Equipment for resistance welding-single phase vs three phase, Mechanical Engineering

EQUIPMENT FOR RESISTANCE WELDING-Single phase vs three phase

The resistance welding machines can be connected either across 440 V mains (across two lines) or three phase mains. Among the three phase machines, frequency converter and rectifier systems are the two main categories. Fig. gives the line diagrams of single phase and three phase machines.

790_euip for resist weld.jpg

Single phase machines are simpler, less costly and cheaper than three phase equipments. Maintenance and installation are easier with single phase machines. The single phase machines having the same capacity as the three phase machines, possess the same performance capabilities. The power factor is lower (40 to 50 %) in the former case, but a high kVA demand is required for a brief period. Unless the loads are properly recalculated and properly redistributed and designed, heavy flickers (cyclic and non - cyclic voltage reductions) will results. Though, the total load is not much, fixed charges are high (because of trend by service, power factor, connected load). Because of the decreased frequency in the secondary, the power factor in the case of three phase machines is 85 % or more. They are not generally suitable for welding of thin metal or weld times of three cycles or less is required. Three phase transformers generally have not been applied to multiple electrode or multiple transformer machines since balancing is otherwise possible in those cases.

 

Posted Date: 9/17/2012 4:25:40 AM | Location : United States







Related Discussions:- Equipment for resistance welding-single phase vs three phase, Assignment Help, Ask Question on Equipment for resistance welding-single phase vs three phase, Get Answer, Expert's Help, Equipment for resistance welding-single phase vs three phase Discussions

Write discussion on Equipment for resistance welding-single phase vs three phase
Your posts are moderated
Related Questions
Argon Argon is approximately one and one third times as heavy as air and ten times heavier than helium. Argon, after leaving the torch nozzle, forms a blanket over the weld

Is there a metal that does not contain iron? Ans) Most commercially available aluminum having some other materials, but only accidental traces of iron, if any. For example, Copp


Q. Safety and Loss Prevention? Are there special venting requirements for flammables and toxic materials? Air conditioning, heating and ventilation: • are non-sparking fa

Explain the Construction of dc machine The constructional features of a dc machine are given below. A dc machine has two major parts, magnetic ?eld system and armature. The ?eld

what is the advantage of fan

Pultrusion Structure sections of long length are generated by putting the fibres via resin bath and heated dies of exact shapes. Unidirectional fibres along with high volume f

Determine force on a body to pull or push: Q: A wooden block having weight of 50N rests on the horizontal plane. Determine force required which is acted at an angle of 15° to

Water jet machining is an advanced method for cutting plates using a high-velocity water jet mixed with abrasive powder. The jet comes out of a nozzle A of diameter d and follows t

1. Given the following grammar S à 0A0 | 1B1 | BB; A à C; B à S | A; C à S | ε, (a) ( Derivation ) Given a left-most and right-most derivation of a string 01001110 (b) ( Parse tree