Thanks for your input.
DCcontrian
The pump is a submersible. The best answer is to just drill a second well, but the costs are way beyond our budget.
I cannot understand a fire issue since I cannot see a situation where there was a fire in attached dwellings and the fire department did not shut off power to both dwellings. I think there may be a code issue with wires from two breakers on two different services in the same box. Similarly what if the well needs service?
I could envision a circuit where with two apartments two pressure tanks, two pressure switches, when your tank goes low, it takes power from your circuit and fires the pump, with an external shut off to allow service. If either party said 'ha ha I'm shutting off my breaker and stealing your power' they would only have water when your system called for water. A relay could be installed in the exterior shut off box that prevented both systems calling water the same time[and the possibility of a future electrician miswiring to create a phase to phase short]
This feels to me like the kind of thing a well company or septic company would be familiar with the implementation and permitting of
I refuse to believe this is the first time in the history of the world that this issue has come up. City water is far from universal
And think of the big red labels on solar installations, such warnings are pretty straighforward