OPERATION OF 3-PHASE WELDING EQUIPMENT FROM A 1-PHASE SUPPLY

IN CONJUNCTION WITH TRANSWAVE ROTARY CONVERTERS

Generally speaking, a phase converter is unlikely to be a viable proposition for somebody only wishing to operate three-phase welding equipment from a single phase supply. However if you wish to operate a mixture of inductive and resistive load (i.e. large motor driven equipment as well as welding equipment), the cost of a TRANSWAVE rotary converter can be easily justified.

As welding load is resistive you have no alternative but to consider a rotary converter as this is the only solution that can offer a supply akin to mains 3-phase independently of the welder. The converter should be of sufficient capacity to maintain the voltage on the "artificial phase" when the welder is operated at its maximum current rating.

Some converter sizes need to be modified for welding purposes. When necessary, the modification incorporates a hand/auto switch to bypass the automatic boost circuit. Welding sets that only connect to two phases of a three phase supply (so-called "Two-phase" 415-volt welding sets) can also be operated from dedicated transformers (i.e. no converter is required).

A guide to the recommended sizes of rotary converter and transformer is given below. Note that any TRANSWAVE rotary converter used for welding purposes can still be used for standard motor applications.

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Converter Reference             Welding Current      3-phase input current (approx)       240-volt supply

RT (4.0kW/5.5hp standard)            160A                           08A per phase                           25A                      

RT (7.5kW/10hp standard)             200A                           10A per phase                           40A

RT (7.5kW/10hp standard)             250A                           12A per phase                           40A 

RT (7.5kW/10hp standard)             300A                           15A per phase                           40A

RT (15kW/20hp standard)              350A                            17A per phase                          80A

RT (15kW/20hp standard)              400A                            20A per phase                          80A           **************************************************************************************************************************

Converter Reference             Welding Current   2-phase input current (approx)            240-volt supply             

RT (7.5kW/10hp standard)            160A                           12A per phase                           40A

RT (7.5kW/10hp standard)            200A                           15A per phase                           40A

RT (15kW/20hp standard)             250A                           18A per phase                           80A

RT (15kW/20hp standard)             300A                           24A per phase                           80A

RT (15kW/20hp standard)             350A                           27A per phase                           80A

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Transformer Reference            Welding Current   2-phase input current (approx)            240-volt supply

8550/240V - S5                        160A to 250A                   15A to 23A per phase                   80A

13979/240V - S6                      300A to 400A                    27A to 36A per phase                 100A-120A

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This guide was written by

Tel: 0844 7700272 - Fax: 0844 7700292

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