【正文】 2) K above the conductor normal operating temperature indicated in Annex C of EN 504831 for approximately 1 h and letting them cool down naturally to ambient temperature. BS EN 504835:2020 EN 504835:2020 – 13 – Installation of the connectors Connectors shall be installed according to the manufacturer’s installation instructions. For bolted connectors A torque meter shall be used for all tightening operations. The accuracy and resolution of the torque meter is given in EN 504831. The connectors shall be held in position during tightening. Connectors shall be tightened to the minimum manufacturer’s declared torque (connectors with shear head) or 90 % of the nominal manufacturer’s declared torque (connectors without shear head). Tightening shall be realised in accordance with EN 504831, . The rate of tightening shall be in accordance with EN 504831, . W hen a connector provides independent tightening facility for main pierced and branch stripped connections, the branch stripped connection shall be mounted 4 times and fully removed 3 times. The branch conductor shall be prepared before the first installation and this prepared end shall be used for the whole of the test. The orientation of the branch cable, with respect to the connector, shall be maintained. Measurement Method of temperature measurement The temperature of a reference conductor or of a connector shall be measured with a thermocouple located at the point shown in Figure 2. Accuracy of temperature measurement shall be 177。 Distances la or l b mm A ≤ 50 150 50 A ≤ 120 200 120 A ≤ 240 250 If A1 ≠ A2, the crosssection of the reference conductor related to conductor A1 shall be A 1 and the crosssection of the reference conductor related to A2 shall be A2 . Both reference conductors shall have the same length lr = la + lb . Potential points shall be placed at a distance la and lb from the nearest surface of the connector body. Conductor length between connectors shall be a distance d, expressed in millimetres, at least equal to 80 √A, subject to a minimum of 500 mm. In the case of branch connectors, A shall be the crosssection of main conductor. W here a test loop prises of only one crosssection of conductor, a single reference conductor shall be used. W here a test loop prises of more than one crosssection of conductor, one reference conductor shall be required for each crosssection. One (two) insulated length(s) of conductor(s) that constitute the heating loop shall be called the reference conductor(s)。C and recorded. Equalizers For stranded conductors, potential between the strands at measuring points can cause errors in measuring electrical resistance. W elded or soldered equalizers, as shown in Annex A, shall be used to overe this problem, and to ensure uniform current distribution in the reference conductor. Welded or soldered equalizers shall be the remended methods to ensure reliable measurements. NOTE Other methods may be used provided that they give parable results and do not affect the temperature of the connectors or the reference conductor. Annex A provides details on the construction of welded equalizers. BS EN 504835:2020 EN 504835:2020 – 10 – Lengths and configurations of conducting paths Ke y A, B, C, D, E, F equalizers (see Annex A). 1 conductor 1 A1 and A2 crosssections relative to conductivity of the conductors 1 and 2 in mm178。C. During the connector installation and resistance measurements, ambient temperature shall remain within the limits of (23 177。 for terminal lugs. Optional immersion test EN 504836, provides an optional immersion test for samples which are intended for use in saline polluted areas. W hen the inclusion of this test has been agreed between the manufacturer and the customer this heat cycle test shall be modified to acmodate immersion of the test samples during each cycle. Disconnection devices The test circuit may include sectioning joints so that it can be dismantled and shortcircuit tests can be made easily. In Figure 6, the disconnection devices (X) are ? closed when the circuit is carrying heating current, and ? opened when resistance measurements and shortcircuit applications are being made. BS EN 504835:2020 EN 504835:2020 – 9 – The sectioning joints shall be arranged and constructed so that they do not significantly affect the measurements. Conductors Phase and neutral conductors including reference conductors used in the test circuit shall remain insulated (except bare conductors). Method of measuring ambient temperature It is important that ambient temperature is measured accurately and is not affected by the heating produced by the test. The following provides a proven method for achieving this measurement though alternative methods can be used. Ambient temperature shall be measured at the middle of the test loop with a thermocouple whose junction is placed in a polished metallic tube manufactured from metal foil formed into a cylinder. Its height shall be 100 mm and its diameter shall be between 35 mm and 45 mm. The thermocouple shall be located approximately at one third of the tube height from its upper end and fitted to it (. with a crosssupport). Ambient conditions The test loop shall be installed in a location where the air is not disturbed. The ambient temperature of the test location shall be between 15 176。 for main and branch connectors having unequal crosssections and linear resistance(s)。C β mean scatter of the connector resistance