EN 812-2012 pdf download.Industrial bump caps.
The burner shall be suitable for propane gas, with a 10 mm diameter bore, an adjustable air vent and an appropriate size of jet. The system shall incorporate a pressure control device, suitable manometer and a tap.
The gas used shall be propane having a minimum purity of 95 %.
6.8.3 Test procedure
Adjust the gas pressure to (3430 i 50) Pa.
NOTE This Is equal to (350±5) mm water
Adjust the flame by means of the air vent so that the blue cone is clearly defined, although turbulent, and is (45 ± 5) mm long.
With the bump cap upside down, and angled to bring horizontal the plane tangential to the test point. and with the burner pointing upwards at 450 to the vertical, apply the end of the flame to the outside of the bump cap, at any suitable point between 50 mm and 100 mm from the crown, for a period of 10 s. Examine the shell for flaming. 5 s after the removal of the flame.
6.9 ElectrIcal properties
6.9.1 Test I
The leakage current between the outside and inside of the bump cap and chin strap (as supplied by the bump cap manufacturer) is measured at a specified voltage, when the bump cap is mounted on a metal headform.
Immerse the sample bump cap and chin strap completely in fresh tap water at room temperature for a period of (15 ± 2) mm. Then remove the bump cap from the water and allow to drain not longer than 20mm.
Mount the sample bump cap crown uppermost on an appropriate sized aluminium headforrn, with the chin strap firmly secured.
Apply an alternating test voltage at nominally 50 Hz or 60 Hz between the aluminium headform and a suitably insulated hand-held metal probe of 4 mm diameter and with a hemispherical radiused end.
Apply the probe at any point on the external surface of the bump cap shell situated at. or above, its lower edge. Repeat the test In order to investigate a number of test points.
At each test point increase the voltage to (1 200 ± 25) V (a.c.), and maintain at this value for 15 s. Record the leakage current at this voltage together with any evidence of breakdown.
The leakage current between the inside and the outside of the bump cap shell is measured at a specified voltage.
Before the test, place the bump cap shell for (24 ± 0.5) h in a (3 ± 0,2) g/l solution of sodium chloride at a temperature of (20 ± 2) C. Then remove the bump cap shell, wipe and place upside down in a container of appropriate size. Fill the container and the bump cap shell with the sodium chloride solution, up to 10 mm below the lower edge of the shell.
Apply an alternating test voltage at nominally 50 Hz or 60 Hz between an electrode immersed in the solution inside the bump cap shell and another electrode in the container, outside of the bump cap shell.
Increase the voltage to (1 200 ± 25) V (a.c.) and maintain at this value for 15 s. Record the leakage current at this voltage, together with any evidence of breakdown.
NOTE The onentation of the bump cap shell in the sodium chloride solution for the test should be adjusted where necessary In order to accommodate shells whose lower edge Is not straight
6.9.3 Test 3
The leakage current between any two points on the surface of the bump cap shell is measured at a specified voltage.
Ensure that the shell of the bump cap is dry before the test.
Apply an alternating test voltage at nominally 50 Hz or 60 Hz between two suitably insulated hand held metal probes of 4 mm diameter and with hemispherical radiused ends.
Apply the probes at any two points on the surface of the bump cap shell (inside and/or outside) located not closer than 20 mm to each other. Repeat the test in order to investigate a number of pairs of test points.
At each test point, increase the voltage to (1 200 i 25) V (a.c.) and maintain at this value for 15 s. Record the leakage current at this voltage, together with any evidence of breakdown.
7 Marking and information
7.1 Markings on the bump cap
Every bump cap claimed to comply with the requirements of this European Standard shall carry durable marking giving the following information:EN 812-2012 pdf download.