Average Electrical Usage For A Multiple Residential Units Building

Thread Starter

Descent The Engineer

Joined Mar 13, 2020
3
Greetings Everyone

i am new here on the forum, i would like to get some insights from experienced/professional electrical engineers. So i have been given a task to investigate and give a report on the average Electrical Consumption of a Multi Rental Property with 282 residential apartments (1&2 bedrooms). there are a few boilers and heatpumps. They want a comprehensive report from the Incoming Power(Utility Company),boilers,apartments and common area lights.

How can i go about this using a 600V CLAMP Meter? I am a junior Electrician based in South Africa.

Thank You In Advance.
 

MaxHeadRoom

Joined Jul 18, 2013
20,407
For average consumption readings, usually a chart recorder is used.
You would need to ascertain what is the source of HVAC for the block, individual or central.
Other common area power consumption devices, lighting etc, any power used in parking area.
I suspect a clamp-on meter is not going to give you a 24hr average, and also seasonal consumption estimates.
I would imagine that without sophisticated equipment, an educated calculation could be made used a spread sheet using estimated loads.
I would think the average consumption should be spread over a years usage.
, Max.
 

Thread Starter

Descent The Engineer

Joined Mar 13, 2020
3
For average consumption readings, usually a chart recorder is used.
You would need to ascertain what is the source of HVAC for the block, individual or central.
Other common area power consumption devices, lighting etc, any power used in parking area.
I suspect a clamp-on meter is not going to give you a 24hr average, and also seasonal consumption estimates.
I would imagine that without sophisticated equipment, an educated calculation could be made used a spread sheet using estimated loads.
I would think the average consumption should be spread over a years usage.
, Max.
Thanks @MaxHeadRoom at the moment i don't have a chart recorder,only have a Clamp and Normal Multimeters. I had thought of measuring current during peak hours and calculate average using kinda ohms law?
 

Hymie

Joined Mar 30, 2018
797
Since they want a comprehensive report, I doubt some guesstimate will satisfy their requirements.

I would suggest you buy a few of these and attach them within known supply lines at strategic locations. They are capable of Wh energy measurements with a current of up to 100A. The advantage is that one version comes with an opening/closing transformer such that you will not need to break into a supply line to attach the current transformer.

I connected one within my home electrical supply, the Wh readings were within 0.5% of the utility meter readings.

https://www.ebay.co.uk/itm/100A-AC80-260V-LCD-Digital-Power-KWh-Watt-Meter-Volt-Amp-Voltmeter-Ammeter-Meter/223717612916?_trkparms=ispr=1&hash=item34169bdd74:m:mO5bGyp13cVbQW1sMnUgemQ&enc=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&checksum=22371761291654822185c6f24fb1b31e9e69090d9c50

Before embarking on such proposed measurements, I would recommend you advise the report recipient of the measurements you propose to make and ask whether they would meet their expected requirements for your report.
 
Last edited:

Thread Starter

Descent The Engineer

Joined Mar 13, 2020
3
Since they want a comprehensive report, I doubt some guesstimate will satisfy their requirements.

I would suggest you buy a few of these and attach them within known supply lines at strategic locations. They are capable of Wh energy measurements with a current of up to 100A. The advantage is that one version comes with an opening/closing transformer such that you will not need to break into a supply line to attach the current transformer.

I connected one within my home electrical supply, the Wh readings were within 0.5% of the utility meter readings.

https://www.ebay.co.uk/itm/100A-AC80-260V-LCD-Digital-Power-KWh-Watt-Meter-Volt-Amp-Voltmeter-Ammeter-Meter/223717612916?_trkparms=ispr=1&hash=item34169bdd74:m:mO5bGyp13cVbQW1sMnUgemQ&enc=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
/H8XvoT6NmftkA9+vxtmnWigisy9MvEBs3lwNGXT6uSOBO5CTBlApe5pQDG9oWaP2ZlI/ipMK6473OG/R4EgGMy7z4JAuZw==&checksum=22371761291654822185c6f24fb1b31e9e69090d9c50


Before embarking on such proposed measurements, I would recommend you advise the report recipient of the measurements you propose to make and ask whether they would meet their expected requirements for your report.
@Hymie thanks for the informative comment. I will definitely look into adding these to my instruments.
 

GetDeviceInfo

Joined Jun 7, 2009
1,702
I would think the power provider would have that info.

Bob
Yes, whoever supplies will know exactly what your consumption is. I have done many projects that increase demand on existing services. I request an annual demand report from the utility (free of charge) which logs current and power factor every hour for the year. I then determine based on that info, how additional loads ( if any) can be placed on the service. The municipal Inspectors often want to review the data and calcs before issuing permits.

I suggest the OP request a consumption report for the building, from the utility.

When designing electrical systems for such applications, there is a process of calculations that one goes through to determine ampacity and equipment ratings. Regardless of actual consumption, the result of the calculations is what determines the specs.
 
Last edited:

Glenn Holland

Joined Dec 26, 2014
705
Here in Northern California, PG&E has retrofitted most customers with "Smart Meters" that show a detailed graph of electric and gas consumption.

Are these apartments individually metered, but the common area has a separate meter? The meters for the apartments are considered private and confidential information that cannot be disclosed.
 

Janis59

Joined Aug 21, 2017
1,146
We use already ten or more years the radio-readable kWh measurers. I have such in my home. ALL is counted, ALL is calculated only I must do it is to pay. Why not to go this way.
 
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