ANSI C78.41:2001 pdf free download – Guidelines for Low Pressure Sodium Lamps
1 Scope
This standard describes the physical and electrical requirements of the principal types of single-ended low pressure sodium lamps. The electrical data provides the specific basis for ballast requirements for these lamps.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
3 Lamp designations
Designations for low pressure sodium lamps are assigned in accordance with ANSI C78.380. For reference, the older designations are shown in parentheses in the lamp data sheets.
4 Bulb Designations
Bulb designations are defined in ANSI C79.1. Due to the long term use of the conventional method of bulb designations, their use will continue herein with the equivalent metric bulb designations shown in parentheses (i.e. BT28 [BT90] ) in contrast with the use of metric primary dimensions elsewhere in this standard.
5 Base specifications
The BY22d base is described in ANSI C81.61.
6 Maximum outline drawings
The maximum outline drawings in Chapter III of this standard show the maximum limits of the space that may be occupied by any part of the bulb for each lamp type. These limits are in accordance with IEC 60192. Most luminaires for low pressure sodium lamps constrain the dome end of the lamp and take up any eccentricity of the lamp by means of a moveable base holder. Accordingly, the maximum outline drawings allow for the maximum bulb diameter at the dome end and for eccentricity at the base end.
7 Methods of measurement
An American National Standard for methods of measuring the electrical characteristics and the bulb and base temperatures of low pressure sodium lamps has not yet been written. Until such a standard is written, general guidelines for these measurements may be found in ANSI C78.386 and IEC 60192.
8.1 Lamp operating characteristics. The values of lamp volts, amperes, and watts shown on the individual lamp data sheets in Chapter II of this standard apply for lamps that have aged 100 hours. Lamp rms voltage may increase with operating hours; contact lamp manufacturer for details.
8.2 Warm-up time. Bare lamps operating in still air shall reach a stabilized voltage within the time limit and at the ambient temperature specified on the applicable lamp data sheet in Chapter II of this standard. For the purposes of this test, low pressure sodium lamps have reached a stabilized voltage when their voltage does not vary more than 2% in any one-minute period. Lamps shall meet this requirement when operated on the appropriate reference ballast specified in Chapter II, Section 4, and in the allowed operating position most adverse to warm-up.