sub metering

[bobbymari]

Not very familiar with this concept. Was asked a question regairding submetering in apt buildings. Im assuming its a single meter feed to building where owner pays for electricity and wants to somehow calculate individual usage. Is anyone familiar with this ?

 

[27hillcrest]

We install Emon Demon kw meters for what you are asking. They come as a kit and the owner can use his billing kw rate to charge the tenant.

 

[bobbymari]

We install Emon Demon kw meters for what you are asking. They come as a kit and the owner can use his billing kw rate to charge the tenant.

wouldn't this require splitting all units electrically to get accurate readings of individual units? or do you just figure out which breakers control which units from main panel and install how ever many submeters necessary to main panel?

 

[jumper]

You need to check your local laws, sub metering is not allowed in many places.

 

[augie47]

You need to check your local laws, sub metering is not allowed in many places.

I strongly agree with jumper. I've seen a few messy situations where the contractor ended up in the middle.

The local POCO, and I'm told TVA, does not allow "re-billing" for electrical power. There may be some legal ways to skirt the rule. I do find it interesting that the latest Energy Codes being adopted in adjacent areas require metering of separate dwelling units. Not sure how the two forces will meet.

 

[hardworkingstiff]

We've run across this at marinas. The marinas are allowed to sub meter, but they are not allowed to charge more than they pay for the electricity. So what they do is charge the boat owners a % of the total bill that matches the % of electricity they used, plus a fee for gather the information and billing for it.

 

[readydave8]

You need to check your local laws, sub metering is not allowed in many places.

although it may be more common to find sub metering to be legal in most places, rebilling with a markup illegal in many places, rebilling at cost legal in many places, I know that's what you meant and I was expanding on your post.

 

[bobbymari]

You need to check your local laws, sub metering is not allowed in many places.

will do ,meeting with owner thursday to get an idea of what he wants done . will definetly check pocos and ahj requirements before hand. just wanted a little install insight before hand in case its allowed, Im sure we can figure it out if it is allowed and if not we move on to option 2 modular metering , chaching

 

[gvoltz@ems3.com]

Submetering

Submetering

If you are unfamiliar with the term submetering you should be talking to a (reputable) submetering company for your answers. Make sure they are familiar with local regulations and metering options. Another differentiating factor is that most submetering companies only do work on residential/multi-familty submetering. If your application is for a commercial property make sure your submetering company is familiar with the differences between residential rebilling v. commercial both from a regulatory standpoint and from the property owner/manager's standpoint. My company is (link removed please contact this poster by PM for more info).

 

[Open Neutral]

wouldn't this require splitting all units electrically to get accurate readings of individual units? or do you just figure out which breakers control which units from main panel and install how ever many submeters necessary to main panel?

Are there any {US} resi units built without a breaker panel for and only for that unit & in that unit? I could see an issue on old splits.

As for legalities, the one I have seen is an enormous NYC co-op complex [~1000 units, 5+ buildings...]. Built 1947, they have now submeters in each unit, adjacent to the panel. I assume the co-op splits the bill per the co-op board's authority.

 

[conmgt]

I looked into submetering for a multitenant property. I was surprised to find that the current transformers (CT) have low accuracy when measuring current below 20% of their rating. For example, if you use a 100A CT and the current is 10A, your reading may be high or low by a good margin. If you know that a tenant is likely to be using say 40A max, go with a 50A CT. You can also loop the wires being sampled around the CT and cuts the rating of the CT in half...or doubles it...not sure. You can even loop the CT lead wires through itself and make minor adjustments.
Check out CR Magnetics. I've bought some of their products.

 

[bobbymari]

Are there any {US} resi units built without a breaker panel for and only for that unit & in that unit? I could see an issue on old splits.

As for legalities, the one I have seen is an enormous NYC co-op complex [~1000 units, 5+ buildings...]. Built 1947, they have now submeters in each unit, adjacent to the panel. I assume the co-op splits the bill per the co-op board's authority.

absolutly there are tons of them. I've worked on numerous apt bldgs where there are NO subpanels at all in units. common load center in a hallway with branch circuits shared with multiple units , so answer is yes

 

[kwired]

You can measure and monitor all you want, but selling energy is a ballgame that you likely don't want to be involved in unless you are a power company, you will have rules and regulations to follow, taxes and other fees to collect and remit, maybe licensing is required, certification and calibration of metering equipment and possibly many other things I did not think of.

Charging a tenant a fee and not calling it an "energy" charge or referring to amounts of energy units used or anything similar on the billing statement gets around a lot of these problems.

 

[Open Neutral]

absolutly there are tons of them. I've worked on numerous apt bldgs where there are NO subpanels at all in units. common load center in a hallway with branch circuits shared with multiple units , so answer is yes

Silly me assumed the code/AHJ required same.