316 CHAPTER 12 Electricity are replaced). Nonrenewable fuses tend to heat up less and are favored in situations where there is little chance of an overcurrent. Fuses may or may not have a time delay. A time-delay fuse is designed to allow for startup loads, which may briefly exceed the nominal current rating of a piece of equipment. This is the case with motors and with HMIs. Circuit breakers are designed to provide a time delay automatically. As mentioned earlier, circuit breakers and fuses are installed to protect cable and equipment from thermal meltdown, but they are not designed to protect people from shock. The equipment grounding system we shall talk about shortly is one safeguard against electrical shock. When a shock hazard may exist, such as in wet locations, ground fault circuit interrupters (GFCI) must be used to protect against shock hazard from leakage current or equipment faults. GFCI equipment is covered in detail in Chapter 17. The current-carrying capacity of cable There are a number of factors that affect the amperage capacity of cables. An amperage capacity or ampacity is assigned to each type of cable in the NEC based on the wire gauge, type of insulation, and temperature rating of the insulation. This rating may also be required to be adjusted for the ambi- ent temperature, the number of conductors in the cable, the length of time it is under load continu-