PST6250.332-L

Product Description

The Bosch PST6250.332-L is a thyristor based power unit which is optimized for operating welding transformers. The basic purpose of a thyristor is to control electric power by acting as a switch. Inspite of being a small and lightweight component, a thyristor is able to provide adequate protection to circuits with large currents and voltages. Thyristor power controllers are operated with AC voltages. In the case of the PST6250.332-L the thyristor is operated by a three-phase AC voltage between 400 and 600 Volts AC. The maximum continuous thermal current rating of the supply unit is 200 Amps. Maximum duty cycle of the power unit is restricted to 50% through the use of a 2.2 kiloohms de-excitation resistor. The built-in weld timer on the power supply is rated for nominal 24 Volts DC and can operate with DC input between 19 and 30 Volts DC.

The PST 6250 series to which the PST6250.332-L belongs are air cooled supplies which can be used to operate weld timers with peak power rating of 250 kVA. The power supply is available in a housing with environmental protection rating of IP 20. Bosch recommends mounting of the PST6250.332-L in a IP 54 rated industrial switch cabinet. The mounting can be vertical or with the back of the power supply on a mounting plate. Approximate weight of the supply is 27.5 pounds. The power unit contains a thermostatic switch which sends an alarm message to the weld timer if the ambient temperature goes above 80 degrees Celsius. When this happens the green LED on the front of the supply unit goes off. The ambient temperature can cross the alarm threshold if dirt has accumulated on the heat sink, sufficient air flow is not available around the unit or the capacity of the thyristor power unit is too low. This unit can be shipped globally with a one-year warranty period from Wake Industrial.