fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
I'm looking for constructive criticism on the following, and if you think it is merited, support in the form of comments from you on 19-45__19-77. Thanks, Jim Williams
4 Comment:
IV. Nominal 120-Volt, 208Y/120-Volt, or 120/240-Volt Systems
551.40 120-Volt, 208Y/120-Volt, or 120/240-Volt, Nominal, Systems.
(A) General Requirements. The electrical equipment and material of recreational vehicles indicated for connection to a wiring system rated 120 volts, nominal, 2-wire with equipment grounding conductor, or a wiring system rated 120/240 volts or 208Y/120 volt nominal, 3-wire with equipment grounding conductor, shall be listed and installed in accordance with the requirements of Parts I, II, III, IV, and V of this article. Electrical equipment connected line-to-line shall have a voltage rating of 208?230 volts.
551.42 Branch Circuits Required.
(C) Two to Five 15- or 20-Ampere Circuits. A maximum of five 15- or 20-ampere circuits to supply lights, receptacle outlets, and fixed appliances shall be permitted. Such recreational vehicles shall be permitted to be equipped with panelboards rated 120 volts maximum, 208Y/120 volt, or 120/240 volts maximum and listed for 30-ampere application supplied by the appropriate power-supply assemblies. Not more than two 120-volt thermostatically controlled appliances (e.g., air conditioner and water heater) shall be installed in such systems unless appliance isolation switching, energy management systems, or similar methods are used. [ROP 19?45]
551.60 Factory Tests (Electrical). Each recreational vehicle designed with a 120-volt , 208Y/120 volt, or a 120/240-volt electrical system shall withstand the applied potential without electrical breakdown of a 1-minute, 900-volt ac or 1280-volt dc dielectric strength test, or a 1-second, 1080-volt ac or 1530-volt dc dielectric strength test, with all switches closed, between ungrounded and grounded conductors and the recreational vehicle ground. ?.
551.72 Distribution System. Receptacles rated at 50 amperes shall be supplied from a branch circuit of the voltage class and rating of the receptacle. Other recreational vehicle sites with 125-volt, 20- and 30-ampere receptacles shall be permitted to be derived from any grounded distribution system that supplies 120-volt single-phase power. The neutral conductors shall not be reduced in size below the size of the ungrounded conductors for the site distribution. The neutral conductors shall be permitted to be reduced in size below the minimum required size of the ungrounded conductors for 208-volt or 240-volt, line-to-line, permanently connected loads only.
5 Statement of Problem and Substantiation
Make voltage consistent in Article 551.
551.4(A) General Requirements.
(A) Not Covered. A recreational vehicle not used for the purposes as defined in 551.2 shall not be required to meet the provisions of Part IV pertaining to the number or capacity of circuits required. It shall, however, meet all other applicable requirements of this article if the recreational vehicle is provided with an electrical installation intended to be energized from a 120-volt, 208Y/120-volt, or 120/240-volt, nominal, ac power-supply system.
(B) Systems. This article covers combination electrical systems, generator installations, and 120-volt, 208Y/120- volt, or 120/240-volt, nominal, systems.
4 Comment:
IV. Nominal 120-Volt, 208Y/120-Volt, or 120/240-Volt Systems
551.40 120-Volt, 208Y/120-Volt, or 120/240-Volt, Nominal, Systems.
(A) General Requirements. The electrical equipment and material of recreational vehicles indicated for connection to a wiring system rated 120 volts, nominal, 2-wire with equipment grounding conductor, or a wiring system rated 120/240 volts or 208Y/120 volt nominal, 3-wire with equipment grounding conductor, shall be listed and installed in accordance with the requirements of Parts I, II, III, IV, and V of this article. Electrical equipment connected line-to-line shall have a voltage rating of 208?230 volts.
551.42 Branch Circuits Required.
(C) Two to Five 15- or 20-Ampere Circuits. A maximum of five 15- or 20-ampere circuits to supply lights, receptacle outlets, and fixed appliances shall be permitted. Such recreational vehicles shall be permitted to be equipped with panelboards rated 120 volts maximum, 208Y/120 volt, or 120/240 volts maximum and listed for 30-ampere application supplied by the appropriate power-supply assemblies. Not more than two 120-volt thermostatically controlled appliances (e.g., air conditioner and water heater) shall be installed in such systems unless appliance isolation switching, energy management systems, or similar methods are used. [ROP 19?45]
551.60 Factory Tests (Electrical). Each recreational vehicle designed with a 120-volt , 208Y/120 volt, or a 120/240-volt electrical system shall withstand the applied potential without electrical breakdown of a 1-minute, 900-volt ac or 1280-volt dc dielectric strength test, or a 1-second, 1080-volt ac or 1530-volt dc dielectric strength test, with all switches closed, between ungrounded and grounded conductors and the recreational vehicle ground. ?.
551.72 Distribution System. Receptacles rated at 50 amperes shall be supplied from a branch circuit of the voltage class and rating of the receptacle. Other recreational vehicle sites with 125-volt, 20- and 30-ampere receptacles shall be permitted to be derived from any grounded distribution system that supplies 120-volt single-phase power. The neutral conductors shall not be reduced in size below the size of the ungrounded conductors for the site distribution. The neutral conductors shall be permitted to be reduced in size below the minimum required size of the ungrounded conductors for 208-volt or 240-volt, line-to-line, permanently connected loads only.
5 Statement of Problem and Substantiation
Make voltage consistent in Article 551.
551.4(A) General Requirements.
(A) Not Covered. A recreational vehicle not used for the purposes as defined in 551.2 shall not be required to meet the provisions of Part IV pertaining to the number or capacity of circuits required. It shall, however, meet all other applicable requirements of this article if the recreational vehicle is provided with an electrical installation intended to be energized from a 120-volt, 208Y/120-volt, or 120/240-volt, nominal, ac power-supply system.
(B) Systems. This article covers combination electrical systems, generator installations, and 120-volt, 208Y/120- volt, or 120/240-volt, nominal, systems.