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Output bleed resistance

The MagnaDC power supply output consists of a large bank of capacitors used to filter output ripple. In parallel with these capacitors, a resistive bleeder circuit is provided to discharge the capacitors to safe levels when the power supply is not in use. The bleeder circuit is transparent to the product's voltage and current measurements. As the output of the power supply is regulated at the product's output terminals, the bleeder will be out of the circuit while the supply's output is enabled. When the power supply is in standby or switched off, the bleeder circuit will apply a load on the DC bus. If a discharge into the power supply's output is undesired, a blocking diode will prevent, for example, batteries or capacitors connected to the DC bus from bleeding into the power supply's output when the power supply is in standby or turned off.

The amount of bleed resistance varies by power level and the model's peak output voltage rating. While the high voltage or high power product utilize passive resistance rated for the peak voltage of unit, the low- to medium-voltage products utilize a constant power electronic bleeder, providing near equal loading at all voltage levels. Table 1 provides the integrated bleed resistance for the MagnaDC rack-mount products. Table 2 provides the integrated bleed resistance for MagnaDC floor-standing products.

Table 1. Output bleed resistance for SL Series MagnaDC programmable power supplies.

Power Level	1.5 kW to 8 kW	1.5 kW to 8 kW
Max Output Voltage Rating	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc
Bleeder Resistance	50 watts	25 watts
Constant Power	No	Yes

Table 2. Output bleed resistance for XR Series MagnaDC programmable power supplies.

Power Level	2 kW to 10 kW	2 kW to 10 kW
Max Output Voltage Rating	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc
Bleeder Resistance	50 watts	25 watts
Constant Power	No	Yes

Table 3. Output bleed resistance for TS Series MagnaDC programmable power supplies.

Power Level	5 kW to 15 kW	5 kW to 15 kW	20 kW and 25 kW	20 kW and 25 kW	20 kW and 25 kW	20 kW and 25 kW	30 kW	30 kW	40 kW	40 kW	50 kW	50 kW
AC Input Voltage	All	All	208/240 Vac	208/240 Vac	380/415 Vac or 440/480 Vac	380/415 Vac or 440/480 Vac	All	All	All	All	All	All
Max Output Voltage Rating	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc
Bleeder Resistance	50 watts	25 watts	100 watts	50 watts	50 watts	25 watts	100 watts	50 watts	100 watts	50 watts	100 watts	50 watts
Constant Power	No	Yes	No	Yes	No	Yes	No	Yes	No	Yes	No	Yes

Table 4. Output bleed resistance for MS Series MagnaDC programmable power supplies.

Power Level	30 kW	30 kW	45 kW	45 kW	60 kW	60 kW	75 kW	75 kW
Max Output Voltage Rating	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc	< 16 Vdc or > 1000 Vdc	≥ 16 Vdc or ≤ 1000 Vdc
Bleeder Resistance	100 watts	50 watts	150 watts	75 watts	200 watts	100 watts	250 watts	125 watts
Constant Power	No	Yes	No	Yes	No	Yes	No	Yes

Table 5. Output bleed resistance for MT Series MagnaDC programmable power supplies.

Power Level	100 kW to 250 kW
Max Output Voltage Rating	All
Bleeder Resistance	500 watts
Constant Power	No

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