Firstly, it must be appreciated that IDMT relays cannot be considered in isolation. The trip time is calculated from the following parameters: Trip curve. These spreadsheets below will make your endless calculations much easier! Calculation of IDMT Over Current Relay Settings (50/51/50N/51N) Calculation model for thermal relay Siemens 7SJ64 Get contact details and address | ID: 21039685833 types and applications of overcurrent relay part 1. model setting calculations for typical ieds line. They have to be set to coordinate with both upstream and downstream relays. Home. Calculation of IDMT Over Current - Read online for free. Sign In Join. A relay that operates or picks up when its current exceeds a predetermined value (setting value) is called Over-current Relay. To set the IDMT characteristic of a SEPAM relay, the following parameters should be considered: 1) Type of current transformer and its rated current The primary and secondary rated current of the CTs (1A or 5A), will be determined in the general settings of the relay. When deciding to apply IDMT relays to a network, a number of important points have to be considered. ... (IDMT) over-current Relay is one in which the operating time is approximately inversely proportional to the fault current near pick-up value and then becomes constant above the pick-up value of the relay. Upload. Alternatively, if the current plug setting is chosen as 125% (6.25 A), the fault current through the relay will be 50/6.25 = 8 A. Books. Search Search. Calculate: (a) The secondary current, if the primary current is 840A; (b) The line current, when the IDMT sensed a current of 6A. Read about company. mikro sdn bhd contents. 2) A/B group settings Say current setting of the relay is 150 % therefore pick up current of the relay is 1 × 150% = 1.5 A. Step-3 Now we have to calculate PSM for the specified faulty current level. Saved. Scribd is the world's largest social reading and publishing site. Anjani Power Tech - Offering L&T MC31 ANX Idmt Relay, Model Number/Name: MC61 at Rs 8700/piece in New Delhi, Delhi. (IDMT) Relay Characteristics 1. From current setting we calculate the trick current of the relay. siemens 7sr210 application manual pdf download. Inverse Time Over Current is also referred to as Time Over Current (TOC), or Inverse Definite Minimum Time (IDMT). Close suggestions. Tutorial B6 – IDMT Protection Relay Solution 1. As shown in the figure, the 400/5A current transformer (CT) is connect to a protection IDMT relay. Accordingly, relay settings = current plug tap 5 A (100%) and time multiplier 0.8. 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