UL 296A-2009 pdf download – Waste Oil-Burning Air-Heating Appliances.
3.1 5 CONTROL, PRIMARY SAFETY – A control that is directly responsive to flame properties and that senses the presence or absence of flame and, in event of ignition failure or unintentional flame extinguishment, causes safety shutdown. 3.1 6 CONTROL, SAFETY – An automatic control, such as a relay or switch, used in conjunction with other auxiliary equipment to form a safety control system that is relied upon to reduce the risk of fire, electric shock, and injury to persons. 3.1 7 DRAFT REGULATOR, BAROMETRIC (AUTOMATIC DAMPER) – A device that functions to maintain a desired draft in the appliance by automatically reducing excess chimney draft to the desired value. 3.1 8 ELECTRICAL CIRCUITS: a) High-Voltage Circuit – A circuit involving a potential of no more than 600 volts and having circuit characteristics in excess of those of a low-voltage circuit (or an isolated limited secondary circuit); b) Isolated Limited Secondary Circuit – A circuit of limited energy derived from an isolated secondary winding of a transformer having a maximum capacity of 1 00 volt-amperes and an open-circuit secondary voltage rating not exceeding 1 000 volts; c) Low-Voltage Circuit – A circuit involving a potential of no more than 30 volts rms alternating- current (42.4 volts peak) or direct current and: 1 ) Supplied by a Class 2 transformer, or by a battery, by a battery and fixed impedance, by a transformer and fixed impedance each of which complies with the requirements for a Class 2 transformer as specified in the Standard for Low Voltage Transformers – Part 1 : General Requirements, UL 5085-1 , and the Standard for Low Voltage Transformers – Part 3: Class 2 and Class 3 Transformers, UL 5085-3; or 2) Limited to a maximum of 1 00 volt-amperes. A circuit derived from a source of supply classified as a high-voltage circuit, by connecting resistance in series with the supply circuit to limit the voltage and current, is not considered to be a low-voltage circuit;d) Safety Control Circuit – A circuit involving one or more safety controls. 3.1 8 revised December 1 1 , 2009 3.1 9 EXCESS AIR – Air that passes through the combustion area and the appliance flues in excess of that which is theoretically required for complete combustion. 3.20 FLUE, APPLIANCE – The flue passages within the appliance. 3.21 FLUE COLLAR – That portion of an appliance intended for attachment of the chimney or vent connector. 3.22 FURNACE, CENTRAL WARM-AIR – A self-contained indirect-fired appliance constructed to supply heated air through ducts to spaces remote from or adjacent to the appliance location. 3.23 FURNACE, DOWNFLOW – A forced-air type central furnace constructed with air flow through the furnace essentially in a vertical path, discharging air at or near the bottom of the furnace as shown in Figure 3.1 .