geofftheelectrician
Lifetime Supporting Member
In Canada the standard industrial voltage is 600 VAC 3 phase, often from a wye system so the resultant vector is 347 VAC to ground. Over my decades, I've worked on a lot of European designed machines I personally don't like delta fed systems because IMHO the floating ungrounded wires can be a nightmare. In our code we require ground fault indicators on systems to show any fault potentials or leakages.
A lot of the European machines I've worked on have been well built and have had a variety of wiring styles and numbering systems. Most of the Euro machine builders will accommodate the North American voltages where possible, the biggest issue I found at my current employer is getting used to the drawing style. In our plant we have some machines that are fed by a 480V (US industrial voltage) feeder, because of the number of servos on the machine and AB doesn't make 600V servo motors, where others have a 600 delta to 480 wye step down transformer internal to the machine to feed the servo controllers.
What I find the main issue is getting used to other drawing styles and realizing what someone else is trying to depict in their drawing and wiring. I think probably the most dangerous machine I have ever worked on was an Italian designed machining centre for brass stock to make water valve parts. The customer wanted me to add a safety PLC for the new OHSA requirements. The manufacturer had built the machine to the standard Canadian voltage for 600V for the incoming power and distribution to the drive motors but all the controls were 24VDC, which included a 7' (2.2m) high by 6' (1.8m) wide cabinet that was FULL of cube relays and motor starters. They had a 60A DC power supply to supply all the controls that went to 3 20A fuses with 12AWG wires coming off the 20A fuses. So far that was ok but I found out there was a huge problem when I accidentally pinched a DC positive wire under a metal wire trough cover, that the bank of glass fuses was on the negative side of the relays and other devices and the negative from the power supply was grounded.
The smoke and melting insulation of the 16AWG (1.5mm) was a dead giveaway there was an issue...... It took hours to check all the wiring and rework the fusing and run away from that job when I was done.
A lot of the European machines I've worked on have been well built and have had a variety of wiring styles and numbering systems. Most of the Euro machine builders will accommodate the North American voltages where possible, the biggest issue I found at my current employer is getting used to the drawing style. In our plant we have some machines that are fed by a 480V (US industrial voltage) feeder, because of the number of servos on the machine and AB doesn't make 600V servo motors, where others have a 600 delta to 480 wye step down transformer internal to the machine to feed the servo controllers.
What I find the main issue is getting used to other drawing styles and realizing what someone else is trying to depict in their drawing and wiring. I think probably the most dangerous machine I have ever worked on was an Italian designed machining centre for brass stock to make water valve parts. The customer wanted me to add a safety PLC for the new OHSA requirements. The manufacturer had built the machine to the standard Canadian voltage for 600V for the incoming power and distribution to the drive motors but all the controls were 24VDC, which included a 7' (2.2m) high by 6' (1.8m) wide cabinet that was FULL of cube relays and motor starters. They had a 60A DC power supply to supply all the controls that went to 3 20A fuses with 12AWG wires coming off the 20A fuses. So far that was ok but I found out there was a huge problem when I accidentally pinched a DC positive wire under a metal wire trough cover, that the bank of glass fuses was on the negative side of the relays and other devices and the negative from the power supply was grounded.
The smoke and melting insulation of the 16AWG (1.5mm) was a dead giveaway there was an issue...... It took hours to check all the wiring and rework the fusing and run away from that job when I was done.