3 Phase Converters For 3 Phase Consumer

[CalB4676]

Hey, Just looking for a bit of advice for 3-phase converters.

Regular client has asked for a single to 3 phase converter to be able to power a portable containers with 3 phase boards (currently other than using a 3phase generator on other sites, a single to 3 phase plug top is used and powered via single phase 32A commando, making the container work from single phase).

Idea is to change out some single phase compressors to a single 3 phase compressor. Container contains 4x single phase 370w motors with control gear, new 3 phase compressor 5.5kw, couple other bits. Doing a quick calculation for maximum demand calculation with the some information to hand it comes out to Brown 27A, Black 28A, Grey 13A. So therefore purely cause the compressor, need a convertor on the main site to make 3 phase power.

I have only dealt with a 3 phase converter once and that was to power a single item of equipment (CNC Machine). Basically I'm not sure using a 3-phase converter designed to or should at all power container with various equipment.

Anybody seen or have any experience with this before. Any advice or knowledge much apricated.

Looking at possibly about a 15kW/20HP Rotary Converter.

Thanks in advance.

 

[James]

I think to be safe, you should be looking at a 20Kw rotary convertor, that will give you about 30A per phase

however, be aware that it will require more than 80A single phase to supply it.

mind you, you have only listed 4 x 370w and a 5.5kw load.
less than 7kw in total so that would be under 32A single phase.

I think your calculations may be out unless you have some significant loads listed under (couple of other bits)

 

[CalB4676]

I think to be safe, you should be looking at a 20Kw rotary convertor, that will give you about 30A per phase

however, be aware that it will require more than 80A single phase to supply it.

mind you, you have only listed 4 x 370w and a 5.5kw load.
less than 7kw in total so that would be under 32A single phase.

I think your calculations may be out unless you have some significant loads listed under (couple of other bits)

Yeah was just looking there and it recommends a 25mm cable feed with a 80A Fuse within 20mtr. So wont work as they want it installed on the other side of the site to the mains incomer (about 30-40mtrs).

Yeah theres a couple other machines that I cant find anything about a maximum load. just that it contains internally A 12A and 2A schnider MCBs, Fed of a 16A 3 pin so I just taking it as 16A full load x 2. Either way its about the loadings mentioned above.

I'm thinking of talking them down to a converter to purely to supply a 5.5kw compressor and not the whole container as its only one machine requiring it.

Thanks for the comment.

 

[freddo]

Be careful to allow for the starting current in your calculations, depending on the compressor design this can be really quite high, especially if the compressor is a reciprocating type and isn't unloaded during startup.

 

[James]

Be careful to allow for the starting current in your calculations, depending on the compressor design this can be really quite high, especially if the compressor is a reciprocating type and isn't unloaded during startup.

Rotary converters are quite good for starting currents due to the inherent inertia of the rotating mass.