Lost voltage

[mikejs]

I have a automatic mattress bagging machine, we ran 240 3 phase delta to it, I have 115v- 120v to ground on all three phases until I turn the heaters on then I 240v to ground on A and B phase and 1v to ground on the C phase, I also read low resistance to ground on that heater element. I'm thinking that's my problem but the machine works fine, I'm just afraid that lost voltage will cause other problems. Has anyone run into this before? Thanks

 

[GoldDigger]

I have a automatic mattress bagging machine, we ran 240 3 phase delta to it, I have 115v- 120v to ground on all three phases until I turn the heaters on then I 240v to ground on A and B phase and 1v to ground on the C phase, I also read low resistance to ground on that heater element. I'm thinking that's my problem but the machine works fine, I'm just afraid that lost voltage will cause other problems. Has anyone run into this before? Thanks

Chances are that you have an ungrounded delta and are reading voltages to ground just from capacitive coupling, while one terminal of the three phase input to the machine is deliberately or accidentally grounded.

This is not something to play with or ignore. You need to find out just how your service (or SDS source) is wired. If ungrounded, a ground detector is mandatory. If high resistance grounded, then you need to fix the machine!

Are you sure the machine is really three phase and not just 240-0-240?