UL 921:2000 pdf download Commercial Electric Dishwashers
1 Scope
1.1 These requirements cover commercial freestanding, under-counter, and counter-insert dishwashersand glass-washers for use with water as the principal cleaning medium. These requirements coverdishwashers rated 600 volts or less, employing no universal motor rated more than 250 volts, for use inordinary locations in accordance with the National Electrical Code, NFPA 70.
1.2 A commercial dishwasher may be provided with immersion-type electric heaters for heating water inopen tanks. A dishwasher that utilizes some other source of energy – such as gas or steam — in additionto electric energy wll be investigated under these requirements and under such additional requirementsas are applicable to the dishwasher under consideration. Storage-tank water heaters and electric boilersare not covered by these requirements.
1.3 These requirements cover dishwashers intended for use in commercial establishments such askitchens of restaurants, hospitals and the like, where they are ordinarily not accessible to the generapublic.
1.4 A product that contains features, characteristics, components, materials, or systems new or differentfrom those covered by the requirements in this standard, and that involves a risk of fire, electric shock, oiinjury to persons shall be evaluated using the appropriate additional component and end-productrequirements to determine that the level of safety as originally anticipated by the intent of this standard ismaintained.A product whose features, characteristics, components, materials, or systems conflict withspecific requirements or provisions of this standard shall not be judged to comply with this standardWhere appropriate, revision of requirements shall be proposed and adopted in conformance with themethods employed for development, revision, and implementation of this standard.
1.4 revised March 16.2000
2 Glossary
2.1 For the purpose of this standard the following definitions apply.
2.2 AUTOMATICALLY CONTROLLED – A dishwasher or a unit of a system for which energization of amotor, a solenoid, a magnet, or the like will occur without manual intervention, or during any singlepredetermined cycle of operation, automatic changing of the mechanical load can reduce the speed of amotor sufficiently to reestablish starting-winding connections to the branch circuit.
2.3 CONTINUOUS-DUTY MOTORS – A motor that, under any normal condition of use, can operateunattended and under load for 3 hours or more.
2.4 LINE-VOLTAGE CIRCUIT – A line-voltage circuit is one involving a potential of not more than 600volts and having circuit characteristics in excess of those of a low-voltage circuit.
2.5 LOW-VOLTAGE CIRCUIT – A low-voltage circuit is one involving an open-circuit potential of notmore than 30 volts supplied by a primary battery, by a standard Class 2 transformer, or by acombination of a transformer and a fixed impedance that, as a unit, complies with all performancerequirements for a Class 2 transformer.
2.6 REMOTELY CONTROLLED – A dishwasher or a unit of a system that is out of sight of an operatorwho is at the device by which the dishwasher is started.