BS EN 50340-2010 pdf download.Hydraulic cable cutting devices Devices to be used on electrical installations with nominal voltage up to AC 30 kV.
Three steel wires arranged in a bundle but not twisted specified according to EN 10016-2 (diameter 0,5 mm, steel grade C4D, material-number 1.0300), with a length of 450 mm to 500 mm shall be placed in the cutting head. The bundle shall be at a right angles to or perpendicular to the axis of the cutting blade and project equally either side of the line of cut of the blade(s) for a distance of not less than 200 mm.
The wires shall be securely fixed at one end and shall be positioned at the weakest point of the blade(s) which is expected to jam.
The cutting shall be carried out according to the instructions for use.
The test shall be repeated two more times. The wires may be placed at other points of the blade(s) which are considered to be weak.
The test is considered as passed when at the end of all three cutting processes, the cutting head is sufficiently wide open to accept the cable with the maximum permissible diameter,
5.8 Accuracy of cutting
The test shall be carried out with a cable cutting device ready for operation and with a test probe defined below.
The test probe shall be made from high-density polyethylene with a density of 0.94 glcm3, a tear resistance of (450 ± 50) % and a diameter of (50 ± 2,5) mm. The length of the test probe shall be at least 500 mm.
The cutting head shall be placed on a flat surface. The test probe shall be placed in the cutting head so that a length of (200 ± 2) mm projects beyond the line of cut of the cutting blade(s). The other end of the test probe shall be securely clamped.
The cutting head shall rest in that position without additional means of support. The cutting shall be carried out according to the instructions for use.
The test is considered as passed if the length of the cut free part of the test probe is (200 ± 10) mm.
The pump shall be operated without a probe until the pressure gauge shows that the maximum operating pressure has been reached. The force needed to operate the safety valve shall be measured at 50 mm from the end of the handle or the pedal (see Figure 4).
The test is considered as passed if the force does not exceed 500 N for units operated by foot. and 300 N for units operated by hand.
5.10 Stability
The test shall be carried out with a cable cutting device ready for operation without a probe.
According to Figure 5 a) the pump shall be placed on a firm plane base which is inclined at 15° and covered with an insulating mat to EN 61111, Class 0. The pump shall be placed at least 50 cm from the lower edge of the surface. The insulating hose and cutting head and other fittings shall be arranged so that they do not adversely influence the test.
The pump shall be operated until the safety valve operates, Thereafter, the pressure is released by operating the reverse flow valve.
After the blade(s) return to the rest (open) position the assembly shall be rotated through 90° in the horizontal plane, on the base, see Figure 5 b).
A visual inspection shall then be made of the pump, hose, couplers and other fittings to verify that there are no insulating hydraulic fluid leaks.
This part of the test shall be repeated twice more. After each test the pump shall be rotated 90° in the same direction of rotation.
The test is considered as passed if the operating pressure of the safety valve was reached in all four positions, no leaks of insulating fluid occurred, and the pump remained in a working position, I.e. was displaced by less than 50 cm and did not tip whilst being operated.
5.11 Operation of the safety valve
The test shall be carried out with a cable cutting device ready for operation without a probe.
A calibrated pressure gauge shall be connected to the pump.
The pump shall be operated until the safety valve operates. The operating pressure of the safety valve shall be recorded from the indication on the calibrated pressure gauge. Then the pump shall be subjected to the resulting pressure for a period of at least 10 mm.BS EN 50340-2010 pdf download.