Connecting multiple power supplies together

Dez

Fueled by Christmas - Inspired by You!
Generous elf
Joined
Dec 16, 2014
Messages
140
Location
Toowoomba QLD
Like most people I am planning on having multiple power supplies inside my main controller box.

In regards to wiring on the main input from 240 volts, should I use 3 power leads for 3 power supplies or can I use one lead an daisy chain the others together?

Was just trying neaten things up by having less cables.
 

Mark_M

Full time elf
Generous elf
Joined
Dec 30, 2018
Messages
336
Location
Auckland, NZ
It's not best to daisy chain leads.
If you're not sure then it's best to get an electrician to wire it for you.

[Another post] darylc has said:
ACL is not the place for advice on how to do 230v/mains wiring. Mains wiring should be done by a qualified electrician.
 
  • Like
Reactions: Dez

TerryK

Retired Elf
Joined
Feb 9, 2020
Messages
74
Location
West Central Ohio
As Mark_M mentioned, due to the risk factor when working with the primary side of power supply systems, one needs to seek out and utilize experienced individuals.

To partially answer your question, daisy chaining is not the method that should be used for powering multiple supplies. A single mains infeed cable can be used but it needs to be run to a fused or breakered distribution point allowing each supply to be individually protected. All cables, wiring, and fuses/breakers must be correctly sized which is where the need for someone experienced with the (for your location) Australian electrical code is necessary.
 
  • Like
Reactions: Dez

Dez

Fueled by Christmas - Inspired by You!
Generous elf
Joined
Dec 16, 2014
Messages
140
Location
Toowoomba QLD
Thanks all. I figured it’s best not to but have seen plenty of boxes wired like this. Might go the safer rout
 

scamper

Dedicated elf
Joined
Jan 5, 2014
Messages
1,097
Location
collie
I run a single cable in then switch each supply separately with all the mains behind the first mounting panel.
I could have gone one extra and put breakers on each, but in my main house switch board each cct has it's own earth leakage circuit breaker, so I figured it to be overkill.
 
  • Like
Reactions: Dez

TerryK

Retired Elf
Joined
Feb 9, 2020
Messages
74
Location
West Central Ohio
I run a single cable in then switch each supply separately with all the mains behind the first mounting panel.
I could have gone one extra and put breakers on each, but in my main house switch board each cct has it's own earth leakage circuit breaker, so I figured it to be overkill.
Sitting in the US I'm not terribly familiar with the Australian electrical code, with that in mind if by switch you mean a switch not fuse or breaker and earth leakage circuit breaker as a GFI/ground fault interrupter, I believe there exists an issue with your design. From other posts and the ACL Chat I understand an Australian outlet to be 240 Volt 16 Amp capable. As an example, say one has several (3) Meanwell 350 watt supplies in an enclosure. Typically as a group they'll be pulling 5 to 6 amp from the Mains when pretty well fully loaded. Say one goes bad and tries to pull 10 Amp. Still under the 16 Amp outlet capability, no ground fault (as the fault is across the lines) that supply is consuming 2000 to 2500 watts when designed for no more than 350. If it does not set the enclosure on fire it will smoke very badly. The 240V 16A outlet circuit will never see the fault and happily help torch the enclosure.

Even for a single supply, one really should have a fuse or breaker protecting the enclosure supply primary side. The outlet protection will protect itself and depending upon the supply cable AWG, that cable, maybe. If David_AVD sells a mains fuse device as indicated above, he can correct me if wrong, but I suspect he is thinking along the same lines as I; Mains fusing inside the enclosure is advisable.
 
Last edited:

David_AVD

Really old (now a Grandpa)
Community project designer
Generous elf
Joined
Jun 12, 2010
Messages
4,204
Location
Victoria Point (Brisbane)
The genuine Mean Well power supplies have a fuse on the active (live) input inside the PSU.

How well the generic ones are fused (or correctly rated) I couldn't say.

I still prefer to have individual fuses for each output on the distribution PCB.
 

scamper

Dedicated elf
Joined
Jan 5, 2014
Messages
1,097
Location
collie
am talking the input side here, so if you get a fault that only draws say 10amp and slowly burns, then same could be said if you got a fault that draws 5 amp and does the same.
Being in the electronics repair industry for many years, I have seen just about every possible fault and some that have even caught fire and in 95% of cases The mains fuse is still in tact.
 

Dez

Fueled by Christmas - Inspired by You!
Generous elf
Joined
Dec 16, 2014
Messages
140
Location
Toowoomba QLD
am talking the input side here, so if you get a fault that only draws say 10amp and slowly burns, then same could be said if you got a fault that draws 5 amp and does the same.
Being in the electronics repair industry for many years, I have seen just about every possible fault and some that have even caught fire and in 95% of cases The mains fuse is still in tact.
Thanks for the confidence! Lol! Appreciate your input. Thank you
 

Ltmup

New elf
Joined
Feb 1, 2020
Messages
31
A circuit breakers basic function is to stop the supply cable in your walls from catching fire, what you connect to an outlet is outside of its preview. A safety switch (RCD) is designed to prevent a harmful flow of current to a person under most but not all faults. The outlets in your house are GPO, general purpose outlets , so unless you get a dedicated circuit designed to very specific requirements you are relying on any if any internal protection
 

SAALTFAM

Sparky with Blinky Lights ;-)
Generous elf
Joined
Dec 9, 2019
Messages
68
Location
Bentley Park
New rules every circuit has to be protected by a RCD so don’t fall into any special circuit crap.
Get a licensed electrician to do all the 240v stuff, your life/house/family/loved ones depending on you and your decisions.
 

bpratt

Full time elf
Joined
Mar 31, 2019
Messages
198
Location
Jimboomba, Queensland
New rules every circuit has to be protected by a RCD so don’t fall into any special circuit crap.
Get a licensed electrician to do all the 240v stuff, your life/house/family/loved ones depending on you and your decisions.
Nothing new about that rules. :)


I think the official forum standing is that if it is 230 volts, then that is a job for a licensed electrician ONLY.


If someone has to ask, then they should be going nowhere near 230 volts in the first place. :)
 
Top