Calculation

The following tables show extracts from typical technical data for conductor rails and power supply cables.

Table 1
Typical technical data for conductor rails
300 A	A in mm²	Z' in mΩ/m	R' in mΩ/m	L' in µH/m
	70	0.321	0.298	0.380
	75	0.269	0.239	0.393

Table 2
Typical technical data for power supply cables
Cu cable	A in mm²	Z' in mΩ/m	R' in mΩ/m	Xl' in mΩ/m	L' in µH/m
	35	0.531	0.524	0.0851	0.271
	50	0.396	0.387	0.0848	0.270
PVC-insulated cable	70	0.280	0.268	0.0823	0.262
	95	0.210	0.193	0.0820	0.261
	120	0.173	0.153	0.0804	0.256
	150	0.148	0.124	0.0804	0.256

The following values are taken from the tables to calculate R_{line 1} and R_{line 2}:

Table 2: Cable cross section for line 1 to the sub-distributor = 120 mm²
Table 1: Cross section of the conductor rails (50 m length) for line 2 = 70 mm²
Table 2: Cross section of the cable (60 m length) for line 2 = 70 mm²

For the MDR91B-0750-.. supply and regenerative module, an overload of 250% results in a permissible total resistance R_total = 105 mΩ.

R_transformer = 3 mΩ

R_{line 1} = 20 m × 0.153 mΩ/m = 3.06 mΩ

R_{line 2} conductor rail portion: R_{line 2_1} = 50 m × 0.298 mΩ/m = 14.9 mΩ

R_{line 2} cable portion: R_{line 2_2} = 4 × 15 m × 0.268 mΩ/m = 16.08 mΩ

R_total = R_transformer + R_{line 1} + R_{line 2_1} + R_{line 2_2}

R_total = 3 mΩ + 3.06 mΩ + 14.9 mΩ + 16.08 mΩ = 37.04 mΩ

Condition: R_total ≤ R_permissible

37.04 mΩ < 105 mΩ → condition fulfilled

The total resistance of the transformer, supply lines, and conductor rails is less than the maximum permissible total resistance up to the input terminals of the line choke.