Quantech QTC2015T Manual

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Quantech QTC2015T Manual Manual pdf 56 page image

QUANTECHFORM QTC2-eg1 (515)56Circuit Breaker Calculationsmax dual Elem fuse max CB (moP)= 2.25 x Current of largest motor + ∑ (remaining FLAs or RLAs)for this name plate the formula below was used:= 2.25 * rlACpr1 + rlACpr2 + rlACpr3 + Qty* rlAfans + 0.49 + flAPumpThis formula will calculate the ACTUAl moP but a table is referenced to provide the ap-propriate moP. Using an approximate match, look up the value of the calculated ACTUAlmoP in Column A. find the largest value i.e. less than or equal to the value in Column A.once found, the value in Column C which shares the same row is the valued USEd in thesystem. e.g. e.g. Using the same example that was used to calculate the mCA, calculatethe moP:Answer: ACTUAl = 2.25*20.4 + 20.4 + 0 + 2*2.6 + 5.29 = 45.9 + 30.89 = 76.79Com-paring against values in Column A: 70 < 76.79 < 80, therefore the USEd moP found inColumn C is 70.ACTUALCOLUMNAMINIMUMCOLUMNB*MAXIMUMCOLUMNC0 15 015 20 1520 25 2025 30 2530 35 3035 40 3540 45 4045 50 4550 60 5060 70 6070 80 7080 90 8090 100 90100 110 100110 125 110125 150 125150 175 150175 200 175200 225 200225 250 225250 300 250300 350 300350 400 350*Note: Column B is used if one were calculatingthe minimum dual Elem fuse which is not relevantto this exercise.