Limited Power Source - Contemporary Controls BAST-221C User Manual

Limited Power Source

3.2
The BASstat thermostats accept 24VAC only with no more than 5VA of power consumption and
should be powered by a limited power source complying with the requirements of the National
Electric Code (NEC) article 725 or other international codes meeting the same intent of limiting
the amount of power of the source. Under NEC article 725, a Class 2 circuit is that portion of the
wiring system between the load side of a Class 2 power source and the connected equipment.
For AC or DC voltages up to 30 volts, the power rating of a Class 2 power source is limited to
100 VA. The transformer or power supply complying with the Class 2 rating must carry a
corresponding listing from a regulatory agency such as Underwriters Laboratories (UL).
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