I have had no formal electrical engineering education, my comments maybe incorrect, if so please advice.

I live in a Condominium the main single phase drop is routed via a Main Breaker called Safe-T-Cut that provides a selection between Direct, 25A, 15A, 5A (currently its set to 5A) this is connected to a breaker box with a Main breaker is 10A and individual circuits are at 5A

With some parttime hobby my electrical requirement has gone pass the individual circuit limit of 5A, biggest challenge is that the 7 circuits in the house are divide as such

  • all electrical outlets
  • Aircondition 1
  • Aircon 2
  • Aircon 3
  • Cooker
  • Lights
  • Hot water

(all electrical outlets in 3 rooms are all in one circuit, this is a design which I am foreign to)

I am looking at alternatives, the easiest would be to take another outlet from one of the under utilized of the remaining 6.

I was also wondering If I am doing so would it be beneficial / possible to take both 5A circuits (there will not be other appliances on it)

is there some device that can be used for such composition? where input would be 5A capable line and output is a near 10A (I would limit it to around 8.5A so that I am not reaching the main breaker limit, and adjust safety-cut to 15A)

is it a stabilizer what I would be needing?

UPDATE: each unit in the condominium has a direct connect to the main supply from the provider with a main switch at 30A, condomeniums are individually owned and maintained. Internal wiring at the unit is for the owner of each unit.

I am more interested in a academic aspect of my question as an understanding of it. i read in a 3 phase system where each phase is 60 degrees apart the combination of the phases appears to be somewhat trivial from a high level design and understanding.

so in my case since two circuits of 5A each is coming from the same phase maybe i would require a phase shifter first? (haven't googled that yet, just thought of it as i was writing this sentence)

  • 1
    \$\begingroup\$ Questions like this often get transferred to the Home Improvement Stack Exchange. I am only familiar with North America residential wiring. I suspect the system you describe in unique to your area of the world. To get an answer you will probably need to say where that is. \$\endgroup\$
    – user80875
    Apr 5, 2018 at 0:56
  • \$\begingroup\$ don't mess with the mains supply (safety, legal), contact the owners and request an upgrade, which may not be forthcoming, and wouldn't be free. And that's advice that's applicable to any part of the world. \$\endgroup\$
    – Neil_UK
    Apr 5, 2018 at 5:03
  • \$\begingroup\$ If, as you seem to say, your entire condominium is running through a 5A breaker then it's immaterial what you do after that, you won't get more than 5A whatever you do. Are you sure about those values? 5A barely runs a cooker hob, let alone three air conditioners. \$\endgroup\$
    – Finbarr
    Apr 5, 2018 at 8:52
  • \$\begingroup\$ @CharlesCowie et-el updated the question \$\endgroup\$
    – DevZer0
    Apr 7, 2018 at 7:15
  • \$\begingroup\$ @Neil_UK updated question \$\endgroup\$
    – DevZer0
    Apr 7, 2018 at 7:15

1 Answer 1


If you have a service fed from a 30 amp main switch, you have a single-phase service. How the building 3-phase service is divided is irrelevant (not trivial). If you have a single item of load equipment that requires more than 5 amps, you need a 10, 15 or 25 amp circuit for that. The wire size, circuit breaker and receptacle need to be rated for the required current. No combining of circuits, added stabilizer or other measures can substitute for that.

Your description of the distribution is still unclear. You mention 30 amp switch and 10 amp main breaker. That makes no sense to me. You have a list of loads that contains items including some that must require more than 5 amps.

You need a local electrician to evaluate what you have and install it.

If you want to understand what you have, you should probably search "residential electrical distribution systems in [wherever you live]." Also search "Safe-T-Cut" and the brand name of your distribution box if that is different. Also the model number. For questions about that, post a photo and/or link to manufacturer information.


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