Grounding secondary of a 30KVA single phase transformer 480 to 208

[jap]

I don't run into as many as I once used to. But one has to lose the mentality that a grounded conductor must be a neutral conductor- it can be any conductor of any system. NEC just happens to require that systems that have a neutral conductor must ground the neutral conductor.

Even in your industrial settings, how many 120 volt two wire secondaries do you have for control volts on various machines? There is no neutral on those, pick one side and ground it, pick both sides and you are blowing control fuse or letting smoke out of the transformer if done ahead of any overcurrent devices.

I tend to always ground the one on the right for no particular reason.

It's an X1. X2 thing in proper order for me.

Jap>

 

[LarryFine]

I should agree with K-wired more often.

All of you guys should agree with me more often.

I tend to always ground the one on the right for no particular reason.

It's an X1. X2 thing in proper order for me.

Same here, just like my drawings: hot on the left, grounded on the right.

 

[Jamesco]

Correct. You also need separate grounded and equipment grounding conductors beyond the system bonding point, which is likely going to be within the transformer housing on this one. So even if a fuse would happen to blow within appliance in the grounded conductor it isn't really that dangerous of an issue to the user, might be more risk to someone troubleshooting problems that don't understand what they have to work with.

"So even if a fuse would happen to blow within appliance in the grounded conductor it isn't really that dangerous of an issue to the user,"

Because the OP has abandoned he his own thread we are left with only assumptions. We do not have any information, electrical specs, on the cooking appliance". All we have to work with is a 1ph 480V to 208V 30KVA transformer.

Assume this cooking appliance/equipment will be hard wired. (High probability)
The NEC says it shall Listed. Lets assume the appliance is UL Listed.
Lets assume both 208V lines feeding heating elements are individually fused.

If one leg of the transformer's secondary is grounded, making it the grounded conductor, the grounded conductor will be fused feeding one end of each connected heating element. Do you think the designer of the appliance/equipment would sign off on that? Would UL? Would it void the UL listing? Would it void the manufacturers' warranty?
If you pulled an electrical permit would the electrical inspector agree with your statement, "So even if a fuse would happen to blow within appliance in the grounded conductor it isn't really that dangerous of an issue to the user," and pass the inspection?

If it were me I would call the manufacturer of the cooking appliance before I proceeded doing anything that involved using the transformer in question.
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[kwired]

"So even if a fuse would happen to blow within appliance in the grounded conductor it isn't really that dangerous of an issue to the user,"

Because the OP has abandoned he his own thread we are left with only assumptions. We do not have any information, electrical specs, on the cooking appliance". All we have to work with is a 1ph 480V to 208V 30KVA transformer.

Assume this cooking appliance/equipment will be hard wired. (High probability)
The NEC says it shall Listed. Lets assume the appliance is UL Listed.
Lets assume both 208V lines feeding heating elements are individually fused.

If one leg of the transformer's secondary is grounded, making it the grounded conductor, the grounded conductor will be fused feeding one end of each connected heating element. Do you think the designer of the appliance/equipment would sign off on that? Would UL? Would it void the UL listing? Would it void the manufacturers' warranty?
If you pulled an electrical permit would the electrical inspector agree with your statement, "So even if a fuse would happen to blow within appliance in the grounded conductor it isn't really that dangerous of an issue to the user," and pass the inspection?

If it were me I would call the manufacturer of the cooking appliance before I proceeded doing anything that involved using the transformer in question.
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Using transformer OP has raises many similar kinds of questions if he leaves it ungrounded.

Guess the only thing possible is to supply it from a true three phase 208/120 source?

Non standard 104/208 transformer probably wouldn't be included in any listing either.

Again as I mentioned earlier, who makes an appliance with that high of VA rating @ 208 volts that isn't three phase or at least easily convertible from single phase to three phase?

Maybe it was special ordered that way? Maybe it is used and current owner is stuck with it but if ordering new could have/should have ordered something that works on what they already have (maybe even 480 volts) and then they wouldn't need to field install conversion equipment?