Strange jumper between elements

[NetNathan]

Can someone explain the jumper between the elements? Does it do anything?
See attached jpeg.

 

[I_Automation]

With 2 separate 50V transformers that jumper would keep the center potential to ground equal between the 2 circuits. And hopefully very close to 0V to ground. Myself I would ground that connection - and maybe it is just didn't make it to CAD.



Otherwise if the resistance of one top element becomes different from the other top element (or bottoms) there could be a potential voltage between the 2 that might be enough to be felt by an operator or technician.

 

[goghie]

I presume that transformers have 50V and 0V on secondary side, not +25V, -25V. And yes as I_Automation mentioned it should be grounded. Otherwise it is error. Even having transformers in parallels with enough difference in wire/busbar resistance is error.

 

[I_Automation]

I presume that transformers have 50V and 0V on secondary side, not +25V, -25V...

I've encountered quite a few machines with a floating power source, especially relay based stamping press controls with un-grounded 120VAC.


The relay coils on these controls are in the middle of the rungs and the 2 sides of the transformer output are +60 / -60.


If this was 2x 24V heaters in series on a (slightly overpowered) 50V supply then none of the transformer output leads would be grounded. I'm still guessing the center jumper IS grounded, just not shown on the schematic.

 

[NetNathan]

Going to have to investigate the actual wiring....