Backup power sources can be used to supplement utility power, notes Neil G Pansey. A backup power supply can take the form of an auxiliary generator, admits Neil G Pansey. With the risk of storms and voltage drops, users should review their power needs in advance, when time is on their side. Neil G Pansey notes that different types of users will have different requirements for residential, commercial or industrial applications. The backup power system will be sized according to each user's requirements.
Neil G Pansey notes that residential users should begin by considering their critical power needs and assess the loads of critical power consumers in amperes by preparing a power budget. The duration that each load would need to operate would also be needed to properly design a backup power system. Residential users should review key appliances, electronics, and medical devices needing electric power. Users with very young or old residents should be considered for unique requirements, notes Neil G Pansey. Residents should keep in mind that cost will be directly proportional to the number of amperes needed and hours of service. Residents, states Neil G Pansey should also have appropriate conductors needed to reach their loads from the location of their backup power system. Conductors should be sized appropriately for the load under service, and a backup generator should be kept outdoors to prevent harmful fumes from affecting persons. Neil G Pansey reminds residents to consider the level of noise the unit will create. Backup power systems should be tested regularly so that owners and users know how to operate them and to ensure the fuel; generator and conductors are kept in good operating condition. Both residential and commercial users should consider implementation of an automatic transfer switch for a subset of their critical power needs where no interruption can be tolerated.
Article 445 of the National Electric Code stipulates that generators should be of a type suitable for the locations in which they are installed. The ampacity of the conductors from the generator terminals to the first distribution devices containing overcurrent protection has to be at least 115 % of the nameplate current rating of the generator, notes Neil G Pansey. Live parts of generators operated at more than 50 volts to ground shall not be exposed to accidental contact where accessible to unqualified persons. Generators require disconnects, lockable in the open position, by means of which the generator and all protective devices and control apparatus are able to be disconnected entirely from the circuits supplied by the generator, except where the driving means for the generator can be readily shut down or the generator is not arranged to operate in parallel with another generator or other source of voltage. Neil G Pansey notes users and constructors should verify requirements in their jurisdictions.
Neil G Pansey notes that portable power systems can also be used for temporary power applications in construction and maintenance environments. Temporary electric power and lighting installations shall be permitted during the period of construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities. NEC Article 590 applies to temporary electric power and lighting installations, admits Neil G Pansey. The code requires that flexible cords and cables shall be protected from accidental damage, with sharp corners and projections avoided. Where passing through doorways or other pinch points, protection shall be provided to avoid damage. Many users will implement temporary power supplies for seasonal displays in public or private settings, notes Neil G Pansey. Equipment used on holiday displays should be analyzed for proper sizing and electrical safety.
All equipment grounding conductors shall be tested for continuity and shall be electrically continuous. Each receptacle and attachment plug shall be tested for correct attachment of the equipment grounding conductor, notes Neil G Pansey. The equipment grounding conductor shall be connected to its proper terminal. Testing of equipment shall be performed before first use on site, when there is evidence of damage, before equipment is returned to service following any repairs, and at intervals not exceeding 3 months, in order to be consistent with the code temporary power requirements, notes Neil G Pansey.