230 volt 3 phase with neutral and ground???

[hunt4679]

I just recieved the specs for a new piece of lab equipment that needs wired and the specs are 230v +/- 5% 3ph with a neutral and ground! 208 will not work and neither will our 240v 3phase with no neutral or the fact the incoming is +/- 10%. I am waiting response from the mfg. but I was just wondering if anyone else has run into this. I have been in the electrical field for about 15 years and have not seen this before.

 

[Hv&Lv]

I just recieved the specs for a new piece of lab equipment that needs wired and the specs are 230v +/- 5% 3ph with a neutral and ground! 208 will not work and neither will our 240v 3phase with no neutral or the fact the incoming is +/- 10%. I am waiting response from the mfg. but I was just wondering if anyone else has run into this. I have been in the electrical field for about 15 years and have not seen this before.

Sounds like a three phase four wire delta

 

[jim dungar]

Could be 240Y/136V, which is becoming more common for electronic devices with 'rectifier front ends', like VFDs and UPs.

 

[kwired]

I think OP's concern is the marked 230 volt +/- 5%.

240 does fall within 5% but 242 would be outside that 5% range

Edit to add:

He did say his existing system has no neutral so that would be a problem. Sounds like a transformer will be needed to derive a system with a neutral, and you may still need to adjust the voltage somehow if outside the 5% tolerance - maybe with selected line side voltage taps on the transformer?

 

[mgookin]

I just recieved the specs for a new piece of lab equipment that needs wired and the specs are 230v +/- 5% 3ph with a neutral and ground! 208 will not work and neither will our 240v 3phase with no neutral or the fact the incoming is +/- 10%. I am waiting response from the mfg. but I was just wondering if anyone else has run into this. I have been in the electrical field for about 15 years and have not seen this before.

I'd call the manufacturer of the equipment and ask for clarification.

By 230v +/- 5% they may mean you can use 220v, 230v, or 240v, or they may mean the supply has to be 230v nominal and held to the tight 5% tolerance. If the latter, you may need a UPS or an AC Power Source, both of which are expensive.

We have a 0-600 VAC power source in our lab which we use to replicate the power grids around the globe. It's a great piece of equipment.