3 phase vs 1 phase

| I have a Nordson hotmelt machine and it requires single phase 240 my | maintenance mechanic has it hooked up to a 3 phase 240 line and he | say's that will work fine. I have been having multiple electrical | problems with these machines and we have been unable to determine what | is the cause. Is it ok to leave 3 phase on single phase requirement?

There would be 2 wires to the machine (plus EGC for protective ground). Probably no neutral. If the incoming power is 240 delta with a center tapped neutral on one side, connecting to the two phases that are 120 volts relative to the neutral is just fine. If it is 208Y/120 then the machine is undervoltage and you'd be getting only about 75% of the heat you should get.

What kinds of electrical problems are you having?

I have replaced to main boards, 32 rtds ( thermal detections) and 1 whole machine

You did not give us much to go on. So we can undestand your power system. What country are you in? What are the power specifications of the machine? Nameplate voltage, Power and frequency. What is the nature of the failures?

Simply put. Any 2 wires of a 3phase system will provide single phase power. Of course the wireing has to be rated for the load and properly protected. But basicly your mechanic will be correct if all the numbers check out.

The important thing is the voltage supplied and the voltage required.

Please tell us some facts.

-- John G.