Sidactor Protection Thyristor Products Page 63 SIDACtor Protection Thyristor Products

SIDACtor Protection Thyristors 2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 Clause 6.1.2 Separation of the telecommunication network from earth contains the following test requirements: 1) For applications where the nominal ac mains supply > 130 V, a 1.5 kV insulation test is conducted with surge suppressors bridging the insulation barrier removed (applied between tip/ring and earth) 2) For applications where the nominal ac mains supply < 130 V, a 1 kV insulation test is conducted with surge suppressors bridging the insulation barrier removed (applied between tip/ring and earth) 3) IF the surge suppressors were removed then the tip and ring leads are connected together with surge suppressors connected and: a) for case #1 above a 230 V 50 /60 Hz signal is applied through a 5 k ohm resistor between them and protective earth with surge suppressors connected. The current must be < 10 mA. b) for case #2 above a 120 V 50 /60 Hz signal is applied through a 5 k ohm resistor between them and protective earth with surge suppressors connected. The current must be < 10 mA. The voltage applied to the insulation under test for test condition 1 and 2 above is gradually raised from zero to the prescribed voltage and held at that value for 60 S. Surge suppressors that connect to protective ground shall have a minimum operating voltage that is equal to: 1) (180 V + 20% of its rated operating voltage) for ac mains < 130 V and 2) (360 V + 20% of the rated operating voltage) for ac mains > 130V These separation requirements do NOT apply to any of the following: 1) permanently connected equipment or pluggable equipment type B 2) equipment that is intended to be installed by a service person and has instructions requiring the equipment be connected to a socket-outlet with a protective earthing connection OR 3) equipment that has provision for a permanently connected earthing conductor and is provided with instructions for installation of that conductor The electric strength test for telecommunication networks contains two test condition categories. Compliance is checked by testing to one of these two categories. This is intended to protect users from overvoltages on the telcom network. 1) Impulse Test 10 10x700 S voltage waveshape surge event with an open circuit value of 2.5 kV and a 5x310 current waveshape with a short circuit value of 62.5A between all tip and rings connected together and any hand-held part of the EUT (with a minimum of 60 S between surge events) 10 10x700 S voltage waveshape surge event with an open circuit value of 1.5 kV and a 5x310 current waveshape with a short circuit value of 37.5A between all tip and rings connected together and earth ground connection of the EUT (with a minimum of 60 S between surge events); surge suppressors are allowed to operate 10 10x700 S voltage waveshape surge event with an open circuit value of 1.5 kV and a 5x310 current waveshape with a short circuit value of 37.5A between all tip and rings connected together and any other conductors that are intended to be connected to other equipment all tied together (with a minimum of 60 S between surge events); surge suppressors are allowed to operate 2) Steady State ac test of 1.5 kV is applied between all tip and rings connected together and any hand-held part of the EUT (surge suppressor across the insulation barrier are not removed) the ac test of 1 kV is applied between all tip and rings connected together and earth ground connection of the EUT (surge suppressor across the insulation barrier are removed but then must pass impulse test listed above) the ac test of 1 kV is applied between all tip and rings connected together and any other conductors that are intended to be connected to other equipment all tied together (surge suppressor across the insulation barrier are removed but then must pass impulse test listed above) There can be no breakdown of the insulation barrier. Any surge suppressors across the insulation barrier that was removed for the 1 kV steady-state tests but then must comply with the impulse tests. ANNEX C of UL 60950-1 covers transformers The secondary side is loaded for maximum heating effect. The maximum working voltage is applied to the primary. The DC peak value of any superimposed ripple shall be included. The permitted temperature limits for the windings depend on the classifications listed at right: Class A limit is 150 C. Class B limit is 175 C. Class E limit is 165 C. Class F limit is 190 C. Class H limit is 210 C. Regulatory Requirements (continued)

Previous Page
Next Page