Article 522 of the National Electrical Code (NEC) provides the requirements for the control systems found on permanent amusement attractions. This Article covers the installation of control circuit power sources and control circuit conductors for electrical equipment that is integral to a permanent amusement park attraction [Sec. 522.1].
Power sources for control circuits are either power-limited or non-power limited. A source that supplies:
- Power-limited control circuits must not exceed 50V and 1,000VA [Sec. 522.10(A)].
- Non-power-limited circuits must not exceed 300V [Sec. 522.10(B)]
The transformers for these power supplies must conform with the applicable parts of Art. 450 [Sec. 522.10(A)(1) and Sec. 522.10(B)(1)].
These power sources, other than transformers, must be protected by overcurrent devices rated at not more than:
- 167% of the VA rating of the source divided by the rated voltage, if power-limited [Sec. 522.10(A)(2)].
- 125% of the VA rating of the source divided by the rated voltage, if non-power-limited [Sec. 522.10(B)(2)]
Insulated control circuit conductors must be copper [Sec. 522.20]. Conductors can be as small as 30AWG in a listed and jacketed multiconductor cable if within an enclosure or operator station [Sec. 522.21(B)], but must be at least 26 AWG if installed outside an enclosure or operator station [Sec. 522.21(C)].