Hank: Electrical Loads Evaluation - Condominium Bldg
Answer by: Hsiang (06/20/11)
Question: Hi Hsiang,
Our 70 unit condominium was built in 1970, and to my knowledge, designed with limited electrical capacity per unit. Now we are considering allowing unit owners to use air conditioning units that have previously been disallowed because of concern of the limited electrical capacity in the original design. There are two basic issues we are dealing with:
1) If the power will overload due to multiple use of air conditioners, wouldn't any circuit trip at the unit's breakers? Therefore other users are not affected. Would that be correct?
2) In evaluating the building's power capacity, we have the original plans. Is it okay to use an electrician or an electrical contractor to review the power capacity or is an architect or electrical engineer necessary?
Thanks for your answers.
Answer: Hi Hank,
Thank you for your question,
How did you guys managed all these years without air condition? Having grown up on tropical island I have learned to appreciate the beauty of air conditioning from a pretty early age and can hardly imagine life without it now.
Now if your condo building was built in the 70s, unless there were some special considerations, I can’t imagine that the use of air conditioning units was not taken into consideration in the initial electrical load calculation and design. The best way to confirm what is available would be to have an electrician take a look at both the unit panels and your main panels. Don’t rely on the drawings since often time what was built might not reflect what was drawn. Not to mention that it’s much easier to look at the panel instead of digging through the drawings.
To answer your first question; yes, an electrical overload will trip the unit’s breaker and will not affect other units in the same building. At the same time I would advise against testing the circuit this way as they were only meant to be backup purposes.
If you don’t have sufficient capacity then the electrician should also be able to tell you what your options are. Keep in mind that you cannot simply upgrade the electrical panels, you’ll also need to upgrade the wiring and may be even the conduits (the metal tube the wires run in) in order to up your capacity. Avoid conduits replacement as much as possible as that would require ripping up walls and would cost significantly more to do then simply replacing wires.
Hope this helps, have a cool summer!
_Hsiang Lin, AIA LEED AP
Thank you for your question,
How did you guys managed all these years without air condition? Having grown up on tropical island I have learned to appreciate the beauty of air conditioning from a pretty early age and can hardly imagine life without it now.
Now if your condo building was built in the 70s, unless there were some special considerations, I can’t imagine that the use of air conditioning units was not taken into consideration in the initial electrical load calculation and design. The best way to confirm what is available would be to have an electrician take a look at both the unit panels and your main panels. Don’t rely on the drawings since often time what was built might not reflect what was drawn. Not to mention that it’s much easier to look at the panel instead of digging through the drawings.
To answer your first question; yes, an electrical overload will trip the unit’s breaker and will not affect other units in the same building. At the same time I would advise against testing the circuit this way as they were only meant to be backup purposes.
If you don’t have sufficient capacity then the electrician should also be able to tell you what your options are. Keep in mind that you cannot simply upgrade the electrical panels, you’ll also need to upgrade the wiring and may be even the conduits (the metal tube the wires run in) in order to up your capacity. Avoid conduits replacement as much as possible as that would require ripping up walls and would cost significantly more to do then simply replacing wires.
Hope this helps, have a cool summer!
_Hsiang Lin, AIA LEED AP
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About Us...
Guido Tenaglia
LEED AP
LEED AP
Guido Tenaglia has over 15 years of experience in the architectural profession and has worked on a variety of projects including corporate, retail & professional office installations.He received a Master of Science in Architectural Science from the University of Buenos Aires School of Architecture & Urbanism. Also had Post-Graduate courses in Architecture & History in the Universita IUAV of Venezia Italy.Mr. Tenaglia is Leed Accredited Professional ,meaning that he has demonstrated a comprehensive understanding of green building practices.Also he is a member of the Buenos Aires Board of Architects(CPAU).
Hsiang Lin
AIA, LEED AP
AIA, LEED AP
Hsiang Lin is a registered architect in the State of New York with 12 years of experiences and holds the NCARB (National Council of Architectural Registration Boards)certificate, which signifies that he has met the profession's most objective standards of competence.He received a Bachelor of Architecture from Syracuse University and graduated with the Dean's Citation Honor and is a LEED accredited professional from USGBC (United State Green Building Council).