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Receptacles

Every receptacle on a branch circuit must have an ampere rating not less than that of the branch circuit 210.221(B)(1). This might seem counterintuitive, but the rationale is that you want the circuit to open via breaker trip rather than via receptacle melt. If the breaker limits the current to the receptacle to a level below what the receptacle can handle, the receptacle won’t melt from overload.

If a branch circuit has more than one receptacle, apply Table 210.21(B)(2) to determine maximum load and Table 210.21(B)(3) to determine receptacle ratings.

However, these requirements make several assumptions that may be false for your particular installation. Your code-compliant installation may become a nuisance-trip situation or even a fire hazard.

For example, many older offices contain birds’ nests of surge strips. Those strips aren’t there because people are concerned about surge protection. They’re there because people have far more equipment to plug in than they have available receptacles.

To avoid the fire hazard of daisy-chained surge strips, think about the intended use and provide enough receptacles to support the likely loads. For example, for the typical three-bedroom home 20 years ago it was common to run the receptacles for all three bedrooms and a bathroom on one branch circuit. It’s a bit more costly, but far more resident-rational today to give each room its own receptacle branch circuit. In commercial offices, inadequate receptacle counts often result in fire hazard “solutions.”

Source: Mark Lamendola | Mindconnection

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