3-20 BOP HIPWR 111315For inductive loads, and especially superconducting magnet typeloads, the inherent offset of the BOP in the OFF state may generate sig-nificant current in the circuit. A properly rated switch in parallel with aresistor must be connected between the power supply and the load.The switch must be open and the BOP front panel LCD must read 0V,0A before removing or installing connections between BOP and load.ACTIVE. Active mode (default setting) is necessary for the power supply to function properlyand safely with inductive loads and constant-current-type active electronic loads. Active modecan also be used with resistive loads. Table 3-6 indicates how the power supply responds to acommand to go from Output ON to OFF. When the output is disabled, the unit is set to voltagemode, voltage is set to zero and both current protect and voltage limit are set to maximum.When the unit is enabled, the pre-existing settings for voltage, current protect and voltage limitare restored.For both inductive loads and constant-current-type active electronicloads when the BOP output is set to OFF, a path is provided for absorb-ing either the energy accumulated in the reactance of the load duringthe ON state, or energy delivered by an electronic load. This preventsdamage to the load and power supply as well as providing safety forthe user. However, In addition to the built-in safety features, constant-current-type active electronic loads must be adjusted to zero and theBOP front panel LCD must read 0V, minimum current, before handlingthe power supply-to-load connections.RESISTIVE. This mode, as the name suggests, is useful for resistive loads. Table 3-6 indicateshow the power supply responds to a command to go from Output ON to OFF.TABLE 3-6. POWER SUPPLY BEHAVIOR WHEN OUTPUT IS SET TO OFFLOAD TYPESETTINGIf unit was in Voltage Mode when output OFFcommand issued.If unit was in Current Mode when output OFFcommand issued.ACTIVE• Unit remains in voltage mode.• Voltage set to zero.• Both ± Current Protect set to maximum.• Both ± Voltage Limit remain at maximum.• Unit set to voltage mode.• Voltage set to zero.• Both ± Current Protect remain at maximum.• Both ± Voltage Limit set to maximum.RESISTIVE• Unit remains in voltage mode.• Voltage set to zero.• Both ± Current Protect set to minimum box values.• Both ± Voltage Limit. remain at maximum.• Unit remains in current mode.• Current set to zero.• Both ± Current Protect set to minimum box values.• Both ± Voltage Limit set to maximum,BATTERY• Unit set to current mode.• Current set to zero.• Both ± Voltage Protect. remain at maximum.• Both ± Current Limit set to maximum.• Unit remains in current mode,• Current set to zero.• Both ± Voltage Protect set to maximum.• Both ± Current Limit remain at maximum.WARNINGWARNING
