A&D CD - Information Low Voltage Control Systems Application of SIRIUS Contactors at Extreme Ambient Temperatures Nur für internen Gebrauch. Alle Rechte vorbehalten. For internal use only. All rights reserved. Number: 3/9 e Subject: Ambient Temperatures for SIRIUS Contactors S00 to S3 Author: Ms Frank Department: A&D CD CP VM M/E Version: 12/01 Distribution: Tel. 09131/7-21967 Fax 09131/7-24214 E-mail: [email protected] - High Ambient Temperatures - Low Ambient Temperatures A&D CD-Information is available on the Intranet under: http://intra1.erlm.siemens.de/cd/businesspool/ Information No.: 3/9 e Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 2 In accordance with the international and national IEC 60 947 – 4 –1, DIN EN 60 947–4–1 (VDE 0660 Part 102) standards, low-voltage switchgear and controlgear must be designed to be operable at ambient temperatures T a of –5 °C to +40 °C. Furthermore, most of the Siemens switchgear and controlgear can be operated at a temperature range of T a –25 °C to +60 °C, which exceeds the temperature range as specified by the above-mentioned standards. This A & D information enables you to inform your customers on questions concerning the deviations of our contactors from the ambient temperatures stated above. Index A Higher Ambient Temperatures A1 Short-time operation A 1.1 Ambient temperatures of Ta 80 °C A 1.2 Calculation of the average ambient temperature A2 Continuous operation A 2.1 Installation at ambient temperatures of > 60 °C A 2.2 Ambient temperatures of Ta 70 °C A 2.3 Criteria A 2.4 Molded-plastic parts A 2.5 Main circuits A 2.5.1 Load rating of main circuits A 2.5.2 Switching capacity A 2.5.3 Switching frequency A 2.5.4 Conductor cross-sections of the main conductors A 2.6 Operating mechanism A 2.7 Service life B Low Ambient Temperatures Information No.: 3/9 e A Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 3 Higher Ambient Temperatures Application of Contactors Size S00 to S3 A 1. Short-time operation A 1.1 Ambient temperatures of Ta 80° C Ambient temperatures of Ta up to max. 80° C are permitted for a period of one hour without a reduction of the permissible circuits if an average ambient temperature of Ta 60° C is not exceeded within a 24-hour period. In compliance with these conditions, the contactors can also be subjected to the catalog data during continuous operation. For devices that contain electronic components, such as contactors with an extended operating range as well as contactors and coupling contactors with integrated overvoltage damping, the maximum ambient temperature of 60° C, resp. 70° C, must not be exceeded (please refer to Low-Voltage Controlgear, Switchgear and Systems Catalog NSK, Part 3, Technical Data). A1.2 Calculation of the average ambient temperature Example: The average 24-hour ambient temperature (ttotal) is to be calculated. The time period and the temperature levels of the various ambient temperatures are known: 80° C (T1) for 1 hour (t1) 50° C (T2) for 7 hours (t2) 35° C (T3) for 16 hours (t3) T 1t 1T 2t 2 T 3t 3 ttotal 560Ch = 80Ch 35024Ch = 41.25° C h In this case, the average ambient temperature only amounts to approx. 41° C and is thus not problematic, as this value may amount to 60° C, resp. 70° C, without any reductions becoming necessary. Information No.: 3/9 e Subject: Ambient Temperatures for Sirius Contactors S00 to S3 A2 Continuous operation A2.1 Installation at ambient temperatures of T a > 60°C Page: 4 With side-by-side installation of contactors without laterally mounted auxiliary switch blocks, a spacing of 10 mm is required for better heat dissipation. The following data is based on the observance of such spacing. Ambient temperature of Ta 70° C A 2.2 With certain reductions, contactors with conventional operating mechanisms (magnet systems) may also be continuously operated at ambient temperatures of Ta 70° C. For devices with electronic components such as contactors and coupling contactors with integrated overvoltage damping or contactors in combination with additional components (electronically delayed auxiliary switch blocks, electronic time relay blocks, overvoltage limiters, mountable interfaces, etc.), the maximum ambient operating temperature of T a = 60° C must not be exceeded. The 3R...–OLA0 contactors with an extended operating range which are designed for ambient temperatures of up to 70° C are not subject to this rule . A 2.3 Criteria Higher ambient temperatures result in higher stress on the molded-plastic parts main circuits operating mechanisms (coil, magnet system) This may lead to a reduction of the mechanical service life and thus to a reduction of the devices’ operability. Information No.: 3/9 e A 2.4 Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 5 Molded-plastic parts The parts most strongly affected are those contained in the operating mechanism. First and foremost, the temporal period of the higher temperatures negatively effects the mechanical strength of the molded-plastic parts. Long ON duration periods as well as a low switching frequency are, as a rule, more critical than a high switching frequency and short ON duration periods. A 2.5 Main circuits A 2.5.1 Thermal capacity The permissible main circuit’s thermal capacity is subject to the AC-1 or DC-1 values. Within these values, higher ambient temperatures with a respective reduction of the rated operating current Ie/AC-1 or DC-1 and the maximum permissible switching frequency are easy to control. The standard contactors are designed for a maximum ambient temperature of T u = 60° C. The following linear interdependency is valid for higher ambient temperatures of up to max. 70° C: Ie max. = Ie /AC-1 60 C Ta or Ie max. = Ie /DC-1 60 C Ta Ie max. = Rated operating current of the contactor to be calculated at higher ambient temperatures Ie / AC-1 or Ie/ DC-1 = Rated operating current of the contactor for the respective utilization category and Ta 60° C Ta = Actual ambient temperature Ta > 60° C Information No.: 3/9 e A 2.5.2 Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 6 Switching capacity The contactors’ switching capacity is not affected by higher ambient temperatures. The Ie/ AC-3 or Ie/ DC-3/DC-5 rated operating current may, however, not be higher than the contactors’ I e/ AC-1 or DC-1 values for the respective ambient temperatures Ta. This must especially be observed with larger 3RT10 contactors for AC voltage (Ie /AC-3 AC-1). Example: The maximum rated operating current Ie/AC-3 for a 3RT1036 contactor at an ambient temperature of 70° C is required. Based on the catalog data, the rated operating current Ie of this contactor is Ta 60° C: 50 A for utilization categories AC-1 and AC-3. Ie max. = Ie /AC-1 60 C = 50 A Ta 60 C 70 C = 43 A As the rated operating current Ie/AC-1 is specified to be practically equal to the thermal rated current, the rated current of the operating mechanism must naturally not be higher than the calculated AC-1 value (therefore 43 A in the above example). A 2.5.3 Switching frequency The maximum permissible switching frequency “p” must also be reduced at higher ambient temperatures. In principle, the same reduction factor as with continuous operation is to be applied: p max. p [AC-x ] Ie / AC x 400 V 60C I U T 1.5 p max = switching frequency to be calculated for higher ambient temperatures p [AC-x] = switching frequency valid for the applicable utilization category at Ta 60°C (catalog data) Ie /AC-x = rated operating current valid for the applicable utilization category Ta 60°C (catalog data) I actual operating current Information No.: 3/9 e Subject: Ambient Temperatures for Sirius Contactors S00 to S3 U actual operating voltage Ta actual ambient temperature Page: 7 Example: The maximum switching frequency at Ta = 70°C and a rated operating voltage of Ue = 500 V is to be calculated for the 3RT10 46 contactor. The rated current of the operating mechanism amounts to 82 A and the utilization category is AC-3. According to the Low-Voltage Controlgear, Switchgear and Systems Catalog NSK, 850 switching cycles per hour are possible and a rated operating current Ie /AC-3 of 95 A is permissible for this contactor at an ambient temperature of Ta 60 °C and utilization category AC-3. 850 1 h 95 A 400V 1.5 60C 1 = 603 70C h 82 A 500V In accordance with the above mentioned conditions, the contactor may thus be switched 603 times per hour. A2.5.4 Conductor cross sections of the main conductors In order to ensure sufficient heat dissipation at the main circuits, a careful calculation of conductor cross sections must be carried out in compliance with the applicable stipulations! A2.6 Operating mechanism To protect the contactor operating mechanisms (coil, magnet system) from thermal overload at higher ambient temperatures, the operating range limits of the rated control voltage Uc must be restricted. The table (enclosure, last page) shows these limits. Intermediate values may be interpoled linearly. The IEC 60 947 and DIN EN 60 947 (VDE 0660) standards call for an operating range of the magnet coils of 0.85 to 1.1 x Us. Information No.: 3/9 e Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 8 Despite the higher ambient temperature, the lower operating range limit, which is critical for the function, complies with the specified value (exception: S00 DC). A2. 7 Service life Higher ambient temperatures result in a reduction of the contactors’ mechanical service life. The temporal service life is most strongly influenced by the ON duration period. The following table shows the reduced service life values: S0 – S3 Sizes S00 S00-S3 Ambient Mechanical service life, Mechanical service life, Temporal temperature Ta switching cycles switching cycles service life 60°C 30 million 10 million 20 years 65°C 15 million 5 million 15 years 70°C 3 million 1 million 10 years The values for the temporal service life are valid for a 100% ON duration period. With a 50% ON duration period, the values may be doubled. B Low Ambient Temperatures Contactors without electronic components may also be applied at ambient temperatures of below Ta–25°C, given certain conditions are fulfilled. In such cases, however, measures against moisture condensation must be taken (e.g. with distribution board heating). These contactors may be applied at minimum ambient temperatures of T a -50°C in observance of the other catalog data. This will, however, result in a reduced mechanical service life. High switching frequencies and ON duration periods are not as critical to the service life as low switching frequencies and short ON duration periods. The mechanical service life may thus be reduced by up to 50%. Devices that contain electronic components such as contactors and coupling contactors with integrated overvoltage damping or contactors in combination with Information No.: 3/9 e Subject: Ambient Temperatures for Sirius Contactors S00 to S3 Page: 9 electronic components (e.g. electronically delayed auxiliary switch blocks, time relay blocks, overvoltage limiters, mountable interfaces...) may not be applied at temperatures Ta below – 40°C as otherwise the integrated electrical circuits will no longer function properly. This also applies to the DC-operated SIRIUS contactors of size S00 (3RT1/3RH1) as the permanent magnet integrated in the DC-operated devices may be damaged. Note A respective supplement will be issued for size S6 to S12 contactors as soon as the respective technical data is available.