Electrical

[Smahk]

Can someone please tell me what does 3 phase 30(100) means?   How many watts can I safely use?  Is this per socket or per floor?  Thanks! 

[sometimewoodworker]

3 phase 30/100 = 3 X 100A X 220V = 66,000W supply, 1 socket is a maximum power draw of 3,500 W. the number of sockets and circuits depends on your usage.

 

These numbers are all theoretical as most people can't draw the maximum power they are rated for without dropping the supply voltage. Others can go 30% over the maximum.

[NanLaew]

On an electric meter.

 

3 phase: Means 3-phase power versus single-phase. You have more than 1 live wire coming in.

 

30: Means 30 A or 30 amperes base load of the meter.

 

(100): Means 100 A or 100 amperes maximum total current load that the meter can handle.

[sometimewoodworker]

2 hours ago, NanLaew said:

On an electric meter.

 

(100???? Means 100 A or 100 amperes maximum total current load that the meter can handle.

Not correct, virtually all meters in Thailand will happily handle a load in excess of the higher number, however they are not  necessarily accurate, they are quite likely to record high, extremely unlikely to record low. 

 

I know of a 5/15 meter that often had a 25A load, no problem or the meter.

[longball53098]

I would have to believe that the manufacturer who makes the meter is only guaranteeing the accuracy of the meter to 100 amps per phase. If you exceed that 100 amp value there is no promise of accuracy or readings or performance of the meter.

[NanLaew]

14 hours ago, sometimewoodworker said:

Not correct, virtually all meters in Thailand will happily handle a load in excess of the higher number, however they are not  necessarily accurate, they are quite likely to record high, extremely unlikely to record low. 

OK, how about...

 

(100) : Means 100 A or 100 amperes maximum total current load that the meter can accurately handle.

[Smahk]

So....100amp max. Is that 100 total?  Or I can use 100amp x 3 ? 

[bankruatsteve]

4 hours ago, Smahk said:

So....100amp max. Is that 100 total?  Or I can use 100amp x 3 ? 

Running as 3 single-phase supply, you could theoretically use 3 x 100amp.  That's a LOT of power for domestic use.

[sometimewoodworker]

6 hours ago, Smahk said:

So....100amp max. Is that 100 total?  Or I can use 100amp x 3 ? 

Did you read my reply to your original post? 

On 5/29/2019 at 7:29 PM, sometimewoodworker said:

 

3 phase 30/100 = 3 X 100A X 220V = 66,000W

 

66,000 watt / 220 = 300A 

 

As mentioned that ts not the maximum as the meters will pass more current.

 

As also mentioned you may pull the supply voltage down with increasing load so be unable to get anywhere near 300A.

[mahjongguy]

I'm curious about the OP's situation. Normal single-phase residential meters here are 5(15), 15(45), or 30(100). Three-phase meters are nearly always three times 30(45), with the main breaker at 60 amps total. 

 

 

 

 

 

 

 

 

[bankruatsteve]

23 minutes ago, mahjongguy said:

Three-phase meters are nearly always three times 30(45), with the main breaker at 60 amps total. 

That would be 3 x 15/45 for "normal" 3-phase.

[mahjongguy]

Yup. Sorry. Just more proof that decaf coffee doesn't do the job.

[sometimewoodworker]

1 hour ago, bankruatsteve said:

That would be 3 x 15/45 for "normal" 3-phase.

3-phase has 2 meter options, though I haven't heard of anyone getting the bigger meter ( 3 x 30/100) it is one of the options that is available if the PEA will let you have it. 

 

Certaly virtually every 3 phase supply that I've seen uses 3 x 15/45, once you are into the need for the bigger meter you will probably be using enough to make a 22kv supply and your own transformer a sensible option.