Managing Electrical Power
By Peter Varsalona, PE, CEM, CBCP
Principal & Vice President, RAND Engineering & Architecture, DPC
Cooperative and condominium boards must regularly balance the requests of individual residents with the interests of the building at large. A typical example is when residents ask for more electrical power to their apartments so they can run heavy-duty appliances, central air conditioning systems, or extensive lighting systems. Most buildings have a limited electrical capacity, so boards can’t accommodate every request for additional power. This leaves boards with the option of either undertaking an often expensive electrical upgrade or managing the spare electrical capacity within the existing system.
Most newer buildings were designed with electrical capacity distributed fairly equally among apartments, based on unit size. A studio or one-bedroom apartment, for example, may have 40 amperes of capacity, a two-bedroom apartment 60 amps, and units with three bedrooms or larger 80 amps or more. For many residents, however, the existing power supply to their apartments is inadequate for their needs. Heavy-duty appliances, such as air conditioners, electric dryers, and electric stoves and ovens, for example, and electric heating and central air conditioning, all require more electrical capacity than the standard amount provided in most systems.
Many boards routinely accommodate a resident’s request for increased capacity, usually on a first-come, first-serve basis, as long as the building has extra capacity to give. But as more and more residents make similar requests, boards are forced to turn down later ones because the building’s electrical system eventually becomes tapped out. This puts the board in the awkward position of having granted extra capacity to some residents (some of whom may have received more than they needed, sometimes from a previous board) while shutting others out.
Surveying the System
Property managers and board members can take measures to improve the distribution of their building’s electrical system and provide power to all residents fairly. The first step is to determine whether the building’s electrical system can sufficiently handle the existing demands placed upon it as well as any reasonably anticipated future demands. This requires engaging a professional engineer to conduct a survey of the building’s load capacity and power usage, including the supply to each apartment. The survey should answer the following questions:
- What is the existing electrical capacity for each apartment?
- Which apartments have been given extra capacity?
- How much spare capacity remains, if any?
- How much spare capacity can potentially be given to residents who request more?
- What are the expected future demands for increased electrical power?
- Based on present capacity and anticipated future needs, does the building have enough main power or does it need to request more from the local utility?
Load Calculations
To determine the electrical capacity required for each apartment, the engineer calculates the power load based on square footage and expected usage in accordance with the National Electrical Code (NEC). Three types of electrical loads are typically calculated: a lighting and general receptacle load (for residences, 3 watts/sq. ft.), an appliance load (usually 1,500 watts per appliance circuit), and an air-conditioning load (the minimum circuit capacity is provided by the manufacturer). If residents plan to add heavy-duty appliances or extra lighting that will increase their electrical needs, then that anticipated power usage should be included in the calculation.
Most buildings have a limited electrical capacity, so boards can’t accommodate every request for additional power.
The electrical usage and capacity are calculated for each apartment and then added to the building’s other public light and power needs, such as hallway and stairwell lights, elevators, boilers, compactors, etc., to determine the building’s total power requirements. The NEC permits the use of demand factor percentages (the anticipated amount of simultaneous power usage among residents at any one particular time) in calculating the overall power requirements for the building. The higher the demand load, the less “spare” power available.
If the present or expected future power demands outstrip the building’s existing electrical capacity, then the board will need to request an increase in the power supply to the building via the local utility. The building’s engineer must prepare a “load” letter delineating the proposed increases in the loads throughout the building subsequent to the service upgrade. The utility will review the request for additional power (or service upgrade) and may decline the request if the increased demand is insignificant or limited. The costs for a building-wide upgrade are usually shared equally among residents because all will benefit from the increase in available power.
When There’s Little to Spare
In some buildings with little capacity to spare, boards may decide not to upgrade their electrical systems for budgetary or other reasons. In this case, they must carefully manage the distribution of the existing electrical capacity. To prevent a few residents from grabbing the lion’s share of the spare capacity, all requests for more power to individual apartments must be accompanied by the resident’s design plans and a load calculation, which the resident’s designer usually provides. The building’s engineer should review the plans and load calculation of the apartment to determine if the amount of power requested is necessary, how much capacity the building can spare, and what new equipment would be required to accommodate it.
Prepare for future upgrades by establishing a “rainy day” electrical budget funded by residents.
If the board agrees to the request, the resident hires his or her own contractor to perform the upgrade, which typically involves installing new risers from the main service switches in the basement to the panel box in the apartment. The electrical components inside the individual apartment, such as circuits, circuit breakers, and outlets, may also need to be upgraded, which would be the resident’s responsibility as well.
Most boards will grant reasonable requests for more capacity to accommodate extra air conditioners, higher-energy appliances, or new lighting. Extraordinary requests, however, such as for rarely needed heavy-duty three-phase power, would likely be denied. A board must not be afraid to deny or scale back unreasonable requests for unnecessary capacity in the interest of preserving the building’s limited electrical resources.
Preparing for Future Upgrades
Even buildings with a surplus of electrical power will eventually reach a point of limited capacity as boards grant available power to more and more residents. One way for boards to prepare for this contingency is to establish a “rainy day” electrical budget funded by selling spare capacity to residents who request it. In this way, as capacity is distributed the board is putting away funds for a building-wide electrical upgrade in the future. For example, if the engineer’s survey has determined the building has 500 amperes of extra capacity and projected that an electrical upgrade would cost $100,000, the board would charge $200 for every extra ampere of capacity granted. When the capacity is close to depletion, the board will have saved the accrued funds for undertaking the necessary service upgrade.
Boards and property managers need to help residents understand that their building does not have unlimited electrical resources. Rationing capacity and requiring residents to pay for their share of it may seem unduly strict, but it’s the only way to make sure that electrical power is fairly distributed to all residents while keeping the building running smoothly.